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Sample records for cardiovascular responses produced

  1. Cardiovascular responses to repetitive exposure to hyper- and hypogravity states produced by parabolic flight

    NASA Technical Reports Server (NTRS)

    Mukai, C. N.; Lathers, C. M.; Charles, J. B.; Bennett, B. S.

    1994-01-01

    Physiologic changes to repetitive hyper- and hypogravity stresses occurring during eight to ten parabolas on NASA's KC-135 aircraft were studied. Hemodynamic responses in 11 subjects in 4 different postures (supine, standing, sitting, and semisupine Space Shuttle launch position) were determined using noninvasive impedance cardiography. Five seconds of heart rate, cardiac index, thoracic fluid index, stroke index, ejection velocity index, and ventricular ejection time data were averaged during four different gravity (g) states: 1.3g (before parabola onset); 1.9g (parabola entry); 0g (parabola peak); and 1.7g (parabola exit) for each subject. The standing position was associated with the largest changes in the cardiovascular response to hypo- and hypergravity. The thoracic fluid index did not indicate a headward redistribution during transition from a simulated launch position to weightlessness. Analysis of the eight to ten parabolas revealed that, in general, values obtained at 1.8g differed from 1.6g, 0g differed from 1.6 and 1.3g, and 1.6g differed from 1.3g. The factors of gravity, thoracic fluid index, and cardiac index exhibited significant differences that were most likely to occur between parabola 1 versus parabolas 6, 7, and 8, and parabola 2 versus parabolas 4 through 8. Only the parameter of thoracic fluid index exhibited significance for parabolas 3 versus parabolas 6 and 7.

  2. AV3V lesions attenuate the cardiovascular responses produced by blood-borne excitatory amino acid analogs

    NASA Technical Reports Server (NTRS)

    Whalen, E. J.; Beltz, T. G.; Lewis, S. J.; Johnson, A. K.

    1999-01-01

    Systemic injections of the excitatory amino acid (EAA) analogs, kainic acid (KA) and N-methyl-D-aspartate (NMDA), produce a pressor response in conscious rats that is caused by a centrally mediated activation of sympathetic drive and the release of arginine vasopressin (AVP). This study tested the hypothesis that the tissue surrounding the anteroventral part of the third ventricle (AV3V) plays a role in the expression of the pressor responses produced by systemically injected EAA analogs. Specifically, we examined whether prior electrolytic ablation of the AV3V region would affect the pressor responses to KA and NMDA (1 mg/kg iv) in conscious rats. The KA-induced pressor response was smaller in AV3V-lesioned than in sham-lesioned rats (11 +/- 2 vs. 29 +/- 2 mmHg; P < 0.05). After ganglion blockade, KA produced a pressor response in sham-lesioned but not AV3V-lesioned rats (+27 +/- 3 vs. +1 +/- 2 mmHg; P < 0.05). The KA-induced pressor response in ganglion-blocked sham-lesioned rats was abolished by a vasopressin V1-receptor antagonist. Similar results were obtained with NMDA. The pressor response to AVP (10 ng/kg iv) was slightly smaller in AV3V-lesioned than in sham-lesioned ganglion-blocked rats (45 +/- 3 vs. 57 +/- 4 mmHg; P < 0.05). This study demonstrates that the pressor responses to systemically injected EAA analogs are smaller in AV3V-lesioned rats. The EAA analogs may produce pressor responses by stimulation of EAA receptors in the AV3V region, or the AV3V region may play an important role in the expression of these responses.

  3. Cardiovascular responses to spaceflight

    NASA Technical Reports Server (NTRS)

    Nicogossian, A.; Pool, S. L.; Rambaut, P. C.

    1983-01-01

    The cardiovascular system's adaptive changes during and after spaceflight are discussed. Cephalic fluid shifts are demonstrated by photographs along with calf girth and leg volume changes. Inflight measurements show an increase in average resting heart rate and systolic blood pressure, and a sympathetic-parasympathetic neural imbalance. Postflight findings include a small but reversible decrease in the left ventricular muscle mass. Since 1980, NASA's research has emphasized cardiovascular deconditioning and countermeasures: hemodynamic changes, endocrine and neurohumoral aspects, etiologic factors, and lower body negative pressure devices. Though human beings acclimate to the space environment, questions concerning the immediate and long-term aspects of spaceflight need to be answered for adequate planning of extended space missions.

  4. Cardiovascular response to thermoregulatory challenges.

    PubMed

    Liu, Cuiqing; Yavar, Zubin; Sun, Qinghua

    2015-12-01

    A growing number of extreme climate events are occurring in the setting of ongoing climate change, with an increase in both the intensity and frequency. It has been shown that ambient temperature challenges have a direct and highly varied impact on cardiovascular health. With a rapidly growing amount of literature on this issue, we aim to review the recent publications regarding the impact of cold and heat on human populations with regard to cardiovascular disease (CVD) mortality/morbidity while also examining lag effects, vulnerable subgroups, and relevant mechanisms. Although the relative risk of morbidity/mortality associated with extreme temperature varied greatly across different studies, both cold and hot temperatures were associated with a positive mean excess of cardiovascular deaths or hospital admissions. Cause-specific study of CVD morbidity/mortality indicated that the sensitivity to temperature was disease-specific, with different patterns for acute and chronic ischemic heart disease. Vulnerability to temperature-related mortality was associated with some characteristics of the populations, including sex, age, location, socioeconomic condition, and comorbidities such as cardiac diseases, kidney diseases, diabetes, and hypertension. Temperature-induced damage is thought to be related to enhanced sympathetic reactivity followed by activation of the sympathetic nervous system, renin-angiotensin system, as well as dehydration and a systemic inflammatory response. Future research should focus on multidisciplinary adaptation strategies that incorporate epidemiology, climatology, indoor/building environments, energy usage, labor legislative perfection, and human thermal comfort models. Studies on the underlying mechanism by which temperature challenge induces pathophysiological response and CVD await profound and lasting investigation.

  5. Cardiovascular responses of snakes to hypergravity

    NASA Technical Reports Server (NTRS)

    Lillywhite, H. B.; Ballard, R. E.; Hargens, A. R.; Rosenberg, H. I.

    1997-01-01

    Snakes have provided useful vertebrate models for understanding circulatory adaptation to gravity, attributable to their elongate body shape and evolutionary diversificaton in terms of ecology and behavior. Recently we have studied cardiovascular responses of snakes to hypergravic acceleration forces produced acutely in the head-to-tail direction (+Gz) on a short-arm centrifuge. Snakes were held in a nearly straight position within a horizontal plastic tube and subjected to a linear force gradient during acceleration. Carotid blood flow provided an integrated measure of cardiovascular performance. Thus, cardiovascular tolerance of snakes to stepwise increments of Gz was measured as the caudal Gz force at which carotid blood flow ceased. Tolerance to increasing Gz varies according to adaptive evolutionary history inferred from the ecology and behavior of species. With respect to data for six species we investigated, multiple regression analysis demonstrates that Gz tolerance correlates with gravitational habitat, independently of body length. Relative to aquatic and non-climbing species, carotid blood flow is better maintained in arboreal or scansorial species, which tolerate hypergravic forces of +2 to +3.5 Gz. Additionally, semi-arboreal rat snakes (Elaphe obsoleta) exhibit plasticity of responses to long-term, intermittent +1.5 Gz stress. Compared to non-acclimated controls, acclimated snakes show greater increases of heart rate during head-up tilt or acceleration, greater sensitivity of arterial pressure to circulating catecholamines, higher blood levels of prostaglandin ratios favorable to maintenance of arterial blood pressure, and medial hypertrophy in major arteries and veins. As in other vertebrates, Gz tolerance of snakes is enhanced by acclimation, high arterial pressure, comparatively large blood volume, and body movements. Vascular studies of snakes suggest the importance to acclimation of local responses involving vascular tissue, in addition to

  6. Role of the anterior region of the third ventricle in the cardiovascular responses produced by systemic injection of a nitric oxide synthase inhibitor

    NASA Technical Reports Server (NTRS)

    Lewis, S. J.; Whalen, E. J.; Beltz, T. G.; Johnson, A. K.

    1999-01-01

    This study examined whether a prior electrolytic lesion of the tissue surrounding the anteroventral third ventricle (AV3V) would affect the increase in mean arterial blood pressure (MAP) and the fall in heart rate (HR) produced by systemic injection of the nitric oxide synthesis (NOS) inhibitor, NG-nitro-L-arginine methyl ester (L-NAME; 25 micromol/kg, i.v.) in conscious rats. L-NAME produced a smaller increase in MAP in AV3V-lesion than in sham-lesion rats (+19+/-3 vs. +40+/-3 mmHg, respectively; P<0.05). In contrast, L-NAME produced similar falls in HR in the AV3V-lesion and sham-lesion rats (-103+/-15 vs. -97+/-8 bpm, respectively; P<0.05). These findings demonstrate that the L-NAME-induced pressor response is dependent upon the integrity of the AV3V region, whereas the L-NAME-induced bradycardia is not. Copyright 1999 Elsevier Science B. V.

  7. Cardiovascular responses to hypogravic environments

    NASA Technical Reports Server (NTRS)

    Sandler, H.

    1983-01-01

    The cardiovascular deconditioning observed during and after space flight is characterized in a review of human space and simulation studies and animal simulations. The various simulation techniques (horizontal bed rest, head-down tilt, and water immersion in man, and immobilization of animals) are examined, and sample results are presented in graphs. Countermeasures such as exercise regimens, fluid replacement, drugs, venous pooling, G-suits, oscillating beds, electrostimulation of muscles, lower-body negative pressure, body-surface cooling, and hypoxia are reviewed and found to be generally ineffective or unreliable. The need for future space experimentation in both humans and animals is indicated.

  8. Endocannabinoids and the cardiovascular response to stress.

    PubMed

    O'Sullivan, Saoirse E; Kendall, Patrick J; Kendall, David A

    2012-01-01

    Stress activates the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS), resulting in cardiovascular responses. The endocannabinoid system (ECS), a ubiquitously expressed lipid signalling system, modulates both HPA and SNS activity. The purpose of this review is to explore the possible involvement/role of the ECS in the cardiovascular response to stress. The ECS has numerous cardiovascular effects including modulation of blood pressure, heart rate, the baroreflex, and direct vascular actions. It is also involved in a protective manner in response to stressors in cardiac preconditioning, and various stressors (for example, pain, orthostasis and social stress) increase plasma levels of endocannabinoids. Given the multitude of vascular effects of endocannabinoids, this is bound to have consequences. Beneficial effects of ECS upregulation could include cardioprotection, vasodilatation, CB(2)-mediated anti-inflammatory effects and activation of peroxisome proliferator-activated receptors. Negative effects of endocannabinoids could include mediation of the effects of glucocorticoids, CB(1)-mediated metabolic changes, and metabolism to vasoconstrictor products. It is also likely that there is a central role for the ECS in modulating cardiovascular activity via the HPA and SNS. However, much more work is required to fully integrate the role of the ECS in mediating many of the physiological responses to stress, including cardiovascular responses.

  9. Oxytocin in the cardiovascular responses to stress.

    PubMed

    Wsol, A; Cudnoch-Jedrzejewska, A; Szczepanska-Sadowska, E; Kowalewski, S; Puchalska, L

    2008-12-01

    The present study was designed to determine the role of central oxytocin (OXY) in regulation of the cardiovascular responses to the alarming stress. Three groups of male, normotensive Sprague Dawley rats, received intracerebroventricular (i.c.v.) infusion of one of the following: 1) vehicle, 2) OXY or 3) OXY antagonist (OXANT). Mean arterial blood pressure (MABP) and heart rate (HR) were recorded at rest, during and after application of the alarming stressor (air jet). Under resting conditions the i.c.v. infusions of vehicle, OXY or OXYANT did not influence the cardiovascular parameters. The alarming stressor evoked significant increases in MABP and HR that were significantly greater in the rats receiving i.c.v. infusion of oxytocin antagonist than in those receiving vehicle or OXY. The study provides evidence that stimulation of the brain oxytocin receptors by endogenous oxytocin plays significant role in inhibition of cardiovascular responses to stress.

  10. Environmental producer responsibility.

    PubMed

    Evans, J L

    1997-05-01

    The Packaging and Packaging Waste Directive (P&PWD) requires manufacturers to take responsibility for recovering packaging waste. This article examines some of the challenges this presents. Product designers must now integrate environmental regulations into product and packaging design. This will entail handling the conflict between the differing requirements of the P&PWD and the Medical Device Directive, and marking products to indicate whether packaging is reusable or recyclable. PMID:10167685

  11. Meditation can produce beneficial effects to prevent cardiovascular disease.

    PubMed

    Koike, Marcia Kiyomi; Cardoso, Roberto

    2014-06-01

    Coronary heart disease is the major cause of global cardiovascular mortality and morbidity. Lifestyle behaviour contributes as a risk factor: unhealthy diet, sedentary lifestyle, tobacco, alcohol, hypertension, diabetes, dyslipidemia and psychosocial stress. Atherosclerosis pathologic mechanisms involving oxidative stress, dyslipidemia, inflammation and senescence are associated with arterial wall damage and plaque formation. Stress reduction was observed in several types of meditation. After meditation, hormonal orchestration modulates effects in the central nervous system and in the body. All types of meditation are associated with blood pressure control, enhancement in insulin resistance, reduction of lipid peroxidation and cellular senescence, independent of type of meditation. This review presents scientific evidence to explain how meditation can produce beneficial effects on the cardiovascular system, and particularly regarding vascular aspects.

  12. The cardiovascular response to the AGS

    NASA Technical Reports Server (NTRS)

    Cardus, David; Mctaggart, Wesley G.

    1993-01-01

    This paper reports the preliminary results of experiments on human subjects conducted to study the cardiovascular response to various g-levels and exposure times using an artificial gravity simulator (AGS). The AGS is a short arm centrifuge consisting of a turntable, a traction system, a platform and four beds. Data collection hardware is part of the communication system. The AGS provides a steep acceleration gradient in subjects in the supine position.

  13. Human cardiovascular responses to passive heat stress.

    PubMed

    Crandall, Craig G; Wilson, Thad E

    2015-01-01

    Heat stress increases human morbidity and mortality compared to normothermic conditions. Many occupations, disease states, as well as stages of life are especially vulnerable to the stress imposed on the cardiovascular system during exposure to hot ambient conditions. This review focuses on the cardiovascular responses to heat stress that are necessary for heat dissipation. To accomplish this regulatory feat requires complex autonomic nervous system control of the heart and various vascular beds. For example, during heat stress cardiac output increases up to twofold, by increases in heart rate and an active maintenance of stroke volume via increases in inotropy in the presence of decreases in cardiac preload. Baroreflexes retain the ability to regulate blood pressure in many, but not all, heat stress conditions. Central hypovolemia is another cardiovascular challenge brought about by heat stress, which if added to a subsequent central volumetric stress, such as hemorrhage, can be problematic and potentially dangerous, as syncope and cardiovascular collapse may ensue. These combined stresses can compromise blood flow and oxygenation to important tissues such as the brain. It is notable that this compromised condition can occur at cardiac outputs that are adequate during normothermic conditions but are inadequate in heat because of the increased systemic vascular conductance associated with cutaneous vasodilation. Understanding the mechanisms within this complex regulatory system will allow for the development of treatment recommendations and countermeasures to reduce risks during the ever-increasing frequency of severe heat events that are predicted to occur.

  14. Human Cardiovascular Responses to Passive Heat Stress

    PubMed Central

    Crandall, Craig G.; Wilson, Thad E.

    2016-01-01

    Heat stress increases human morbidity and mortality compared to normothermic conditions. Many occupations, disease states, as well as stages of life are especially vulnerable to the stress imposed on the cardiovascular system during exposure to hot ambient conditions. This review focuses on the cardiovascular responses to heat stress that are necessary for heat dissipation. To accomplish this regulatory feat requires complex autonomic nervous system control of the heart and various vascular beds. For example, during heat stress cardiac output increases up to twofold, by increases in heart rate and an active maintenance of stroke volume via increases in inotropy in the presence of decreases in cardiac preload. Baroreflexes retain the ability to regulate blood pressure in many, but not all, heat stress conditions. Central hypovolemia is another cardiovascular challenge brought about by heat stress, which if added to a subsequent central volumetric stress, such as hemorrhage, can be problematic and potentially dangerous, as syncope and cardiovascular collapse may ensue. These combined stresses can compromise blood flow and oxygenation to important tissues such as the brain. It is notable that this compromised condition can occur at cardiac outputs that are adequate during normothermic conditions but are inadequate in heat because of the increased systemic vascular conductance associated with cutaneous vasodilation. Understanding the mechanisms within this complex regulatory system will allow for the development of treatment recommendations and countermeasures to reduce risks during the ever-increasing frequency of severe heat events that are predicted to occur. PMID:25589263

  15. Xenobiotic pulmonary exposure and systemic cardiovascular response via neurological links.

    PubMed

    Stapleton, Phoebe A; Abukabda, Alaeddin B; Hardy, Steven L; Nurkiewicz, Timothy R

    2015-11-15

    The cardiovascular response to xenobiotic particle exposure has been increasingly studied over the last two decades, producing an extraordinary scope and depth of research findings. With the flourishing of nanotechnology, the term "xenobiotic particles" has expanded to encompass not only air pollution particulate matter (PM) but also anthropogenic particles, such as engineered nanomaterials (ENMs). Historically, the majority of research in these fields has focused on pulmonary exposure and the adverse physiological effects associated with a host inflammatory response or direct particle-tissue interactions. Because these hypotheses can neither account entirely for the deleterious cardiovascular effects of xenobiotic particle exposure nor their time course, the case for substantial neurological involvement is apparent. Indeed, considerable evidence suggests that not only is neural involvement a significant contributor but also a reality that needs to be investigated more thoroughly when assessing xenobiotic particle toxicities. Therefore, the scope of this review is several-fold. First, we provide a brief overview of the major anatomical components of the central and peripheral nervous systems, giving consideration to the potential biologic targets affected by inhaled particles. Second, the autonomic arcs and mechanisms that may be involved are reviewed. Third, the cardiovascular outcomes following neurological responses are discussed. Lastly, unique problems, future risks, and hurdles associated with xenobiotic particle exposure are discussed. A better understanding of these neural issues may facilitate research that in conjunction with existing research, will ultimately prevent the untoward cardiovascular outcomes associated with PM exposures and/or identify safe ENMs for the advancement of human health. PMID:26386111

  16. Airway reflexes, autonomic function, and cardiovascular responses.

    PubMed Central

    Widdicombe, J; Lee, L Y

    2001-01-01

    In this article, we review the cardiovascular responses to the inhalation of irritants and pollutants. Many sensory receptors in the respiratory system, from nose to alveoli, respond to these irritants and set up powerful reflex changes, including those in the cardiovascular system. Systemic hypotension or hypertension, pulmonary hypertension, bradycardia, tachycardia, and dysrhythmias have all been described previously. Most of the experiments have been acute and have been performed on anesthetized experimental animals. Experiments on humans suggest we have similar sensory systems and reflex responses. However, we must use caution when applying the animal results to humans. Most animal experiments, unlike those with humans, have been performed using general anesthesia, with irritants administered in high concentrations, and often to a restricted part of the respiratory tract. Species differences in the response to irritants are well established. We must be even more careful when applying the results of acute experiments in animals to the pathophysiologic changes observed in prolonged exposure to environmental pollution in humans. PMID:11544167

  17. Cocaine and methamphetamine produce different patterns of subjective and cardiovascular effects.

    PubMed

    Newton, Thomas F; De La Garza, Richard; Kalechstein, Ari D; Nestor, Liam

    2005-09-01

    The stimulant effects of cocaine and methamphetamine are mediated by changes in synaptic concentrations of brain monoamines; however, the drugs alter monoamine levels via different mechanisms. This study examined the subjective and cardiovascular responses produced by investigational administration of cocaine or methamphetamine, in order to examine the onset and patterns of subjective and cardiovascular responses. Subjects included 14 non-treatment seeking cocaine-dependent and 11 non-treatment seeking methamphetamine-dependent volunteers. As part of ongoing research studies, cocaine and methamphetamine subjects received cocaine (40 mg, IV) or methamphetamine (30 mg, IV), respectively. Subjective and cardiovascular responses were assessed for 30 min and 60 min, respectively. The data reveal significant within groups differences for all subjective effects and cardiovascular effects (p<0.05). Significant between group differences in subjective effects were observed for "Any Drug Effect" (p<.008 for group, and p<.029 for group x time), for "High" (p<.002 for group, and p<.0001 for group x time) and for "Stimulated" (p<.001 for group, and p<.006 for group x time). Significant between group differences in cardiovascular effects were observed for Systolic blood pressure (p<.0001 for group, and p<.002 for group x time), Diastolic blood pressure (p<.0001 for group, though p=NS for group x time), and for Heart Rate (p<.0001 for group, and p<.0001 for group x time). The only difference between the groups for placebo was for heart rate, where there was a significant group x time effect (p<.005). Taken together, the data reveal that the subjective effects of cocaine tended to peak and then decline more rapidly than those produced by methamphetamine. The subjective effects of methamphetamine tended to rise more slowly, and remain elevated longer. Cardiovascular effects of cocaine and methamphetamine had similar onset, but effects of cocaine tended to decline more rapidly

  18. Modeling of Cardiovascular Response to Weightlessness

    NASA Technical Reports Server (NTRS)

    Sharp, M. Keith

    1999-01-01

    It was the hypothesis of this Project that the Simple lack of hydrostatic pressure in microgravity generates several purely physical reactions that underlie and may explain, in part, the cardiovascular response to weightlessness. For instance, hydrostatic pressure within the ventricles of the heart may improve cardiac performance by promoting expansion of ventricular volume during diastole. The lack of hydrostatic pressure in microgravity might, therefore, reduce diastolic filling and cardiac performance. The change in transmural pressure is possible due to the difference in hydrostatic pressure gradients between the blood inside the ventricle and the lung tissue surrounding the ventricle due to their different densities. On the other hand, hydrostatic pressure within the vasculature may reduce cardiac inlet pressures because of the typical location of the heart above the hydrostatic indifference level (the level at which pressure remains constant throughout changes in gravity). Additional physical responses of the body to changing gravitational conditions may influence cardiovascular performance. For instance, fluid shifts from the lower body to the thorax in microgravity may serve to increase central venous pressure (CVP) and boost cardiac output (CO). The concurrent release of gravitational force on the rib cage may tend to increase chest girth and decrease pedcardial pressure, augmenting ventricular filling. The lack of gravity on pulmonary tissue may allow an upward shifting of lung mass, causing a further decrease in pericardial pressure and increased CO. Additional effects include diuresis early in the flight, interstitial fluid shifts, gradual spinal extension and movement of abdominal mass, and redistribution of circulatory impedance because of venous distention in the upper body and the collapse of veins in the lower body. In this project, the cardiovascular responses to changes in intraventricular hydrostatic pressure, in intravascular hydrostatic

  19. Gravitational effects on human cardiovascular responses to isometric muscle contractions

    NASA Astrophysics Data System (ADS)

    Bonde-Petersen, Flemmig; Suzuki, Yoji; Sadamoto, Tomoko

    Isometric exercise induces profound cardiovascular adaptations increasing mean arterial pressure and heart rate. We investigated effects of simulated +Gz and -Gz respectively on the central and peripheral cardiovascular system. Sustained handgrip exercise was performed at 40% of maximum for 2 minutes in five subjects. This maneuver increased mean arterial pressure by 40-45 mm Hg both during head out water immersion which simulates weightlessness, as well as bedrest during -25, 0, and +25 degrees tilt from the horizontal. Lower body negative pressure (-60 mm Hg for 10 min) attenuated the response to handgrip exercise to 30 mm Hg. It also increased the heart rate minimally by about 20 beats per minute while the water immersion, as well as head up, head down and horizontal bedrest showed increments of about 50 beats per min. It was concluded that the response to isometric contraction is mediated through the high pressure baroreceptors, because similar responses were seen during stresses producing a wide variation in central venous pressure. During lower body negative pressure the increased sympathetic nervous activity itself increased resting heart rate and mean arterial pressure. The responses to static exercise were, therefore, weaker.

  20. Metabolic and Cardiovascular Responses of Children during Prolonged Physical Activity.

    ERIC Educational Resources Information Center

    Chausow, Sharon A.; And Others

    1984-01-01

    Metabolic and cardiovascular responses during 45 minutes of continuous moderate intensity exercise were investigated in 11 children, 8-11 years of age. Results indicate that children exhibit metabolic and cardiovascular adjustments similar to those noted in adults during prolonged exercise. (Author/JMK)

  1. Simultaneous cerebrovascular and cardiovascular responses during presyncope

    NASA Technical Reports Server (NTRS)

    Bondar, R. L.; Kassam, M. S.; Stein, F.; Dunphy, P. T.; Fortney, S.; Riedesel, M. L.

    1995-01-01

    BACKGROUND AND PURPOSE: Presyncope, characterized by symptoms and signs indicative of imminent syncope, can be aborted in many situations before loss of consciousness occurs. The plasticity of cerebral autoregulation in healthy humans and its behavior during this syncopal prodrome are unclear, although systemic hemodynamic instability has been suggested as a key factor in the precipitation of syncope. Using lower body negative pressure (LBNP) to simulate central hypovolemia, we previously observed falling mean flow velocities (MFVs) with maintained mean arterial blood pressure (MABP). These findings, and recent reports suggesting increased vascular tone within the cerebral vasculature at presyncope, cannot be explained by the classic static cerebral autoregulation curve; neither can they be totally explained by a recent suggestion of a rightward shift in this curve. METHODS: Four male and five female healthy volunteers were exposed to presyncopal LBNP to evaluate their cerebrovascular and cardiovascular responses by use of continuous acquisition of MFV from the right middle cerebral artery with transcranial Doppler sonography, MABP (Finapres), and heart rate (ECG). RESULTS: At presyncope, MFV dropped on average by 27.3 +/- 14% of its baseline value (P < .05), while MABP remained at 2.0 +/- 27% above its baseline level. Estimated cerebrovascular resistance increased during LBNP. The percentage change from baseline to presyncope in MFV and MABP revealed consistent decreases in MFV before MABP. CONCLUSIONS: Increased estimated cerebrovascular resistance, falling MFV, and constant MABP are evidence of an increase in cerebral vascular tone with falling flow, suggesting a downward shift in the cerebral autoregulation curve. Cerebral vessels may have a differential sensitivity to sympathetic drive or more than one type of sympathetic innervation. Future work to induce dynamic changes in MABP during LBNP may help in assessing the plasticity of the cerebral autoregulation

  2. Test anxiety and cardiovascular responses to daily academic stressors.

    PubMed

    Conley, Kristen M; Lehman, Barbara J

    2012-02-01

    Routine academic events may cause stress and produce temporary elevations in blood pressure. Students who experience test anxiety may be especially prone to cardiovascular activation in response to academic stress. This study drew on self-reported stress and ambulatory blood pressure measurements provided by 99 undergraduate participants (30% men, mean age=21 years) who participated over 4 days. Posture, activity level, recent consumption and the previous same-day reading were considered as covariates in a series of hierarchical linear models. Results indicate elevations in systolic blood pressure at times of acute academic stressors; neither diastolic blood pressure nor heart rate was linked with academic stress. In addition, those participants higher in test anxiety exhibited especially pronounced elevations in systolic blood pressure during times of acute academic stress. This research suggests that everyday academic stressors are linked with temporary increases in blood pressure and that test anxiety may contribute to these elevations. Test anxiety has implications for future academic and job success, and cardiovascular responses to everyday stress may contribute to health problems later in life.

  3. Radiation response of the canine cardiovascular system

    SciTech Connect

    Gavin, P.R.; Gillette, E.L.

    1982-06-01

    The hearts of dogs were irradiated with /sup 60/Co ..gamma.. rays. The dose required to produce pericardial effusion in 50% of the dogs by 180 days (PED/sub 50///sub 180/) was 1220 rad. For cardiac tamponade, the CTD /sub 50///sub 180/ was 1500 rad. Morphometric analyses of the hearts showed decreased capillary volume and increased fibrosis as radiation dose increased. The pericardial thickness increased with increased radiation dose. The slopes of the dose response for these parameters were similar as determined by linear regression of the parameter versus radiation dose.

  4. Gender-based differences in the cardiovascular response to standing

    NASA Technical Reports Server (NTRS)

    Gotshall, Robert W.; Tsai, Pai-Feng; Frey, Mary A. B.

    1991-01-01

    The cardiovascular responses of men and women to the stand test were compared by measuring respective values for heart rate, blood pressure, stroke volume, cardiac output, and total peripheral resistance during a 5-min supine and a 5-min standing test in ten subjects of each gender. It was found that, while the male and female subjects had similar heart rate values, all other responses exhibited greater changes in men than in women. While differences in the height of the subjects did not account for differences in cardiovascular responses, no mechanism responsible for these differences could be identified.

  5. Computational modelling and evaluation of cardiovascular response under pulsatile impeller pump support

    PubMed Central

    Shi, Yubing; Brown, Alistair G.; Lawford, Patricia V.; Arndt, Andreas; Nuesser, Peter; Hose, D. Rodney

    2011-01-01

    This study presents a numerical simulation of cardiovascular response in the heart failure condition under the support of a Berlin Heart INCOR impeller pump-type ventricular assist device (VAD). The model is implemented using the CellML modelling language. To investigate the potential of using the Berlin Heart INCOR impeller pump to produce physiologically meaningful arterial pulse pressure within the various physiological constraints, a series of VAD-assisted cardiovascular cases are studied, in which the pulsation ratio and the phase shift of the VAD motion profile are systematically changed to observe the cardiovascular responses in each of the studied cases. An optimization process is proposed, including the introduction of a cost function to balance the importance of the characteristic cardiovascular variables. Based on this cost function it is found that a pulsation ratio of 0.35 combined with a phase shift of 200° produces the optimal cardiovascular response, giving rise to a maximal arterial pulse pressure of 12.6 mm Hg without inducing regurgitant pump flow while keeping other characteristic cardiovascular variables within appropriate physiological ranges. PMID:22670203

  6. Computational modelling and evaluation of cardiovascular response under pulsatile impeller pump support.

    PubMed

    Shi, Yubing; Brown, Alistair G; Lawford, Patricia V; Arndt, Andreas; Nuesser, Peter; Hose, D Rodney

    2011-06-01

    This study presents a numerical simulation of cardiovascular response in the heart failure condition under the support of a Berlin Heart INCOR impeller pump-type ventricular assist device (VAD). The model is implemented using the CellML modelling language. To investigate the potential of using the Berlin Heart INCOR impeller pump to produce physiologically meaningful arterial pulse pressure within the various physiological constraints, a series of VAD-assisted cardiovascular cases are studied, in which the pulsation ratio and the phase shift of the VAD motion profile are systematically changed to observe the cardiovascular responses in each of the studied cases. An optimization process is proposed, including the introduction of a cost function to balance the importance of the characteristic cardiovascular variables. Based on this cost function it is found that a pulsation ratio of 0.35 combined with a phase shift of 200° produces the optimal cardiovascular response, giving rise to a maximal arterial pulse pressure of 12.6 mm Hg without inducing regurgitant pump flow while keeping other characteristic cardiovascular variables within appropriate physiological ranges.

  7. Computer model of cardiovascular control system responses to exercise

    NASA Technical Reports Server (NTRS)

    Croston, R. C.; Rummel, J. A.; Kay, F. J.

    1973-01-01

    Approaches of systems analysis and mathematical modeling together with computer simulation techniques are applied to the cardiovascular system in order to simulate dynamic responses of the system to a range of exercise work loads. A block diagram of the circulatory model is presented, taking into account arterial segments, venous segments, arterio-venous circulation branches, and the heart. A cardiovascular control system model is also discussed together with model test results.

  8. Central autonomic network mediates cardiovascular responses to acute inflammation: Relevance to increased cardiovascular risk in depression?

    PubMed Central

    Harrison, Neil A.; Cooper, Ella; Voon, Valerie; Miles, Ken; Critchley, Hugo D.

    2013-01-01

    Inflammation is a risk factor for both depression and cardiovascular disease. Depressed mood is also a cardiovascular risk factor. To date, research into mechanisms through which inflammation impacts cardiovascular health rarely takes into account central effects on autonomic cardiovascular control, instead emphasizing direct effects of peripheral inflammatory responses on endothelial reactivity and myocardial function. However, brain responses to inflammation engage neural systems for motivational and homeostatic control and are expressed through depressed mood state and changes in autonomic cardiovascular regulation. Here we combined an inflammatory challenge, known to evoke an acute reduction in mood, with neuroimaging to identify the functional brain substrates underlying potentially detrimental changes in autonomic cardiovascular control. We first demonstrated that alterations in the balance of low to high frequency (LF/HF) changes in heart rate variability (a measure of baroreflex sensitivity) could account for some of the inflammation-evoked changes in diastolic blood pressure, indicating a central (rather than solely local endothelial) origin. Accompanying alterations in regional brain metabolism (measured using 18FDG-PET) were analysed to localise central mechanisms of inflammation-induced changes in cardiovascular state: three discrete regions previously implicated in stressor-evoked blood pressure reactivity, the dorsal anterior and posterior cingulate and pons, strongly mediated the relationship between inflammation and blood pressure. Moreover, activity changes within each region predicted the inflammation-induced shift in LF/HF balance. These data are consistent with a centrally-driven component originating within brain areas supporting stressor evoked blood pressure reactivity. Together our findings highlight mechanisms binding psychological and physiological well-being and their perturbation by peripheral inflammation. PMID:23416033

  9. Early growth response-1 in the pathogenesis of cardiovascular disease.

    PubMed

    Khachigian, Levon M

    2016-07-01

    This article reviews the regulatory roles of the immediate-early gene product and prototypic zinc finger transcription factor, early growth response-1 in models of cardiovascular pathobiology, focusing on insights using microRNA, DNAzymes, small hairpin RNA, small interfering RNA, oligonucleotide decoy strategies and mice deficient in early growth response-1. PMID:27251707

  10. Gender-Related Differences in Cardiovascular Responses to Orthostatic Stress

    NASA Technical Reports Server (NTRS)

    Fritsch-Yelle, Janice M.; DAunno, Dominick S.; Waters, Wendy W.; Freeman-Perez, Sondra

    1999-01-01

    There is evidence that men and women have different cardiovascular responses to standing, and that women are more susceptible to orthostatic hypotension than men. The present study seeks to determine if decreased orthostatic tolerance in women is caused by diminished vasoconstrictive responses.

  11. Cardiovascular responses to weightlessness and ground-based simulations

    NASA Technical Reports Server (NTRS)

    Sandler, H.

    1982-01-01

    Mission experience, from NASA and Soviet programs, on human cardiovascular responses to weightlessness, and the ability of bed rest studies to simulate these are discussed. In-flight effects include fluid shift to the upper body, decreased heart size, bone demineralization, orthostatic intolerance, and loss of exercise tolerance. All the cardiovascular changes that occur with weightlessness also occur with prolonged bed rest. They are most manifest when subjects stand suddenly, or undergo tilting or lower body negative pressure. The mechanisms which control these responses, e.g., the role of the central nervous system, are unclear.

  12. Cardiovascular responses of women to lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Frey, M. A. B.; Mathes, K. L.; Hoffler, G. W.

    1986-01-01

    The effects of lower body negative pressure (LBNP) on the cardiovascular response of 20 women between 23-43 years are evaluated. Calf circumference and cardiovascular data were recorded for women in the follicular and luteal phases of the menstrual cycle at -30, -40, and -50 mm Hg LBNP. The data reveal that the two menstrual phases did not cause differences in the way women respond to LBNP. It is observed that during LBNP calf circumference is enlarged; transthoracic impedance, and heart rate are increased; stroke volume, left ventricular ejection time, the Heather Index of contractility and systolic pressure, and cardiac output are reduced; and total peripheral resistance is elevated. The experimental data are compared to Montgomery et al. (1979). It is noted that the response of women to -50 mm Hg LBNP is similar to that of men; however, women adapt to stresses on the cardiovascular system with greater heart rate adjustments.

  13. Cardiovascular and thermal responses to SCUBA diving.

    PubMed

    Doubt, T J

    1996-05-01

    Recreational SCUBA diving exposes individuals to environmental stresses not often encountered in other types of activity. These stresses include increased ambient pressure, raised partial pressure of O(2), increased resistance to movement, added weight and drag of diving equipment, cold stress, and a higher breathing resistance. One means to understand how such stresses affect a diver is to employ the stress-strain-adaptive response model. Physiologic adaptations, like an increase in VO(2) in response to cold stress, will minimize the strain placed on thermal balance. Nonphysiologic adaptive responses include those behavioral and equipment interventions that isolate the diver from a particular stress. Self-contained underwater breathing apparatus (SCUBA) isolates the diver from the inability to extract O(2) from the water; dive garments minimize the stress of cold water immersion. This review will focus on cardiorespiratory and thermal responses to SCUBA diving, using the stress-strain-adaptive response model to illustrate the interaction between diver and environment. Some responses like hyperventilation, cardiac arrhythmias, or cold injury due to vasoconstriction are not considered adaptive but are realistic possibilities in diving environments.

  14. CARDIOVASCULAR RESPONSES TO ULTRAFINE CARBON PARTICLE EXPOSURES IN RATS

    EPA Science Inventory

    TD-02-042 (U. KODAVANTI) GPRA # 10108

    Cardiovascular Responses to Ultrafine Carbon Particle Exposures in Rats.
    V. Harder1, B. Lentner1, A. Ziesenis1, E. Karg1, L. Ruprecht1, U. Kodavanti2, A. Stampfl3, J. Heyder1, H. Schulz1
    GSF- Institute for Inhalation Biology1, I...

  15. CARDIOVASCULAR RESPONSES TO WALKING IN PATIENTS WITH PERIPHERAL ARTERY DISEASE

    PubMed Central

    Ritti-Dias, Raphael Mendes; Meneses, Annelise Lins; Parker, Donald E.; Montgomery, Polly S.; Khurana, Aman; Gardner, Andrew W.

    2013-01-01

    Purposes To assess the cardiovascular responses during constant load walking and to identify predictors of this response in peripheral artery disease (PAD) patients. Methods Seventy-nine patients with PAD performed a constant load treadmill test (2 mph, 0% grade). During the test, systolic blood pressure (BP), diastolic BP, and heart rate (HR) were obtained at the fourth minute to the last minute of exercise. Patients were also characterized on demographic measures, cardiovascular risk factors, baseline exercise performance and vascular measures. Results During constant load walking, there was a significant increase (p<0.01) in systolic BP (+12 ± 10 mmHg), diastolic BP (+6 ± 9 mmHg), and HR (+5 ± 5 bpm). The HR responses was negatively correlated with ischemic window (r= −0.23; p<0.05), expressed as an area under the curve of the resting ankle systolic BP and its recovery from maximal graded treadmill test, and positively correlated with the HR during the first minute of recovery from maximal graded treadmill test (r= 0.27; p<0.05). The increase in cardiovascular variables during constant load walking was greater in subjects with higher body mass index and in men (p<0.05). Conclusion Patients with PAD had an increased cardiovascular response during constant load walking, and these responses were greater in obese patients and in men. The clinical implication is that PAD patients engaged in walking training programs, particularly men and those with obesity, require frequent assessment of cardiovascular parameters to avoid exaggerated increases in BP and HR during constant load walking. PMID:21502888

  16. Cardiovascular Response Patterns to Sympathetic Stimulation by Central Hypovolemia.

    PubMed

    Bronzwaer, Anne-Sophie G T; Verbree, Jasper; Stok, Wim J; van Buchem, Mark A; Daemen, Mat J A P; van Osch, Matthias J P; van Lieshout, Johannes J

    2016-01-01

    In healthy subjects, variation in cardiovascular responses to sympathetic stimulation evoked by submaximal lower body negative pressure (LBNP) is considerable. This study addressed the question whether inter-subject variation in cardiovascular responses coincides with consistent and reproducible responses in an individual subject. In 10 healthy subjects (5 female, median age 22 years), continuous hemodynamic parameters (finger plethysmography; Nexfin, Edwards Lifesciences), and time-domain baroreflex sensitivity (BRS) were quantified during three consecutive 5-min runs of LBNP at -50 mmHg. The protocol was repeated after 1 week to establish intra-subject reproducibility. In response to LBNP, 5 subjects (3 females) showed a prominent increase in heart rate (HR; 54 ± 14%, p = 0.001) with no change in total peripheral resistance (TPR; p = 0.25) whereas the other 5 subjects (2 females) demonstrated a significant rise in TPR (7 ± 3%, p = 0.017) with a moderate increase in HR (21 ± 9%, p = 0.004). These different reflex responses coincided with differences in resting BRS (22 ± 8 vs. 11 ± 3 ms/mmHg, p = 0.049) and resting HR (57 ± 8 vs. 71 ± 12 bpm, p = 0.047) and were highly reproducible over time. In conclusion, we found distinct cardiovascular response patterns to sympathetic stimulation by LBNP in young healthy individuals. These patterns of preferential autonomic blood pressure control appeared related to resting cardiac BRS and HR and were consistent over time. PMID:27378944

  17. Cardiovascular Response Patterns to Sympathetic Stimulation by Central Hypovolemia

    PubMed Central

    Bronzwaer, Anne-Sophie G. T.; Verbree, Jasper; Stok, Wim J.; van Buchem, Mark A.; Daemen, Mat J. A. P.; van Osch, Matthias J. P.; van Lieshout, Johannes. J.

    2016-01-01

    In healthy subjects, variation in cardiovascular responses to sympathetic stimulation evoked by submaximal lower body negative pressure (LBNP) is considerable. This study addressed the question whether inter-subject variation in cardiovascular responses coincides with consistent and reproducible responses in an individual subject. In 10 healthy subjects (5 female, median age 22 years), continuous hemodynamic parameters (finger plethysmography; Nexfin, Edwards Lifesciences), and time-domain baroreflex sensitivity (BRS) were quantified during three consecutive 5-min runs of LBNP at −50 mmHg. The protocol was repeated after 1 week to establish intra-subject reproducibility. In response to LBNP, 5 subjects (3 females) showed a prominent increase in heart rate (HR; 54 ± 14%, p = 0.001) with no change in total peripheral resistance (TPR; p = 0.25) whereas the other 5 subjects (2 females) demonstrated a significant rise in TPR (7 ± 3%, p = 0.017) with a moderate increase in HR (21 ± 9%, p = 0.004). These different reflex responses coincided with differences in resting BRS (22 ± 8 vs. 11 ± 3 ms/mmHg, p = 0.049) and resting HR (57 ± 8 vs. 71 ± 12 bpm, p = 0.047) and were highly reproducible over time. In conclusion, we found distinct cardiovascular response patterns to sympathetic stimulation by LBNP in young healthy individuals. These patterns of preferential autonomic blood pressure control appeared related to resting cardiac BRS and HR and were consistent over time. PMID:27378944

  18. Cardiovascular disease management through restrained inflammatory responses.

    PubMed

    Jabir, Nasimudeen R; Tabrez, Shams

    2016-01-01

    Cardio vascular disease (CVD) is the end result of the accumulation of atheromatous plaques within the walls of the coronary arteries and remains the leading cause of death worldwide. Vascular inflammation and associated ongoing inflammatory responses have been considered as the critical culprits in the pathogenesis of CVD. Moreover, the activation of inflammatory pathways is not confined to coronary lesions only but involves the activation of neutrophils, monocytes and lymphocytes in peripheral blood. In view of high mortality rate associated with this devastated disease, it is essential that CVD and related complications should be taken care off at its earliest. To achieve that goal, some inflammatory mediators could be potentially targeted. In the current article, we will highlight targeting some inflammatory mediators viz. IL-1, IL-6, TNF-α etc for CVD management. As far as our knowledge goes, we are for the first time reporting the targeting inflammatory mediators especially IL-1, IL-6 and TNF-α together in a single article. Based on our review, we believe that scientific community will come up with certain anti-inflammatory agents against atherosclerosis in near future and hopefully that will be used for the successful management of CVD patients.

  19. Cardiovascular response to dynamic aerobic exercise: a mathematical model.

    PubMed

    Magosso, E; Ursino, M

    2002-11-01

    An original mathematical model of the cardiovascular response to dynamic exercise is presented. It includes the pulsating heart, the pulmonary and systemic circulation, a separate description of the vascular bed in active tissues, the local metabolic vasodilation in these tissues and the mechanical effects of muscular contractions on venous return. Moreover, the model provides a description of the ventilatory response to exercise and various neural regulatory mechanisms working on cardiovascular parameters. These mechanisms embrace the so-called central command, the arterial baroreflex and the lung inflation reflex. All parameters in the model have been given in accordance with physiological data from the literature. In this work, the model has been used to simulate the steady-state value of the main cardiorespiratory quantities at different levels of aerobic exercise and the temporal pattern in the transient phase from rest to moderate exercise. Results suggest that, with suitable parameter values the model is able accurately to simulate the cardiorespiratory response in the overall range of aerobic exercise. This response is characterised by a moderate hypertension (10-30%) and by a conspicuous increase in systemic conductance (80-130%), heart rate (64-150%) and cardiac output (100-200%). The transient pattern exhibits three distinct phases (lasting approximately 5s, 15s and 2 min), that reflect the temporal heterogeneity of the mechanisms involved. The model may be useful to improve understanding of exercise physiology and as an educational tool to analyse the complexity of cardiovascular and respiratory regulation.

  20. Cardiovascular response to dynamic aerobic exercise: a mathematical model.

    PubMed

    Magosso, E; Ursino, M

    2002-11-01

    An original mathematical model of the cardiovascular response to dynamic exercise is presented. It includes the pulsating heart, the pulmonary and systemic circulation, a separate description of the vascular bed in active tissues, the local metabolic vasodilation in these tissues and the mechanical effects of muscular contractions on venous return. Moreover, the model provides a description of the ventilatory response to exercise and various neural regulatory mechanisms working on cardiovascular parameters. These mechanisms embrace the so-called central command, the arterial baroreflex and the lung inflation reflex. All parameters in the model have been given in accordance with physiological data from the literature. In this work, the model has been used to simulate the steady-state value of the main cardiorespiratory quantities at different levels of aerobic exercise and the temporal pattern in the transient phase from rest to moderate exercise. Results suggest that, with suitable parameter values the model is able accurately to simulate the cardiorespiratory response in the overall range of aerobic exercise. This response is characterised by a moderate hypertension (10-30%) and by a conspicuous increase in systemic conductance (80-130%), heart rate (64-150%) and cardiac output (100-200%). The transient pattern exhibits three distinct phases (lasting approximately 5s, 15s and 2 min), that reflect the temporal heterogeneity of the mechanisms involved. The model may be useful to improve understanding of exercise physiology and as an educational tool to analyse the complexity of cardiovascular and respiratory regulation. PMID:12507317

  1. Role of arterial baroreceptors in mediating cardiovascular response to exercise

    NASA Technical Reports Server (NTRS)

    Mcritchie, R. J.; Vatner, S. F.; Patrick, T. A.; Braunwald, E.; Boettcher, D.; Heyndrickx, G. R.

    1976-01-01

    Experiments were conducted to define the role of the major arterial baroreceptors during moderately severe exercise by comparing the responses of untethered conscious dogs instrumented for the measurement of aortic pressure and cardiac output with those of dogs with total arterial baroreceptor denervation. The reflex heart rate responses to intravenous bolus doses of methoxamine were also examined in intact animals, both at rest and during exercise. Methoxamine is found to cause striking bradycardia at rest, but little bradycardia during exercise. Experimental findings suggest that the arterial baroreceptor reflex is normally inhibited during severe exercise and therefore plays little role in modulating the cardiovascular response to exercise.

  2. Cardiovascular

    NASA Video Gallery

    Overview of Cardiovascular research which addresses risks of space flight, including adaptive changes to the cephalad fluid shift (such as reduced circulating blood volume), potential for heart rhy...

  3. Task difficulty, cardiovascular response, and the magnitude of goal valence.

    PubMed

    Wright, R A; Contrada, R J; Patane, M J

    1986-10-01

    Sixty-four young women expected to perform an easy, moderately difficult, or extremely difficult memory task with the opportunity to earn a small incentive for good performance. Cardiovascular (heart rate, systolic and diastolic blood pressure) and subjective measures were taken immediately prior to task performance. Both systolic blood pressure (SBP) responses and ratings of goal attractiveness were nonmonotonically related to expected task difficulty, with the most pronounced SBP elevations and highest goal attractiveness in the moderately difficult task condition. Product-moment correlations among cardiovascular response measures revealed a strong positive association between systolic and diastolic pressure (but not heart rate) change in the easy condition, positive relationships among all measures in the moderately difficult condition, and no significant correlations in the extremely difficult condition. Subjective measures of arousal were not affected by the task difficulty manipulation. Principal findings are discussed in terms of a theoretical model proposed by Brehm (1979) that states that motivation varies as a nonmonotonic function of the difficulty of goal attainment. Intercorrelations among cardiovascular response variables are considered in terms of their possible indication of the mechanisms underlying blood pressure changes associated with variations in motivation. PMID:3783427

  4. Cardiovascular responses to water drinking: does osmolality play a role?

    PubMed

    Brown, Clive M; Barberini, Luc; Dulloo, Abdul G; Montani, Jean-Pierre

    2005-12-01

    Water drinking activates the autonomic nervous system and induces acute hemodynamic changes. The actual stimulus for these effects is undetermined but might be related to either gastric distension or to osmotic factors. In the present study, we tested whether the cardiovascular responses to water drinking are related to water's relative hypoosmolality. Therefore, we compared the cardiovascular effects of a water drink (7.5 ml/kg body wt) with an identical volume of a physiological (0.9%) saline solution in nine healthy subjects (6 male, 3 female, aged 26 +/- 2 years), while continuously monitoring beat-to-beat blood pressure (finger plethysmography), cardiac intervals (electrocardiography), and cardiac output (thoracic impedance). Total peripheral resistance was calculated as mean blood pressure/cardiac output. Cardiac interval variability (high-frequency power) was assessed by spectral analysis as an index of cardiac vagal tone. Baroreceptor sensitivity was evaluated using the sequence technique. Drinking water, but not saline, decreased heart rate (P = 0.01) and increased total peripheral resistance (P < 0.01), high-frequency cardiac interval variability (P = 0.03), and baroreceptor sensitivity (P = 0.01). Neither water nor saline substantially increased blood pressure. These responses suggest that water drinking simultaneously increases sympathetic vasoconstrictor activity and cardiac vagal tone. That these effects were absent after drinking physiological saline indicate that the cardiovascular responses to water drinking are influenced by its hypoosmotic properties.

  5. Race and blood pressure status influences cardiovascular responses to challenge.

    PubMed

    Saab, P G; Tischenkel, N; Spitzer, S B; Gellman, M D; Pasin, R D; Schneiderman, N

    1991-03-01

    The influence of race and blood pressure status on cardiovascular responses to three challenges (interview, video game and cold pressor) was investigated in 50 healthy normotensive and 30 unmedicated mild-to-moderate hypertensive black and white men, aged 25-44 years old. Group differences were obtained for two tasks. The interview evoked race and blood pressure status differences: higher heart rate responses were elicited from normotensives compared with hypertensives and larger diastolic blood pressure (DBP) responses were elicited from whites compared with blacks. For the video game, black hypertensives displayed larger DBP responses than white hypertensives and greater systolic blood pressure and DBP responses than black normotensives. The video game heart rate response of white normotensives exceeded that of black normotensives and white hypertensives. These findings suggest that cardiovascular responses to challenge are affected by race and blood pressure status. The blood pressure hyperresponsiveness of black hypertensives compared with black normotensives to a psychological challenge (video game) provides generality to previous research conducted only on whites. PMID:1851788

  6. Differential cardiovascular responses to stressors in hypertensive and normotensive rats.

    PubMed

    McDougall, Stuart J; Lawrence, Andrew J; Widdop, Robert E

    2005-01-01

    The aim of this study was to determine to what extent stress-induced cardiovascular responses depend upon rat strain and/or stressor. Spontaneously hypertensive rats (SHRs), Wistar-Kyoto rats (WKYs) and Sprague-Dawley (SD) rats were implanted with telemetry probes in order to measure heart rate and blood pressure changes when exposed to a stressor. The stress protocols employed included handling, air-jet and restraint, where each stressor was repeated over 10 consecutive days. In addition, a heterologous protocol was established whereby the experimental groups having experienced 10 days of air-jet stress were then immediately exposed to 10 consecutive days of restraint. Each stressor caused graded tachycardic and pressor responses in all strains. For all strains, the magnitude and duration of heart rate and blood pressure increases were greatest in the restraint-based protocols while handling and air-jet caused submaximal changes. A comparison between strains indicated that SHRs exhibited prolonged pressor responses to each of the stressor types tested as compared to the normotensive strains. In addition, repeated exposure over 10 days to handling and air-jet in SHRs caused tachycardic and/or pressor responses to adapt to 'normotensive-like' levels. Heterologous restraint stress caused sensitization of cardiovascular responses upon first exposure, predominantly in normotensive strains. Collectively these data show that the magnitude and duration of the tachycardia and pressor responses evoked by the stressors were different within the strains and were also modified by prior experience. In addition, the cardiovascular profiles presented in this study demonstrate that, within each strain, the heart rate response during stress is graded according to the type of stressor encountered.

  7. Autonomic and cardiovascular responses to chemoreflex stress in apnoea divers.

    PubMed

    Steinback, Craig D; Breskovic, Toni; Banic, Ivana; Dujic, Zeljko; Shoemaker, J Kevin

    2010-08-25

    Sleep apnoea, with repeated periods of hypoxia, results in cardiovascular morbidity and concomitant autonomic dysregulation. Trained apnoea divers also perform prolonged apnoeas accompanied by large lung volumes, large reductions in cardiac output and severe hypoxia and hypercapnia. We tested the hypothesis that apnoea training would be associated with decreased cardiovagal and sympathetic baroreflex gains and reduced respiratory modulation of muscle sympathetic nerve activity (MSNA; microneurography). Six trained divers and six controls were studied at rest and during asphyxic rebreathing. Despite an elevated resting heart rate (70+/-14 vs. 56+/-10 bpm; p=0.038), divers had a similar cardiovagal baroreflex gain (-1.22+/-0.47 beats/mmHg) as controls (-1.29+/-0.61; NS). Similarly, though MSNA burst frequency was slightly higher in divers at rest (16+/-4 bursts/min vs. 10+/-5 bursts/min, p=0.03) there was no difference in baseline burst incidence, sympathetic baroreflex gain (-3.8+/-2.1%/mmHg vs. -4.7+/-1.7%/mmHg) or respiratory modulation of MSNA between groups. Resting total peripheral resistance (11.9+/-2.6 vs. 12.3+/-2.2 mmHg/L/min) and pulse wave velocity (5.82+/-0.55 vs. 6.10+/-0.51 m/s) also were similar between divers and controls, respectively. Further, the sympathetic response to asphyxic rebreathing was not different between controls and divers (-1.70+/-1.07 vs. -1.74+/-0.84 a.u./% desaturation). Thus, these data suggest that, unlike patients with sleep apnoea, apnoea training in otherwise healthy individuals does not produce detectable autonomic dysregulation or maladaption.

  8. Cardiovascular and respiratory responses evoked from the posterior cerebellar cortex and fastigial nucleus in the cat.

    PubMed Central

    Bradley, D J; Pascoe, J P; Paton, J F; Spyer, K M

    1987-01-01

    1. In both anaesthetized and decerebrate cats the cerebellar cortex (lobules VI, VII, VIII, IX and X) and the fastigial nucleus (f.n.) have been stimulated electrically, and chemically, while recording changes in phrenic nerve discharge, heart rate, arterial blood pressure and renal and femoral blood flow. 2. Stimulation of lobules VI, VII, VIII and Xb failed to elicit any cardiovascular or respiratory changes. Activation of lobule IX (the uvula), and in some preparations sub-lobule Xa, evoked cardiovascular and respiratory responses consistently. In the anaesthetized cat, electrical stimulation of the uvula evoked apnoea, a small bradycardia and a depressor response associated with vasodilatation in the hindlimb vascular bed. In contrast, stimulation in an equivalent region in a decerebrate preparation elicited an apneustic discharge, a pronounced tachycardia and a rise in arterial pressure with vasoconstriction in both renal and femoral vascular beds. In both the anaesthetized and decerebrate animals the pattern of response elicited by chemical activation was identical to that seen with electrical stimulation. 3. Electrical, or chemical, stimulation after administration of anaesthetic to the decerebrate cat then evoked an identical pattern of response to that seen in the 'intact' anaesthetized animal. This evidence suggests that the reversal in the pattern of the response in an effect of the anaesthetic agent and not the decerebration itself. 4. The only area of the f.n. to produce cardiovascular effects was the rostral region. Electrical stimulation of the rostral f.n. in both anaesthetized and decerebrate preparations inhibited central inspiratory activity and evoked tachycardia, along with a pressor response associated with vasoconstriction in both renal and femoral vascular beds. In contrast, chemical excitation of those sites in the rostral f.n. shown previously to produce pronounced cardiovascular and respiratory changes failed to elicit any changes in the

  9. Sleep duration and cardiovascular responses to stress in undergraduate men.

    PubMed

    Mezick, Elizabeth J; Matthews, Karen A; Hall, Martica H; Richard Jennings, J; Kamarck, Thomas W

    2014-01-01

    Short sleep has been related to incident cardiovascular disease, but physiological mechanisms accounting for this relationship are largely unknown. This study examines sleep duration and cardiovascular stress responses in 79 healthy, young men. Sleep duration was assessed by wrist actigraphy for seven nights. Participants then completed a series of laboratory stress tasks while heart rate and blood pressure were monitored. Shorter total sleep time was related to a greater reduction in high-frequency heart rate variability during stress tasks, and to prolonged elevations in heart rate and diastolic pressure following tasks. Associations were independent of age, race, body mass index, caffeine intake, and smoking status. In sum, healthy young men with shorter actigraphy-assessed sleep exhibit less cardiac vagal activity, and poorer heart rate and diastolic blood pressure recovery, upon encountering stressful stimuli, than those with longer sleep. PMID:24016263

  10. Comparing Visible and Invisible Social Support: Non-evaluative Support Buffers Cardiovascular Responses to Stress.

    PubMed

    Kirsch, Julie A; Lehman, Barbara J

    2015-12-01

    Previous research suggests that in contrast to invisible social support, visible social support produces exaggerated negative emotional responses. Drawing on work by Bolger and colleagues, this study disentangled social support visibility from negative social evaluation in an examination of the effects of social support on negative emotions and cardiovascular responses. As part of an anticipatory speech task, 73 female participants were randomly assigned to receive no social support, invisible social support, non-confounded visible social support or visible social support as delivered in a 2007 study by Bolger and Amarel. Twelve readings, each for systolic blood pressure, diastolic blood pressure and heart rate were taken at 5-min intervals throughout the periods of baseline, reactivity and recovery. Cardiovascular outcomes were tested by incorporating a series of theoretically driven planned contrasts into tests of stress reactivity conducted through piecewise growth curve modelling. Linear and quadratic trends established cardiovascular reactivity to the task. Further, in comparison to the control and replication conditions, the non-confounded visible and invisible social support conditions attenuated cardiovascular reactivity over time. Pre- and post-speech negative emotional responses were not affected by the social support manipulations. These results suggest that appropriately delivered visible social support may be as beneficial as invisible social support.

  11. Renal Function and Cardiovascular Response to Mental Stress

    PubMed Central

    Seliger, Stephen L.; Katzel, Leslie I.; Fink, Jeffrey C.; Weir, Matthew R.; Waldstein, Shari R.

    2008-01-01

    Background/Aims Cardiovascular reactivity (CVR), defined as an exaggerated hemodynamic response to mental stress, is a putative vascular risk factor and may reflect sympathetic hyperactivity. Chronic kidney disease (CKD) is also associated with sympathetic hyperactivity and vascular risk, but its relationship with CVR is unknown. Methods CVR was assessed in 107 individuals without overt cardiovascular disease or diabetes. Blood pressure and heart rate responses were elicited by three experimental tasks designed to evoke mental stress. Glomerular filtration rate (eGFR) was estimated using the MDRD formula. General linear models estimated the association between renal function and CVR, adjusting for potential confounders. Results Mean age was 66 years and 11% had eGFR of <60 ml/min/1.73 m2. After multivariate adjustment, a low eGFR was associated with a greater stress response of systolic blood pressure, heart rate, and pulse pressure. Associations were only partially attenuated after adjustment for lipids and glucose tolerance. When considered as a continuous variable, lower eGFR was associated with a greater blood pressure response after adjustment for glycemia. Conclusion Although there were relatively few participants with CKD, these results suggest a relationship between CKD and greater CVR. Further investigation is warranted into factors that mediate this relationship and potential clinical consequences of this exaggerated response to stress in CKD. PMID:18025779

  12. Failure to produce response variability with reinforcement

    PubMed Central

    Schwartz, Barry

    1982-01-01

    Two experiments attempted to train pigeons to produce variable response sequences. In the first, naive pigeons were exposed to a procedure requiring four pecks on each of two keys in any order, with a reinforcer delivered only if a given sequence was different from the preceding one. In the second experiment, the same pigeons were exposed to this procedure after having been trained successfully to alternate between two specific response sequences. In neither case did any pigeon produce more than a few different sequences or obtain more than 50% of the possible reinforcers. Stereotyped sequences developed even though stereotypy was not reinforced. It is suggested that reinforcers have both hedonic and informative properties and that the hedonic properties are responsible for sterotyped repetition of reinforced responses, even when stereotypy is negatively related to reinforcer delivery. PMID:16812263

  13. Cardiovascular responses to glucagon - Physiologic measurement by external recordings.

    NASA Technical Reports Server (NTRS)

    Byrne, M. J.; Pigott, V.; Spodick, D. H.

    1972-01-01

    Assessment by noninvasive polygraphic techniques of the cardiovascular responses of normal subjects to intravenous injections of glucagon and glucagon diluent. A blinding procedure which eliminated observer bias was used during the reading of tracings. Analysis of group results showed that glucagon provoked uniformly significant changes, including increase in heart rate, blood pressure, pressure-rate product, and ejection time index, and decrease in prejection period, mechanical and electromechanical systole, left ventricular ejection time, and the ratio PEP/LVET. The principal results correlated well with those of previous studies of the hemodynamic effects of glucagon.

  14. The cardiovascular response to passive movement is joint dependent.

    PubMed

    Burns, Keith J; Pollock, Brandon S; McDaniel, John

    2016-03-01

    The cardiovascular responses to passive limb movement (PLM) at the knee are well established, however, responses to PLM at other joints involving smaller muscle volume are unknown. To compare the cardiovascular responses to passive movement at other joints, 10 participants underwent a PLM protocol in which the wrist, elbow, ankle, and knee joints were passively extended and flexed at 1 Hz for 1 min. Heart rate (HR), mean arterial blood pressure (MAP), and arterial blood flow to that limb segment (BF) were measured and vascular conductance (VC) was calculated for a 30-sec baseline period and for 3-sec intervals throughout PLM protocols. PLM of the knee and elbow resulted in significant increases in BF and VC from baseline values with peak values 180% (P < 0.001) greater than baseline. PLM of the elbow resulted in significant increases in BF and VC from baseline values with peak values 109% and 115% (P < 0.001) greater than baseline, respectively. No changes in BF and VC were observed in the ankle and wrist. Furthermore, the greater increase in blood flow per limb segment volume in the thigh and upper arm (62.8 ± 36.5 and 55.5 ± 30.3 mL min(-1) L(-1), respectively) compared to the forearm and lower leg (23.6 ± 16.7 and 19.1 ± 10.3 mL min(-1) L(-1), respectively) indicates the limb volume is not solely responsible for the differences in the hyperemic responses. These data indicate that the use of PLM to assess vascular function or as a rehabilitation modality to maintain vascular health may be most appropriate for the muscles that span the elbow and knee.

  15. Increased cardiovascular response to static contraction of larger muscle groups.

    PubMed

    Seals, D R; Washburn, R A; Hanson, P G; Painter, P L; Nagle, F J

    1983-02-01

    The purpose of this study was to investigate the influence of the size of the active muscle mass on the cardiovascular response to static contraction. Twelve male subjects performed one-arm handgrip (HG), two-leg extension (LE), and a "dead-lift" maneuver (DL) in a randomly assigned order for 3 min at 30% of maximal voluntary contraction. O2 uptake (VO2), heart rate (HR), and mean intra-arterial blood pressure (MABP) were measured at rest and, in addition to absolute tension exerted, throughout contraction. There was a direct relationship between the size of the active muscle mass and the magnitude of the increases in VO2, HR, and MABP, even though all contractions were performed at the same relative intensity. Tension, VO2, HR, and MABP increased progressively from HG to LE to DL. It was concluded that at the same percentage of maximal voluntary contraction, the magnitude of the cardiovascular response to isometric exercise is directly influenced by the size of the contracting muscle mass.

  16. Cardiovascular response to static contraction in borderline hypertension.

    PubMed

    Seals, D R; Hanson, P G; Washburn, R A; Painter, P L; Ward, A; Nagle, F J

    1985-06-01

    Nine young males with borderline hypertension (BH) (mean age +/- SD, 25 +/- 5 yr) and 13 young male normotensive controls (NT) (24 +/- 3 yr) were studied to determine their cardiovascular responses to small and large muscle static contractions. The subjects performed one-arm handgrip and two-leg extension in a randomly assigned order for 3 min at 30% of maximal voluntary contraction. Mean intra-arterial blood pressure (MABP), heart rate (HR), and tension were measured throughout the contractions. Borderline hypertensive patients had a higher MABP at rest (p less than 0.005) and at the end of both types of static contractions (p less than 0.05). The average increases in MABP from rest to the end of exercise (delta MABP) were slightly greater for the BH patients (6 mmHg), but these differences were not significant (p greater than 0.1). However, a greater percentage of BH patients were hyperreactive to handgrip (delta BP greater than 35 mmHg) and leg extension (delta BP greater than 40 mmHg) when compared to controls. These data indicate that, in general, young men with borderline hypertension demonstrate normal cardiovascular regulation in response to static contraction, but that a portion of this population may be hyperreactive to this type of circulatory stress.

  17. Type A behavior, personality hardiness, and cardiovascular responses to stress.

    PubMed

    Contrada, R J

    1989-11-01

    Type A behavior and hardiness were examined as predictors of cardiovascular responses to stress in 68 male undergraduates. Systolic and diastolic blood pressure (SBP and DBP) and heart rate were monitored while subjects performed a difficult mirror-tracing task. Type A assessments based on the Structured Interview, but not those based on the Jenkins Activity Survey, were associated with significantly enhanced SBP and DBP elevations. Hardiness was associated with significantly reduced DBP responsiveness. In addition, a significant interaction indicated that the Type B-high hardiness group showed the least DBP reactivity. A near-significant interaction (p = .06) suggested that Type B-high hardiness subjects also reported the least anger. Further exploration of the data indicated that the challenge component of hardiness accounted for its relationship to DBP reactivity. These results have implications both for the psychophysiologic study of Type A behavior and for understanding the health-promoting effects of hardiness.

  18. Physical fitness and cardiovascular response to lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Raven, P. B.; Rohm-Young, D.; Blomqvist, C. G.

    1984-01-01

    Klein et al. (1977) have questioned the concept of endurance training as an appropriate means of preparing for prolonged space flights. Their opinion was mainly based on reports of endurance athletes who had a decreased tolerance to orthostatic or gravitational stress induced by lower body negative pressure (LBNP), upright tilt, or whole body water immersion. The present investigation had the objective to determine if the hemodynamic response to LBNP is different between a high and average fit group of subjects. In addition, the discrete aspect of cardiovascular function which had been altered by chronic training was to be identified. On the basis of the results of experiments conducted with 14 young male volunteers, it is concluded that the reflex response to central hypovolemia is altered by endurance exercise training.

  19. Reproducibility of exercise-induced modulation of cardiovascular responses to cold stress.

    PubMed

    Rashed, H M; Leventhal, G; Madu, E C; Reddy, R; Cardoso, S

    1997-04-01

    The modulation of cardiovascular responses to the cold pressor test (CPT) as produced by exercise was studied in 13 volunteers. The reproducibility of the measurements selected for the study, i.e. heart rate (HR), blood pressure (BP), blood flow (BF) and skin temperature (ST), was investigated through repeat experiments in the fall of 1994 and the winter of 1995. HR was monitored before, during and after a 10-min period of bicycling at 70% of reserve HR. BP, cutaneous BF and ST were measured before and after exercise. Two CPTs (hand into ice-cold water for 1 min) were performed: one preceding exercise and another at 3 min after exercise. The results obtained allow us to conclude that in non-hypertensive volunteers (1) the pronounced cardiovascular responses (ST, BF and BP) induced by CPT are reproducible (p > 0.2) when compared to basal level values and (2) cardiovascular responses to cold stress are significantly attenuated by exercise (p < 0.03). Our study, therefore, supports and validates the use of our coupled exercise-CPT method in ongoing epidemiological studies attempting to identify individuals at risk for the development of hypertension as well as those most likely to benefit from preventative exercise programs.

  20. Melatonin modulates the fetal cardiovascular defense response to acute hypoxia.

    PubMed

    Thakor, Avnesh S; Allison, Beth J; Niu, Youguo; Botting, Kimberley J; Serón-Ferré, Maria; Herrera, Emilio A; Giussani, Dino A

    2015-08-01

    Experimental studies in animal models supporting protective effects on the fetus of melatonin in adverse pregnancy have prompted clinical trials in human pregnancy complicated by fetal growth restriction. However, the effects of melatonin on the fetal defense to acute hypoxia, such as that which may occur during labor, remain unknown. This translational study tested the hypothesis, in vivo, that melatonin modulates the fetal cardiometabolic defense responses to acute hypoxia in chronically instrumented late gestation fetal sheep via alterations in fetal nitric oxide (NO) bioavailability. Under anesthesia, 6 fetal sheep at 0.85 gestation were instrumented with vascular catheters and a Transonic flow probe around a femoral artery. Five days later, fetuses were exposed to acute hypoxia with or without melatonin treatment. Fetal blood was taken to determine blood gas and metabolic status and plasma catecholamine concentrations. Hypoxia during melatonin treatment was repeated during in vivo NO blockade with the NO clamp. This technique permits blockade of de novo synthesis of NO while compensating for the tonic production of the gas, thereby maintaining basal cardiovascular function. Melatonin suppressed the redistribution of blood flow away from peripheral circulations and the glycemic and plasma catecholamine responses to acute hypoxia. These are important components of the fetal brain sparing response to acute hypoxia. The effects of melatonin involved NO-dependent mechanisms as the responses were reverted by fetal treatment with the NO clamp. Melatonin modulates the in vivo fetal cardiometabolic responses to acute hypoxia by increasing NO bioavailability.

  1. Essential Hypertension: Cardiovascular Response to Breath Hold Combined with Exercise.

    PubMed

    Hoffmann, U; Urban, P; Koschate, J; Drescher, U; Pfister, R; Michels, G

    2015-07-01

    Essential hypertension (EH) is a widespread disease and might be prevalent in apnea divers and master athletes. Little is known about the influence of EH and the antihypertensive drugs (AHD) on cardiovascular reactions to combined breath hold (BH) and exercise. In this pilot study, healthy divers (HCON) were compared with treated hypertensive divers with regard to heart rate (HR) and mean blood-pressure (MAP) responses to BH, exercise and the combination of both. Ten subjects with EH and ten healthy divers were tested. 3 different 20 s stimuli were applied: BH combined with 30 W or 150 W and 150 W without BH. The time-charts during the stress intervals and during recovery were compared. Subjects treated with an angiotensin-converting enzyme (ACE) inhibitor showed higher changes for MAP values if breath hold was performed. HR responses were obviously changed if a β-blocker was part of the medication. One subject showed extreme MAP responses to all stimuli and conspicuous HR if BH was involved. The modulation of HR-/MAP-response in EH subjects depends on the mechanisms of antihypertensive agents. The combination of an ACE inhibitor and a β-blocker may give the best protection. It is recommended to include short apnea tests in the fitness-to-dive examination to individually predict potential endangerment. PMID:25875316

  2. Autonomic cardiovascular responses to smoke exposure in conscious rats

    SciTech Connect

    Nakamura, T.; Hayashida, Y. )

    1992-05-01

    Autonomic cardiovascular responses and the change in renal sympathetic nerve activity (RSNA) in response to smoke exposure were investigated in unrestrained conscious rats. Smoke exposure caused a prominent increase in RSNA (to 557.3 +/- 221.9% of the control level) and plasma norepinephrine (from 0.18 +/- 0.08 (control) to 0.66 +/- 0.22 ng/ml (at peak response of smoke exposure)), a slight increase in arterial blood pressure (from 89.6 +/- 3.3 to 103.6 +/- 3.8 mmHg), and marked bradycardia (from 386.6 +/- 12.8 to 231.3 +/- 20.6 beats/min). Respiratory rate in conscious rats was initially increased (from 1.6 +/- 0.1 to 6.1 +/- 0.3 breaths/s) but was decreased (to 0.9 +/- 0.1 breaths/s) at the peak phase of the cardiovascular responses to smoke inhalation. Blood gases and pH reflected these changes in respiratory rate to some extent. Sinoaortic denervation did not attenuate the bradycardia (from 402 +/- 17.5 to 255.8 +/- 16.2 beats/min) or increase in RSNA (to 413.4 +/- 74.9%) that occurred during smoke inhalation. Atropine sulfate abolished the bradycardic response (from 440.4 +/- 13.8 to 485.4 +/- 8.6 beats/min). Initial tachypnea was also observed in both sinoaortic denervated rats and atropine-treated rats. Anesthesia, induced by pentobarbital sodium (30 mg/kg iv) or alpha-chloralose (65 mg/kg iv), abolished the bradycardia, the increase in RSNA, and the change in respiratory rate caused by smoke exposure. Ablation of the olfactory lobes also greatly attenuated the smoke-induced increase in RSNA (to 150.9 +/- 22.9%), bradycardia (from 372.9 +/- 19.6 to 376.3 +/- 24.1 beats/min), and the respiratory change.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Divergent Associations of Antecedent- and Response-Focused Emotion Regulation Strategies with Midlife Cardiovascular Disease Risk

    PubMed Central

    Loucks, Eric B.; Buka, Stephen L.; Kubzansky, Laura D.

    2014-01-01

    Background It is not known whether various forms of emotion regulation are differentially related to cardiovascular disease risk. Purpose The purpose of this study is to assess whether antecedent and response-focused emotion regulation would have divergent associations with likelihood of developing cardiovascular disease. Methods Two emotion regulation strategies were examined: reappraisal (antecedent-focused) and suppression (response-focused). Cardiovascular disease risk was assessed with a validated Framingham algorithm that estimates the likelihood of developing CVD in 10 years. Associations were assessed among 373 adults via multiple linear regression. Pathways and gender-specific associations were also considered. Results One standard deviation increases in reappraisal and suppression were associated with 5.9 % lower and 10.0 % higher 10-year cardiovascular disease risk, respectively, in adjusted analyses. Conclusions Divergent associations of antecedent and response-focused emotion regulation with cardiovascular disease risk were observed. Effective emotion regulation may promote cardiovascular health. PMID:24570218

  4. Metabolic and Cardiovascular Response to Shallow Water Exercise in Young and Older Women.

    ERIC Educational Resources Information Center

    Campbell, Jennifer A.; D'Acquisto, Leo J.; D'Acquisto, Debra M.; Cline, Michael G.

    2003-01-01

    Compared the metabolic and cardiovascular responses of young and older women while performing shallow water exercise (SWE). Overall, SWE elicited metabolic and cardiovascular responses that met American College of Sports Medicine's guidelines for establishing health benefits. Older females self-selected a greater relative exercise intensity during…

  5. Computational modeling of cardiovascular response to orthostatic stress

    NASA Technical Reports Server (NTRS)

    Heldt, Thomas; Shim, Eun B.; Kamm, Roger D.; Mark, Roger G.

    2002-01-01

    The objective of this study is to develop a model of the cardiovascular system capable of simulating the short-term (< or = 5 min) transient and steady-state hemodynamic responses to head-up tilt and lower body negative pressure. The model consists of a closed-loop lumped-parameter representation of the circulation connected to set-point models of the arterial and cardiopulmonary baroreflexes. Model parameters are largely based on literature values. Model verification was performed by comparing the simulation output under baseline conditions and at different levels of orthostatic stress to sets of population-averaged hemodynamic data reported in the literature. On the basis of experimental evidence, we adjusted some model parameters to simulate experimental data. Orthostatic stress simulations are not statistically different from experimental data (two-sided test of significance with Bonferroni adjustment for multiple comparisons). Transient response characteristics of heart rate to tilt also compare well with reported data. A case study is presented on how the model is intended to be used in the future to investigate the effects of post-spaceflight orthostatic intolerance.

  6. Computational modeling of cardiovascular response to orthostatic stress.

    PubMed

    Heldt, Thomas; Shim, Eun B; Kamm, Roger D; Mark, Roger G

    2002-03-01

    The objective of this study is to develop a model of the cardiovascular system capable of simulating the short-term (< or = 5 min) transient and steady-state hemodynamic responses to head-up tilt and lower body negative pressure. The model consists of a closed-loop lumped-parameter representation of the circulation connected to set-point models of the arterial and cardiopulmonary baroreflexes. Model parameters are largely based on literature values. Model verification was performed by comparing the simulation output under baseline conditions and at different levels of orthostatic stress to sets of population-averaged hemodynamic data reported in the literature. On the basis of experimental evidence, we adjusted some model parameters to simulate experimental data. Orthostatic stress simulations are not statistically different from experimental data (two-sided test of significance with Bonferroni adjustment for multiple comparisons). Transient response characteristics of heart rate to tilt also compare well with reported data. A case study is presented on how the model is intended to be used in the future to investigate the effects of post-spaceflight orthostatic intolerance. PMID:11842064

  7. Adrenergic and vasopressinergic contributions to the cardiovascular response to acute hypoxaemia in the llama fetus

    PubMed Central

    Giussani, D A; Riquelme, R A; Sanhueza, E M; Hanson, M A; Blanco, C E; Llanos, A J

    1999-01-01

    The effects of fetal intravenous treatment with phentolamine or a vasopressinergic V1-receptor antagonist on the fetal cardiovascular responses to acute hypoxaemia in the llama were investigated. Six llama fetuses were surgically prepared between 60 and 70% of gestation under general halothane anaesthesia with vascular catheters and transit-time ultrasonic flow probes around a carotid artery and a femoral artery. At least 4 days after surgery all fetuses were subjected to a 3 h experiment: 1 h of normoxia, 1 h of hypoxaemia and 1 h of recovery while on slow i.v. infusion with saline. On separate days this experiment was repeated with fetal i.v. treatment with either phentolamine or a V1-receptor antagonist dissolved in saline. During saline infusion all llama fetuses responded to acute hypoxaemia with intense femoral vasoconstriction. Phentolamine during normoxia produced hypotension, tachycardia and vasodilatation in both the carotid and the femoral circulations. During hypoxaemia, fetuses treated with phentolamine did not elicit the pronounced femoral vasoconstriction and all died within 20 min of the onset of hypoxaemia. A V1-receptor antagonist produced a femoral vasodilatation during normoxia but did not affect the fetal cardiovascular responses to acute hypoxaemia. In conclusion, α-adrenergic and V1-vasopressinergic mechanisms contribute to a basal vasoconstrictor tone in the femoral circulation in the llama fetus. The enhanced femoral vasoconstriction during acute hypoxaemia in the llama fetus is not mediated by stimulation of V1-vasopressin receptors, but is dependent on α-adrenergic receptor stimulation. Such α-adrenergic efferent mechanisms are indispensable to fetal survival during hypoxaemia in the llama since their abolition leads to cardiovascular collapse and death. PMID:9925892

  8. Endothelial cell injury in cardiovascular surgery: the procoagulant response.

    PubMed

    Boyle, E M; Verrier, E D; Spiess, B D

    1996-11-01

    The vascular endothelium plays a critical role in the regulation of coagulation through the constitutive expression and release of anticoagulants and the inducible expression of procoagulant substances. Cardiopulmonary bypass dysregulates this process by activating endothelial cells, initially promoting bleeding and then thrombosis. Endothelial cell activation in response to circulating inflammatory mediators leads to the initiation of coagulation when tissue factor is expressed throughout the intravascular space. This results in the widespread consumption of coagulation factors. Additionally, there is a cardiopulmonary bypass-related qualitative platelet defect that is exacerbated by thrombocytopenia as platelets are consumed from the circulation by clot and adherence to the cardiopulmonary bypass circuit. Finally, cardiopulmonary bypass results in the endothelial release of plasminogen activators, which lead to an increase in systemic fibrinolysis. The diffuse generation of thrombin, driven by the inducible intravascular expression of tissue factor, plays a major role in all of these processes. Efforts to understand the critical role of the endothelium in coagulation may lead to novel therapies to prevent bleeding or thrombosis in cardiovascular surgery patients.

  9. Cardiovascular responses to microgravity - Adaptation, maladjustment, and countermeasures

    NASA Technical Reports Server (NTRS)

    Gaffney, F. Andrew

    1989-01-01

    Humans have worked in space for up to 237 days without significant inflight limitations, although major cardiovascular disability is seen following space flight of even a few days duration. Most of the cardiovascular research on microgravity deconditioning has been observational in character. Detailed studies of mechanisms and causes of postflight exercise intolerance, low blood pressure and fainting in astronauts and cosmonauts have not been done, despite almost 30 years of manned space flight. A review of possible mechanisms of postflight cardiovascular deconditioning and directions for study is provided.

  10. Earthworms produce phytochelatins in response to arsenic.

    PubMed

    Liebeke, Manuel; Garcia-Perez, Isabel; Anderson, Craig J; Lawlor, Alan J; Bennett, Mark H; Morris, Ceri A; Kille, Peter; Svendsen, Claus; Spurgeon, David J; Bundy, Jacob G

    2013-01-01

    Phytochelatins are small cysteine-rich non-ribosomal peptides that chelate soft metal and metalloid ions, such as cadmium and arsenic. They are widely produced by plants and microbes; phytochelatin synthase genes are also present in animal species from several different phyla, but there is still little known about whether these genes are functional in animals, and if so, whether they are metal-responsive. We analysed phytochelatin production by direct chemical analysis in Lumbricus rubellus earthworms exposed to arsenic for a 28 day period, and found that arsenic clearly induced phytochelatin production in a dose-dependent manner. It was necessary to measure the phytochelatin metabolite concentrations directly, as there was no upregulation of phytochelatin synthase gene expression after 28 days: phytochelatin synthesis appears not to be transcriptionally regulated in animals. A further untargetted metabolomic analysis also found changes in metabolites associated with the transsulfuration pathway, which channels sulfur flux from methionine for phytochelatin synthesis. There was no evidence of biological transformation of arsenic (e.g. into methylated species) as a result of laboratory arsenic exposure. Finally, we compared wild populations of earthworms sampled from the field, and found that both arsenic-contaminated and cadmium-contaminated mine site worms had elevated phytochelatin concentrations.

  11. Earthworms Produce phytochelatins in Response to Arsenic

    PubMed Central

    Lawlor, Alan J.; Bennett, Mark H.; Morris, Ceri A.; Kille, Peter; Svendsen, Claus; Spurgeon, David J.; Bundy, Jacob G.

    2013-01-01

    Phytochelatins are small cysteine-rich non-ribosomal peptides that chelate soft metal and metalloid ions, such as cadmium and arsenic. They are widely produced by plants and microbes; phytochelatin synthase genes are also present in animal species from several different phyla, but there is still little known about whether these genes are functional in animals, and if so, whether they are metal-responsive. We analysed phytochelatin production by direct chemical analysis in Lumbricus rubellus earthworms exposed to arsenic for a 28 day period, and found that arsenic clearly induced phytochelatin production in a dose-dependent manner. It was necessary to measure the phytochelatin metabolite concentrations directly, as there was no upregulation of phytochelatin synthase gene expression after 28 days: phytochelatin synthesis appears not to be transcriptionally regulated in animals. A further untargetted metabolomic analysis also found changes in metabolites associated with the transsulfuration pathway, which channels sulfur flux from methionine for phytochelatin synthesis. There was no evidence of biological transformation of arsenic (e.g. into methylated species) as a result of laboratory arsenic exposure. Finally, we compared wild populations of earthworms sampled from the field, and found that both arsenic-contaminated and cadmium-contaminated mine site worms had elevated phytochelatin concentrations. PMID:24278409

  12. Cardiovascular and neurohumoral responses to behavioral challenge as a function of race and sex.

    PubMed

    Tischenkel, N J; Saab, P G; Schneiderman, N; Nelesen, R A; Pasin, R D; Goldstein, D A; Spitzer, S B; Woo-Ming, R; Weidler, D J

    1989-01-01

    Cardiovascular and hormonal responses to a structured interview, an electronic video game, a cold pressor test, and exercise on a bicycle ergometer were assessed in eighty-three 25- to 44-year-old normotensive Black and White men and women. Blacks showed significantly greater diastolic blood pressure (DBP) responses than Whites during the cold pressor test, which were not accounted for by an increase in plasma catecholamines. Exercise produced reliably greater systolic blood pressure (SBP) increases in Black women than in Black men or White women. Men showed significantly greater SBP and DBP changes than women during the video game. These findings suggest that the pattern of physiological reactivity elicited by challenge is related to the race and sex of the subjects. PMID:2698349

  13. Cardiovascular responses to static exercise in distance runners and weight lifters

    NASA Technical Reports Server (NTRS)

    Longhurst, J. C.; Kelly, A. R.; Gonyea, W. J.; Mitchell, J. H.

    1980-01-01

    Three groups of athletes including long-distance runners, competitive and amateur weight lifters, and age- and sex-matched control subjects have been studied by hemodynamic and echocardiographic methods in order to determine the effect of the training programs on the cardiovascular response to static exercise. Blood pressure, heart rate, and double product data at rest and at fatigue suggest that competitive endurance (dynamic exercise) training alters the cardiovascular response to static exercise. In contrast to endurance exercise, weight lifting (static exercise) training does not alter the cardiovascular response to static exercise: weight lifters responded to static exercise in a manner very similar to that of the control subjects.

  14. Predictors of cardiovascular response to methamphetamine administration in methamphetamine-dependent individuals.

    PubMed

    Fleury, Gilles; De La Garza, Richard; Mahoney, James J; Evans, Sarah E; Newton, Thomas F

    2008-01-01

    The goal of the present investigation was to determine predictors of cardiovascular response to methamphetamine administrated in the laboratory. Heart rate (HR) and blood pressure (BP) were measured at baseline and at several time points following the administration of methamphetamine or saline placebo. One-way ANOVA was used to determine the differences between female and male subjects in their cardiovascular response. In male subjects, linear regression and one-way ANOVA were used to determine the influence of potential predictors on cardiovascular response, including age, weight, drug use indicators, concurrent use of other substances, route of administration, and race. Methamphetamine administration provoked significant increases in HR and BP, as compared to placebo. Female gender was associated with larger peak change in diastolic BP following administration. Baseline HR and BP were found to be strong predictors of cardiovascular response to methamphetamine administration in male subjects. Lifetime use and recent use of methamphetamine and nicotine did not predict cardiovascular response to methamphetamine. Recent alcohol use was associated with increased peak change in diastolic BP. Also, current use of cannabis was negatively correlated with peak HR change. Male cannabis users show lower peak change in HR as compared to non-cannabis users. As compared to methamphetamine smokers, intravenous users demonstrated higher peak change in diastolic BP following drug administration. Race did not have a significant effect on cardiovascular response. Taken together, these findings may help in the prevention and treatment of cardiovascular events in a population at high risk of premature morbidity and mortality.

  15. Predictors of cardiovascular response to methamphetamine administration in methamphetamine-dependent individuals.

    PubMed

    Fleury, Gilles; De La Garza, Richard; Mahoney, James J; Evans, Sarah E; Newton, Thomas F

    2008-01-01

    The goal of the present investigation was to determine predictors of cardiovascular response to methamphetamine administrated in the laboratory. Heart rate (HR) and blood pressure (BP) were measured at baseline and at several time points following the administration of methamphetamine or saline placebo. One-way ANOVA was used to determine the differences between female and male subjects in their cardiovascular response. In male subjects, linear regression and one-way ANOVA were used to determine the influence of potential predictors on cardiovascular response, including age, weight, drug use indicators, concurrent use of other substances, route of administration, and race. Methamphetamine administration provoked significant increases in HR and BP, as compared to placebo. Female gender was associated with larger peak change in diastolic BP following administration. Baseline HR and BP were found to be strong predictors of cardiovascular response to methamphetamine administration in male subjects. Lifetime use and recent use of methamphetamine and nicotine did not predict cardiovascular response to methamphetamine. Recent alcohol use was associated with increased peak change in diastolic BP. Also, current use of cannabis was negatively correlated with peak HR change. Male cannabis users show lower peak change in HR as compared to non-cannabis users. As compared to methamphetamine smokers, intravenous users demonstrated higher peak change in diastolic BP following drug administration. Race did not have a significant effect on cardiovascular response. Taken together, these findings may help in the prevention and treatment of cardiovascular events in a population at high risk of premature morbidity and mortality. PMID:18393052

  16. Alpha adrenergic receptor mediation of cardiovascular and metabolic responses to alcohol

    SciTech Connect

    Brackett, D.J.; Gauvin, D.V.; Lerner, M.R.; Holloway, F.H.; Wilson, M.F. Veterans Affairs Medical Center, Oklahoma City, OK )

    1992-02-26

    The role of alpha adrenergic receptors in acute cardiovascular and metabolic responses to alcohol (ETOH) have not been clearly defined. In this study two groups of male Sprague-Dawley rats were given intravenous phentolamine mesylate or saline prior to intragastric alcohol to blockade of alpha receptors during alcohol intoxication in conscious rats. ETOH alone evoked an increase in systemic vascular resistance (SVR), heart rate (HR), and blood glucose concentrations (G) and a decrease in mean arterial pressure (MAP), cardiac output (CO), central venous pressure (CVP), respiration rate (RR) and cardiac stroke volume (SV). Blood alcohol concentration (BAC) peaked at 30 min and remained elevated for the four hrs of monitoring. Phentolamine pretreatment produced a decrease in MAP and SV and an increase in HR. However, antagonism of the alpha receptor blocked the decrease in CO and the increase in SVR and G. The decrease in CVP was unaffected. Surprisingly, the early rise and peak in BAC in the phentolamine treated group was attenuated, but was the same as the untreated group during the final 3 hrs. These data suggest that alpha receptors are significant mediators of cardiovascular and glucoregulatory responses elicited by alcohol. Furthermore, alpha receptor blockade appears to effect the absorption and/or distribution of intragastrically administered alcohol.

  17. Mathematical modeling of human cardiovascular system for simulation of orthostatic response

    NASA Technical Reports Server (NTRS)

    Melchior, F. M.; Srinivasan, R. S.; Charles, J. B.

    1992-01-01

    This paper deals with the short-term response of the human cardiovascular system to orthostatic stresses in the context of developing a mathematical model of the overall system. It discusses the physiological issues involved and how these issues have been handled in published cardiovascular models for simulation of orthostatic response. Most of the models are stimulus specific with no demonstrated capability for simulating the responses to orthostatic stimuli of different types. A comprehensive model incorporating all known phenomena related to cardiovascular regulation would greatly help to interpret the various orthostatic responses of the system in a consistent manner and to understand the interactions among its elements. This paper provides a framework for future efforts in mathematical modeling of the entire cardiovascular system.

  18. Mathematical modeling of human cardiovascular system for simulation of orthostatic response.

    PubMed

    Melchior, F M; Srinivasan, R S; Charles, J B

    1992-06-01

    This paper deals with the short-term response of the human cardiovascular system to orthostatic stresses in the context of developing a mathematical model of the overall system. It discusses the physiological issues involved and how these issues have been handled in published cardiovascular models for simulation of orthostatic response. Most of the models are stimulus specific with no demonstrated capability for simulating the responses to orthostatic stimuli of different types. A comprehensive model incorporating all known phenomena related to cardiovascular regulation would greatly help to interpret the various orthostatic responses of the system in a consistent manner and to understand the interactions among its elements. This paper provides a framework for future efforts in mathematical modeling of the entire cardiovascular system. PMID:1621848

  19. Long-term moderate exercise accelerates the recovery of stress-evoked cardiovascular responses.

    PubMed

    Hsu, Yuan-Chang; Tsai, Sheng-Feng; Yu, Lung; Chuang, Jih-Ing; Wu, Fong-Sen; Jen, Chauying J; Kuo, Yu-Min

    2016-01-01

    Psychological stress is an important global health problem. It is well documented that stress increases the incidences of various cardiovascular disorders. Regular exercise is known to reduce resting blood pressure (BP) and heart rate (HR). This study was designed to clarify the effects of long-term exercise on stress-evoked cardiovascular responses and to emphasize post-stress recovery effects. Male Wistar rats underwent 8 weeks of moderate treadmill training, with cardiovascular responses, autonomic nervous system activities and local Fos reactivity changes in the cardiovascular regulation center were monitored before, during and after immobilization stress. A spectral analysis of cardiovascular parameters was used to examine autonomic nervous activities. We found that long-term exercise (i) lowered resting BP, HR and sympathetic activity, but increased resting parasympathetic activity and baroreflex sensitivity (BRS); (ii) accelerated post-stress recovery of stress-evoked cardiovascular and sympathetic responses along with increased BRS and (iii) accelerated post-stress recovery of stress-evoked neuron activations in the paraventricular nucleus, but delayed it in the nucleus of the tractus solitarius. We conclude that, in rats, long-term exercise accelerated recovery of stress-evoked cardiovascular responses differentially altering hypothalamic and medullar neuron activities.

  20. The effects of behavior therapy, self-relaxation, and transcendental meditation on cardiovascular stress response.

    PubMed

    Puente, A E; Beiman, I

    1980-01-01

    Compared Behavior Therapy (BT), self-relaxation (SR), transcendental meditation (TM), and a waiting-list control group (WL) on measures of cardiovascular and subjective stress response. Male and female respondents (N = 60) to an ad for therapy were evaluated in assessment sessions before and after treatment. The results indicate that BT and SR were more effective than either TM or WL in reducing cardiovascular stress response. These data were interpreted as resulting from therapeutic suggestion and positively reinforced client progress.

  1. Cardiovascular responses to lead are biphasic, while methylmercury, but not inorganic mercury, monotonically increases blood pressure in rats.

    PubMed

    Wildemann, Tanja M; Mirhosseini, Naghmeh; Siciliano, Steven D; Weber, Lynn P

    2015-02-01

    Cardiovascular diseases, such as heart attack and stroke, are the major cause of death worldwide. It is well known that a high number of environmental and physiological risk factors contribute to the development of cardiovascular diseases. Although risk factors are additive, increased blood pressure (hypertension) is the greatest risk factor. Over the last two decades, a growing number of epidemiological studies associate environmental exposure to lead or mercury species with hypertension. However, cardiovascular effects beyond blood pressure are rarely studied and thresholds for effect are not yet clear. To explore effects of lead or mercury species on the cardiovascular system, normal male Wistar rats were exposed to a range of doses of lead, inorganic mercury or methylmercury through the drinking water for four weeks. High-resolution ultrasound was used to measure heart and vascular function (carotid artery blood flow) at baseline and at the end of the exposure, while blood pressure was measured directly in the femoral artery at the end of the 4-week exposure. After 4 weeks, blood pressure responses to lead were biphasic. Low lead levels decreased blood pressure, dilated the carotid artery and increased cardiac output. At higher lead doses, rats had increased blood pressure. In contrast, methylmercury-exposed rats had increased blood pressure at all doses despite dilated carotid arteries. Inorganic mercury did not show any significant cardiovascular effects. Based on the current study, the benchmark dose level 10% (BMDL10s) for systolic blood pressure for lead, inorganic mercury and methylmercury are 1.1, 1.3 and 1.0 μg/kg-bw/d, respectively. However, similar total mercury blood levels attributed to inorganic mercury or methylmercury produced strikingly different results with inorganic mercury having no observable effect on the cardiovascular system but methylmercury increasing systolic and pulse pressures. Therefore, adverse cardiovascular effects cannot be

  2. Type A Behavior and Cardiovascular Responsivity in Preschoolers.

    ERIC Educational Resources Information Center

    Brown, Marie Scott; Tanner, Christine

    This study investigated Type A behavior in preschool children and its relation to cardiovascular reactivity. One hundred forty-four children from 3.5 to 6.5 years old were categorized by their teachers according to the Matthews Youth Test for Health (MYTH) as Type A, Mixed, or Type B. The children's pulse, pulse rate variability, and blood…

  3. Let's Produce Culturally Responsive Pedagogues on Deck

    ERIC Educational Resources Information Center

    Jett, Christopher C.

    2012-01-01

    In this response, I extend the conversation started by Hayes and Juarez (2012) by highlighting how culturally responsive teaching is spoken in one teacher education program where I worked and served in the preparation of middle-level teachers. I also share my reflections concerning this idea and pose questions for critical thought, dialogue, and…

  4. Effect of fluid countermeasures of varying osmolarity on cardiovascular responses to orthostatic stress

    NASA Technical Reports Server (NTRS)

    Davis, John E.

    1989-01-01

    Current operational procedures for shuttle crewmembers include the ingestion of a fluid countermeasure approximately 2 hours before reentry into the earth's gravitational field. The ingestion of the fluid countermeasure is thought to restore plasma volume and improve orthostatic responses upon reentry. The present countermeasure consists of ingesting salt tablets and water to achieve an isotonic solution. It has yet to be determined whether this is the optimal drink to restore orthostatic tolerance. It is also not known whether the drink solution is effective in increasing plasma volume. The purpose here is to evaluate the effectiveness of drink solutions of different osmolarity on restoring plasma volume and orthostatic responses. A hypertonic drink solution was more effective in restoring plasma volume after dehydration than an isotonic solution. However, there were no differences in their effects on an orthostatic challenge. These data suggest that the plasma volume differences produced in this study were not sufficient to produce differences in the cardiovascular responses to an orthostatic challenge, or there are other changes that occur during space flight that are more important in determining orthostatic intolerance.

  5. Predictions of cardiovascular responses during STS reentry using mathematical models

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.; Srinivasan, R.

    1985-01-01

    The physiological adaptation to weightless exposure includes cardiovascular deconditioning arising in part from a loss of total circulating blood volume and resulting in a reduction of orthostatic tolerance. The crew of the Shuttle orbiter are less tolerant to acceleration forces in the head-to-foot direction during the reentry phase of the flight at a time they must function at a high level of performance. The factors that contribute to orthostatic intolerance during and following reentry and to predict the likelihood of impaired crew performance are evaluated. A computer simulation approach employing a mathematical model of the cardiovascular system is employed. It is shown that depending on the severity of blood volume loss, the reentry acceleration stress may be detrimental to physiologic function and may place the physiologic status of the crew near the borderline of some type of impairment. They are in agreement with conclusions from early ground-based experiments and from observations of early Shuttle flights.

  6. Cardiovascular response to histamine during normoxaemia and hypoxaemia in piglets.

    PubMed

    Taylor, B J

    1989-02-01

    The cardiovascular effects of exogenously administered histamine were investigated in conscious newborn piglets aged 10-11 days during normoxia (21% (v/v) O2) and during isocapneic alveolar hypoxia (10% O2, 3% CO2, 87% N2) to determine its influence on preexisting vascular tone. In the first set of experiments (n = 6), four histamine doses (1,10,50,100 micrograms/kg) were tested in sequence during normoxia. Histamine was injected intravenously and cardiovascular variables were recorded. Heart rate increased at all doses studied. Pulmonary and systemic arterial pressures, cardiac output and stroke volume were unchanged at the low histamine doses (1 and 10 micrograms), but all decreased at the high doses (50 and 100 micrograms). Pulmonary and systemic vascular resistances were unchanged at each dose. In the second set of experiments (n = 7), two histamine doses (1 and 5 micrograms/kg) were administered during alveolar hypoxia. Hypoxia caused increases in heart rate and pulmonary arterial pressure and resistance. After injection of each dose of histamine, pulmonary pressure and resistance decreased but remained higher than baseline. No other measured cardiovascular variables were altered. Thus, during normoxia histamine did not alter vascular tone, but high doses did adversely affect myocardial function. During alveolar hypoxia histamine caused weak pulmonary vasodilation at doses that did not alter systemic vascular tone. Histamine is not a potent modifier of the circulation in the newborn piglet during conditions of normoxaemia or hypoxaemia.

  7. Functional analysis of hypothalamic control of the cardiovascular responses accompanying emotional behavior.

    PubMed

    Smith, O A; Astley, C A; DeVito, J L; Stein, J M; Walsh, K E

    1980-06-01

    The cardiovascular (CV) responses to an acute emotional situation in unanesthetized, chair-restrained baboons include elevations in heart rate, blood pressure, and terminal aortic flow and a complex biphasic reduction in renal flow. The same CV responses can be produced by stimulating an area in the hypothalamus. Furthermore, bilateral ablation of the hypothalamic area eliminates CV responses to the emotional behavior while responses to exercise, free feed, and lever press remain unaltered. This effect is not due to memory loss, loss of emotionality, or a general loss of CV regulatory capacity. Efferent projections of the hypothalamic site were traced by means of autoradiography and afferent sources were traced by horseradish peroxidase injections. Efferents include projections to amygdala, central gray, zona incerta, midline thalamic nuclei, dorsal midbrain tegmentum, the parabrachial region. Afferents were widely distributed and included inputs from the subiculum, amygdala, septal area, central gray, locus ceruleus, interpeduncular nucleus, and bilateral labeling in and around the dorsal motor nucleus of X and the nucleus ambiguus.

  8. Mechanical signaling and the cellular response to extracellular matrix in angiogenesis and cardiovascular physiology

    NASA Technical Reports Server (NTRS)

    Ingber, Donald E.

    2002-01-01

    Great advances have been made in the identification of the soluble angiogenic factors, insoluble extracellular matrix (ECM) molecules, and receptor signaling pathways that mediate control of angiogenesis--the growth of blood capillaries. This review focuses on work that explores how endothelial cells integrate these chemical signals with mechanical cues from their local tissue microenvironment so as to produce functional capillary networks that exhibit specialized form as well as function. These studies have revealed that ECM governs whether an endothelial cell will switch between growth, differentiation, motility, or apoptosis programs in response to a soluble stimulus based on its ability to mechanically resist cell tractional forces and thereby produce cell and cytoskeletal distortion. Transmembrane integrin receptors play a key role in this mechanochemical transduction process because they both organize a cytoskeletal signaling complex within the focal adhesion and preferentially focus mechanical forces on this site. Molecular filaments within the internal cytoskeleton--microfilaments, microtubules, and intermediate filaments--also contribute to the cell's structural and functional response to mechanical stress through their role as discrete support elements within a tensegrity-stabilized cytoskeletal array. Importantly, a similar form of mechanical control also has been shown to be involved in the regulation of contractility in vascular smooth muscle cells and cardiac myocytes. Thus, the mechanism by which cells perform mechanochemical transduction and the implications of these findings for morphogenetic control are discussed in the wider context of vascular development and cardiovascular physiology.

  9. Cardiovascular Response Identification Based on Nonlinear Support Vector Regression

    NASA Astrophysics Data System (ADS)

    Wang, Lu; Su, Steven W.; Chan, Gregory S. H.; Celler, Branko G.; Cheng, Teddy M.; Savkin, Andrey V.

    This study experimentally investigates the relationships between central cardiovascular variables and oxygen uptake based on nonlinear analysis and modeling. Ten healthy subjects were studied using cycle-ergometry exercise tests with constant workloads ranging from 25 Watt to 125 Watt. Breath by breath gas exchange, heart rate, cardiac output, stroke volume and blood pressure were measured at each stage. The modeling results proved that the nonlinear modeling method (Support Vector Regression) outperforms traditional regression method (reducing Estimation Error between 59% and 80%, reducing Testing Error between 53% and 72%) and is the ideal approach in the modeling of physiological data, especially with small training data set.

  10. Review of extended producer responsibility: A case study approach.

    PubMed

    Gupt, Yamini; Sahay, Samraj

    2015-07-01

    Principles of extended producer responsibility have been the core of most of the recent policies and legislation dealing with the end-of-life management of recyclable goods. This article makes an exploratory review of 27 cases of extended producer responsibility from developed and developing economies with and without informal recycling, to ascertain the most important aspect of extended producer responsibility. A comparative analysis of the cases with respect to role of stakeholders in the upstream and downstream stages of the extended producer responsibility has been carried out. Further, the study uses exploratory factor analysis to determine the important aspects of the extended producer responsibility in practice using 13 variables identified from the review. Findings of the comparative analysis reveal that financial responsibility of the producers and separate collecting and recycling agencies contributed significantly to the success of the extended producer responsibility-based environmental policies. Regulatory provisions, take-back responsibility and financial flow come out to be the three most important aspects of the extended producer responsibility. Presence of informal sector had a negative impact on the regulatory provisions. The outcomes of this study could serve as a guideline for designing of effective extended producer responsibility-based policies. PMID:26185163

  11. Cardiovascular Responses to Psychosocial Stress Reflect Motivation State in Adults Born at Extremely Low Birth Weight.

    PubMed

    Mathewson, Karen J; Pyhälä, Riikka; Hovi, Petteri; Räikkönen, Katri; Van Lieshout, Ryan J; Boyle, Michael H; Saigal, Saroj; Morrison, Katherine M; Kajantie, Eero; Schmidt, Louis A

    2015-01-01

    Background. Adults born extremely preterm appear to have more difficulty managing the stresses of early adulthood than their term-born peers. Objective. To examine the effects of being born at extremely low birth weight (ELBW; birth weight < 1000 g) versus at full term on cardiovascular responses to stress. Method. Cardiovascular responses were elicited during administration of a widely used laboratory stressor, the Trier Social Stress Test (TSST). Results. Term-born adults exhibited a larger decrease in total peripheral resistance and larger increase in cardiac output for TSST performance, reflecting greater resilience, than did ELBW adults. Furthermore, in ELBW participants but not controls, cardiovascular responses were correlated with anxiety, suggesting that their responses reflected feelings of stress. Conclusions. Skills-training and practice with relevant stressors may be necessary to increase the personal resources of ELBW participants for managing stress as they transition to adulthood. PMID:27335948

  12. Cardiovascular regulatory response to lower body negative pressure following blood volume loss

    NASA Technical Reports Server (NTRS)

    Shimizu, M.; Ghista, D. N.; Sandler, H.

    1979-01-01

    An attempt is made to explain the cardiovascular regulatory responses to lower body negative pressure (LBNP) stress, both in the absence of and following blood or plasma volume loss, the latter being factors regularly observed with short- or long-term recumbency or weightlessness and associated with resulting cardiovascular deconditioning. Analytical expressions are derived for the responses of mean venous pressure and blood volume pooled in the lower body due to LBNP. An analysis is presented for determining the HR change due to LBNP stress following blood volume loss. It is concluded that the reduced orthostatic tolerance following long-term space flight or recumbency can be mainly attributed to blood volume loss, and that the associated cardiovascular responses characterizing this orthostatic intolerance is elicited by the associated central venous pressure response.

  13. Contribution of infralimbic cortex in the cardiovascular response to acute stress.

    PubMed

    Müller-Ribeiro, Flávia Camargos de Figueirêdo; Zaretsky, Dmitry V; Zaretskaia, Maria V; Santos, Robson A S; DiMicco, Joseph A; Fontes, Marco Antônio Peliky

    2012-09-15

    The infralimbic region of the medial prefrontal cortex (IL) modulates autonomic and neuroendocrine function via projections to subcortical structures involved in the response to stress. We evaluated the contribution of the IL to the cardiovascular response evoked by acute stress. Under anesthesia (80 mg/kg ketamine-11.5 mg/kg xylazine), rats were implanted with telemetry probes or arterial lines for recording heart rate and blood pressure. Guide cannulas were implanted to target the IL for microinjection of muscimol (100 pmol/100 nl), N-methyl-d-aspartate (NMDA) (6 pmol/100 nl), or vehicle (100 nl). Microinjection of muscimol, an agonist of GABA(A) receptors, into the IL had no effect on stress-evoked cardiovascular and thermogenic changes in any of the paradigms evaluated (cage switch, restraint plus air-jet noise, or air-jet stress). However, microinjection of the excitatory amino acid NMDA into the IL attenuated the pressor and tachycardic response to air-jet stress. Pretreatment with the selective NMDA antagonist dl-2-amino-5-phosphonopentanoic acid (AP-5, 100 pmol/100 nl) blocked the effect of NMDA on the cardiovascular response to air-jet stress. We conclude that 1) the IL region is not tonically involved in cardiovascular or thermogenic control during stress or under baseline conditions, and 2) activation of NMDA receptors in the IL can suppress the cardiovascular response to acute stress exposure.

  14. Cardiovascular response of rats exposed to 60-Hz electric fields

    SciTech Connect

    Hilton, D.I.; Phillips, R.D.

    1980-01-01

    Recently, it has been reported that exposure to high-strength electric fields can influence electrocardiogram (ECG) patterns, heart rates, and blood pressures in various species of animals. Our studies were designed to evaluate these reported effects and to help clarify some of the disagreement present in the literature. Various cardiovascular variables were measured in Sprague-Dawley rats exposed or sham-exposed to 60-Hz electric fields at 80 to 100 kV/m for periods up to four months. No significant differences in heart rates, ECG patterns, blood pressures, or vascular reactivity were observed between exposed and sham-exposed rats after 8 hours, 40 hours, 1 month, or 4 months of exposure. Our studies cannot be directly compared to the work of other investigators because of differences in animal species and electric-field characteristics. However, our failure to detect any cardiovascular changes may have been the result of (1) eliminating secondary field effects such as shocks, audible noise, corona, and ozone; (2) minimizing steady-state microcurrents between the mouth of the animal and watering devices; and (3) minimizing electric-field-induced vibration of the electrodes and animal cages.

  15. Increasing blood flow to exercising muscle attenuates systemic cardiovascular responses during dynamic exercise in humans.

    PubMed

    Ichinose, Masashi; Ichinose-Kuwahara, Tomoko; Kondo, Narihiko; Nishiyasu, Takeshi

    2015-11-15

    Reducing blood flow to working muscles during dynamic exercise causes metabolites to accumulate within the active muscles and evokes systemic pressor responses. Whether a similar cardiovascular response is elicited with normal blood flow to exercising muscles during dynamic exercise remains unknown, however. To address that issue, we tested whether cardiovascular responses are affected by increases in blood flow to active muscles. Thirteen healthy subjects performed dynamic plantarflexion exercise for 12 min at 20%, 40%, and 60% of peak workload (EX20, EX40, and EX60) with their lower thigh enclosed in a negative pressure box. Under control conditions, the box pressure was the same as the ambient air pressure. Under negative pressure conditions, beginning 3 min after the start of the exercise, the box pressure was decreased by 20, 45, and then 70 mmHg in stepwise fashion with 3-min step durations. During EX20, the negative pressure had no effect on blood flow or the cardiovascular responses measured. However, application of negative pressure increased blood flow to the exercising leg during EX40 and EX60. This increase in blood flow had no significant effect on systemic cardiovascular responses during EX40, but it markedly attenuated the pressor responses otherwise seen during EX60. These results demonstrate that during mild exercise, normal blood flow to exercising muscle is not a factor eliciting cardiovascular responses, whereas it elicits an important pressor effect during moderate exercise. This suggests blood flow to exercising muscle is a major determinant of cardiovascular responses during dynamic exercise at higher than moderate intensity.

  16. Increasing blood flow to exercising muscle attenuates systemic cardiovascular responses during dynamic exercise in humans.

    PubMed

    Ichinose, Masashi; Ichinose-Kuwahara, Tomoko; Kondo, Narihiko; Nishiyasu, Takeshi

    2015-11-15

    Reducing blood flow to working muscles during dynamic exercise causes metabolites to accumulate within the active muscles and evokes systemic pressor responses. Whether a similar cardiovascular response is elicited with normal blood flow to exercising muscles during dynamic exercise remains unknown, however. To address that issue, we tested whether cardiovascular responses are affected by increases in blood flow to active muscles. Thirteen healthy subjects performed dynamic plantarflexion exercise for 12 min at 20%, 40%, and 60% of peak workload (EX20, EX40, and EX60) with their lower thigh enclosed in a negative pressure box. Under control conditions, the box pressure was the same as the ambient air pressure. Under negative pressure conditions, beginning 3 min after the start of the exercise, the box pressure was decreased by 20, 45, and then 70 mmHg in stepwise fashion with 3-min step durations. During EX20, the negative pressure had no effect on blood flow or the cardiovascular responses measured. However, application of negative pressure increased blood flow to the exercising leg during EX40 and EX60. This increase in blood flow had no significant effect on systemic cardiovascular responses during EX40, but it markedly attenuated the pressor responses otherwise seen during EX60. These results demonstrate that during mild exercise, normal blood flow to exercising muscle is not a factor eliciting cardiovascular responses, whereas it elicits an important pressor effect during moderate exercise. This suggests blood flow to exercising muscle is a major determinant of cardiovascular responses during dynamic exercise at higher than moderate intensity. PMID:26377556

  17. Action of adenosine receptor antagonists on the cardiovascular response to defence area stimulation in the rat.

    PubMed Central

    St Lambert, J H; Dawid-Milner, M S; Silva-Carvalho, L; Spyer, K M

    1994-01-01

    1. The action of adenosine in the mediation of the cardiovascular changes associated with the defence reaction has been investigated in the rat using two A1 receptor antagonists. 2. Cumulative doses of 1,3 dipropyl-cyclopentylxanthine (DPCPX) (0.3-3 mg kg-1) and ethanol (0.03-0.25 ml) and bolus doses of DPCPX (3 mg kg-1) and 8-sulphophenyltheophylline (8-SPT) (20 mg kg-1) were given into alpha-chloralose, paralysed and artificially ventilated rats. Recordings were made of arterial blood pressure and heart rate. 3. Ethanol, the vehicle for DPCPX, failed to modify the magnitude of the defence response; however, cumulative doses of DPCPX produced a dose-dependent decrease in the HDA (hypothalamic defence area)-evoked increase in arterial blood pressure, accompanied by a similar fall in the magnitude of the evoked heart rate response. 4. The evoked rise in arterial blood pressure was reduced significantly by intravenous injection of DPCPX (3 mg kg-1) but not 8-SPT (20 mg kg-1), a purely peripherally acting adenosine antagonist. 5. These results suggest that adenosine acting at A1 receptors located in the central nervous system, is involved in the HDA-evoked pressor response. Whilst the site of action of the A1 receptors is not known, possible locations are discussed. PMID:7812606

  18. Cardiovascular Responses during Head-Down Crooked Kneeling Position Assumed in Muslim Prayers

    PubMed Central

    Ahmad Rufa’i, Adamu; Hamu Aliyu, Hadeezah; Yunoos Oyeyemi, Adetoyeje; Lukman Oyeyemi, Adewale

    2013-01-01

    Background: Movement dysfunction may be expressed in terms of symptoms experienced in non-physiological postures, and head-down crooked kneeling (HDCK) is a posture frequently assumed by Muslims during prayer activities. The purpose of this study was to investigate the cardiovascular responses in the HDCK posture. Methods: Seventy healthy volunteers, comprising 35 males and 35 females, participated in the study. Cardiovascular parameters of blood pressure and pulse rate of the participants were measured in rested sitting position and then at one and three minutes into the HDCK posture. Two-way ANOVA was used to determine the differences between cardiovascular responses at rest and in the HDCK posture, and the Student t test was utilized to determine gender difference in cardiovascular responses at rest and at one and three minutes into the HDCK posture. Results: The study showed a significant decrease in systolic and diastolic blood pressures at one minute into the HDCK posture and an increase in pulse rate at one and three minutes into the HDCK posture, as compared to the resting values. Rate pressure product also rose at one minute into the HDCK posture, whereas pulse pressure increased at one and three minutes into the HDCK posture, as compared with the resting values. However, no significant change was observed in the mean arterial pressure values. Conclusion: The findings from this study suggest that no adverse cardiovascular event can be expected to occur for the normal duration of this posture during Muslim prayer activities. PMID:24031108

  19. Increasing Prescription Length Could Cut Cardiovascular Disease Burden And Produce Savings In South Africa

    PubMed Central

    Gaziano, Thomas; Cho, Sylvia; Sy, Stephen; Pandya, Ankur; Levitt, Naomi S.; Steyn, Krisela

    2016-01-01

    South Africa's rates of statin use are among the world's lowest, despite statins’ demonstrated effectiveness for people with a high blood cholesterol level or history of cardiovascular disease. Almost 5 percent of the country's total mortality has been attributed to high cholesterol levels, fueled in part by low levels of statin adherence. Drawing upon experience elsewhere, we used a microsimulation model of cardiovascular disease to investigate the health and economic impacts of increasing prescription length from the standard thirty days to either sixty or ninety days, for South African adults on a stable statin regimen. Increasing prescription length to sixty or ninety days could save 1,694 or 2,553 lives per million adults, respectively. In addition, annual per patient costs related to cardiovascular disease would decrease by $152.41 and $210.29, respectively. Savings would largely accrue to patients in the form of time savings and reduced transportation costs, as a result of less frequent trips to the pharmacy. Increasing statin prescription length would both save resources and improve health outcomes in South Africa. PMID:26355061

  20. Evolution of testosterone treatment over 25 years: symptom responses, endocrine profiles and cardiovascular changes

    PubMed Central

    Carruthers, Malcolm; Cathcart, Paul; Feneley, Mark R.

    2015-01-01

    Abstract Introduction: Testosterone treatment has evolved rapidly over the past 25 years as new, more effective and convenient methods have become available. This study reports experience with seven different methods, introduced on the market in the UK. Aim: To establish the symptom response when testosterone treatment was initiated on the basis of clinical features and symptoms of androgen deficiency, and the resulting endocrine, biochemical and physiological responses. Methods: Of 2693 patients attending the 3 Men’s Health Centers – The UK Androgen Study (UKAS), 2247 were treated. Treatments included pellet implants, oral testosterone undecanoate (Testocaps), mesterolone (Proviron), testosterone gel (Testogel), testosterone scrotal cream (Andromen) and scrotal gel (Tostran). Results: There was no correlation between initial testosterone level, initial symptom score or the success of treatment as defined by adequate resolution of symptoms. Despite the diverse endocrine patterns produced, the testosterone preparations appear equally safe over prolonged periods, with either no change or improvement of cardiovascular risk factors, especially in lowering cholesterol and diastolic blood pressure. Conclusions: It is suggested that because of excessive reliance on laboratory measures of androgens and undue safety concerns, many men who could benefit from symptom relief, improvement in related clinical conditions and given preventive medical benefits remain untreated. PMID:26218766

  1. Cardiovascular responses induced by obstructive apnea are enhanced in hypertensive rats due to enhanced chemoreceptor responsivity.

    PubMed

    Angheben, Juliana M M; Schoorlemmer, Guus H M; Rossi, Marcio V; Silva, Thiago A; Cravo, Sergio L

    2014-01-01

    Spontaneously hypertensive rats (SHR), like patients with sleep apnea, have hypertension, increased sympathetic activity, and increased chemoreceptor drive. We investigated the role of carotid chemoreceptors in cardiovascular responses induced by obstructive apnea in awake SHR. A tracheal balloon and vascular cannulas were implanted, and a week later, apneas of 15 s each were induced. The effects of apnea were more pronounced in SHR than in control rats (Wistar Kyoto; WKY). Blood pressure increased by 57±3 mmHg during apnea in SHR and by 28±3 mmHg in WKY (p<0.05, n = 14/13). The respiratory effort increased by 53±6 mmHg in SHR and by 34±5 mmHg in WKY. The heart rate fell by 209±19 bpm in SHR and by 155±16 bpm in WKY. The carotid chemoreceptors were then inactivated by the ligation of the carotid body artery, and apneas were induced two days later. The inactivation of chemoreceptors reduced the responses to apnea and abolished the difference between SHR and controls. The apnea-induced hypertension was 11±4 mmHg in SHR and 8±4 mmHg in WKY. The respiratory effort was 15±2 mmHg in SHR and 15±2 mmHg in WKY. The heart rate fell 63±18 bpm in SHR and 52±14 bpm in WKY. Similarly, when the chemoreceptors were unloaded by the administration of 100% oxygen, the responses to apnea were reduced. In conclusion, arterial chemoreceptors contribute to the responses induced by apnea in both strains, but they are more important in SHR and account for the exaggerated responses of this strain to apnea.

  2. Angiotensin-(1-7) in the basolateral amygdala attenuates the cardiovascular response evoked by acute emotional stress.

    PubMed

    Oscar, Charles Gonzaga; Müller-Ribeiro, Flávia Camargos de Figueirêdo; de Castro, Lidiane Gonzaga; Martins Lima, Augusto; Campagnole-Santos, Maria José; Santos, Robson Augusto Souza; Xavier, Carlos Henrique; Fontes, Marco Antônio Peliky

    2015-01-12

    The basolateral amygdala (BLA) plays a critical role in mediating physiological responses to emotional stress. Recent data suggest that angiotensin-(1-7) [Ang-(1-7)] can act centrally attenuating the cardiovascular response to acute stress. We investigated whether Ang-(1-7) in the BLA plays a role in the cardiovascular response to emotional stress. Under anesthesia, guide cannulas were implanted into the BLA of Wistar rats. Five days later, the femoral artery was cannulated for mean arterial pressure (MAP) and heart rate (HR) recordings. Microinjections of Ang-(1-7) (5 or 50 pmol), the Mas receptor antagonist A-779 (100 pmol), Ang-(1-7)+A-779 (50 + 100 pmol, respectively), or vehicle (NaCl 0.9%, control) were performed after 24h and rats were then submitted to stress trials. Injection of Ang-(1-7) into the BLA blocked the tachycardia (ΔHR: vehicle 135 ± 23 vs. Ang-(1-7) 9 ± 12 bpm; P<0.05) and the pressor response (ΔMAP: vehicle 28 ± 3 mmHg vs. Ang-(1-7) 6 ± 2 mmHg; P<0.05) produced by air jet stress. These effects were completely reversed by A-779 (ΔHR: 109 ± 11 bpm; ΔMAP: 18 ± 2 mmHg). Ang-(1-7) into the BLA also attenuated the pressor response evoked by cage-switch stress paradigm. These findings indicate that Ang-(1-7) can act in the BLA through the Mas receptors modulating the cardiovascular response evoked by emotional stress.

  3. Cardiovascular and organ responses and adaptation responses to hypogravity in an experimental animal model.

    NASA Astrophysics Data System (ADS)

    Biondi, R.; Capodicasa, E.; Tassi, C.; Mezzasomal, L.; Benedetti, C.; Valiani, M.; Marconi, P.; Rossi, R.

    1995-10-01

    The head-down suspension (i.e antiorthostatic hypokinesia) rat is used to simulate weightlessness. However, little is known about cardiovascular and organ adaptation responses which, over a long time, can become pathologically significant. The purpose of this study was therefore to evaluate regional changes in the hematology parameters, Endotheline-1 (ET-1) concentration and urinary excretion of N-acetyl-β-D-glucosaminidase (EC 3.2.1.30) (NAG) in an experimental antiorthostatic rat model. The data indicate significant variations in the plasma ET-1 level in time, in the superior and inferior cava vessel blood of animals maintained for 10 days in hypogravity with respect to controls. These changes do not seem to be due to hemoconcentration. The increase in urinary NAG was observed during the first 24h of experiment, indicating renal stress, probably due to adverse blood flow variations within the organ. We conclude that the plasma ET-1 level changes could be responsible, overall for the blood flow variations in the kidney and renal stress could be the consequence of extended antiorthostatic hypokinesia. The ET-1 behaviour and urinary NAG excretion in rats exposed to antiorthostatic hypokjnetic hydynamia offer possibilities for understanding if these changes might be reversible or when they become pathological. This could give some relevant information about the effects of prolonged hypogravity during the space voyage.

  4. Greater cardiovascular responses to laboratory mental stress are associated with poor subsequent cardiovascular risk status: a meta-analysis of prospective evidence.

    PubMed

    Chida, Yoichi; Steptoe, Andrew

    2010-04-01

    An increasing number of studies has tested whether greater cardiovascular responses to acute mental stress predict future cardiovascular disease, but results have been variable. This review aimed quantitatively to evaluate the association between cardiovascular responses to laboratory mental stress and subsequent cardiovascular risk status in prospective cohort studies. We searched general bibliographic databases, PsycINFO, Web of Science, and PubMed, up to December 2009. Two reviewers independently extracted data on study characteristics, quality, and estimates of associations. There were 169 associations (36 articles) of stress reactivity and 30 associations (5 articles) of poststress recovery in relation to future cardiovascular risk status, including elevated blood pressure, hypertension, left ventricular mass, subclinical atherosclerosis, and clinical cardiac events. The overall meta-analyses showed that greater reactivity to and poor recovery from stress were associated longitudinally with poor cardiovascular status (r=0.091 [95% CI: 0.050 to 0.132], P<0.001, and r=0.096 [95% CI: 0.058 to 0.134], P<0.001, respectively). These findings were supported by more conservative analyses of aggregate effects and by subgroup analyses of the methodologically strong associations. Notably, incident hypertension and increased carotid intima-media thickness were more consistently predicted by greater stress reactivity and poor stress recovery, respectively, whereas both factors were associated with higher future systolic and diastolic blood pressures. In conclusion, the current meta-analysis suggests that greater responsivity to acute mental stress has an adverse effect on future cardiovascular risk status, supporting the use of methods of managing stress responsivity in the prevention and treatment of cardiovascular disease.

  5. Concord grape juice polyphenols and cardiovascular risk factors: dose-response relationships

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pure fruit juices provide nutritional value with evidence suggesting some of their benefits on biomarkers of cardiovascular disease risk may be derived from their constituent polyphenols, particularly flavonoids. However, few data from clinical trials are available on the dose-response relationship ...

  6. Appraisal, Coping, Task Performance, and Cardiovascular Responses during the Evaluated Speaking Task.

    ERIC Educational Resources Information Center

    Baggett, H. Lane; And Others

    1996-01-01

    Appraisal, coping, task performance, and cardiovascular responses were examined among men high and low in speech anxiety who prepared and performed a speech under evaluative conditions. Speech-anxious men saw the task as more threatening. They were more stressed, anxious, distracted, and aware of their emotions, focused on the passage of time, and…

  7. Single-unit responses of serotonergic medullary raphe neurons to cardiovascular challenges in freely moving cats.

    PubMed

    Martin-Cora, Francisco J; Fornal, Casimir A; Jacobs, Barry L

    2005-12-01

    Single-unit activity of serotonergic neurons in the nuclei raphe obscurus (NRO) and raphe pallidus (NRP) were recorded in conjunction with heart rate in freely moving cats in response to systemic administration of vasoactive drugs and to graded haemorrhage. Bolus administration of phenylephrine hydrochloride and sodium nitroprusside (20 microg/kg, i.v.) produced a marked, transient reflex bradycardia (-42 b.p.m.) and tachycardia (+60 b.p.m.), respectively. The activity of NRO/NRP serotonergic neurons remained unchanged after phenylephrine and nitroprusside administration. The administration of hydralazine (1 mg/kg, i.v.), a long-acting vasodilator, produced sustained tachycardia (+60 b.p.m.), which was not accompanied by changes in neuronal activity, despite prolonged reflex activation of the sympathetic nervous system. The initial withdrawal of up to 15% of total blood volume increased heart rate (+12 b.p.m.), whereas the removal of 22.5% of total blood decreased heart rate (-44 b.p.m.). The activity of NRO/NRP serotonergic neurons remained unaltered throughout graded haemorrhage trials, despite the changes in sympathetic outflow. Thus, serotonergic NRO and NRP neurons appear to be insensitive to alterations in blood pressure and baroreceptor activity, and this lack of responsiveness does not support a specific role for these cells in cardiovascular regulation. Furthermore, these neurons do not appear to be involved in physiological mechanisms underlying alterations in autonomic outflow invoked by hypertension and hypotension. Taken within the context of our previous work, the present data suggest that medullary serotonergic neurons may modulate autonomic outflow, but only in relation to their primary role in motor control. PMID:16367786

  8. Role of the autonomic nervous system and baroreflex in stress-evoked cardiovascular responses in rats.

    PubMed

    Dos Reis, Daniel Gustavo; Fortaleza, Eduardo Albino Trindade; Tavares, Rodrigo Fiacadori; Corrêa, Fernando Morgan Aguiar

    2014-07-01

    Restraint stress (RS) is an experimental model to study stress-related cardiovascular responses, characterized by sustained pressor and tachycardiac responses. We used pharmacologic and surgical procedures to investigate the role played by sympathetic nervous system (SNS) and parasympathetic nervous system (PSNS) in the mediation of stress-evoked cardiovascular responses. Ganglionic blockade with pentolinium significantly reduced RS-evoked pressor and tachycardiac responses. Intravenous treatment with homatropine methyl bromide did not affect the pressor response but increased tachycardia. Pretreatment with prazosin reduced the pressor and increased the tachycardiac response. Pretreatment with atenolol did not affect the pressor response but reduced tachycardia. The combined treatment with atenolol and prazosin reduced both pressor and tachycardiac responses. Adrenal demedullation reduced the pressor response without affecting tachycardia. Sinoaortic denervation increased pressor and tachycardiac responses. The results indicate that: (1) the RS-evoked cardiovascular response is mediated by the autonomic nervous system without an important involvement of humoral factors; (2) hypertension results primarily from sympathovascular and sympathoadrenal activation, without a significant involvement of the cardiac sympathetic component (CSNS); (3) the abrupt initial peak in the hypertensive response to restraint is sympathovascular-mediated, whereas the less intense but sustained hypertensive response observed throughout the remaining restraint session is mainly mediated by sympathoadrenal activation and epinephrine release; (4) tachycardia results from CSNS activation, and not from PSNS inhibition; (5) RS evokes simultaneous CSNS and PSNS activation, and heart rate changes are a vector of both influences; (6) the baroreflex is functional during restraint, and modulates both the vascular and cardiac responses to restraint.

  9. Effects of a gravity gradient on human cardiovascular responses

    NASA Technical Reports Server (NTRS)

    Hastreiter, D.; Young, L. R.

    1997-01-01

    Eight subjects participated in one control and three rotation trials on a short-arm centrifuge such that the Gz levels at the feet were 0.5, 1.0, and 1.5 G. Trials consisted of 30 minutes of supine rest, 1 hour of rotation (or in the control, 30 additional minutes of rest and 30 minutes of standing), and a final 30-minute rest period. Measurements of heart rate, calf impedance, calf volume, and blood pressure support the findings that the highest G level is similar to standing and that the lower G levels fail to produce significant effects.

  10. Cardiovascular response to lower body negative pressure stimulation before, during, and after space flight

    NASA Technical Reports Server (NTRS)

    Baisch, F.; Beck, L.; Blomqvist, G.; Wolfram, G.; Drescher, J.; Rome, J. L.; Drummer, C.

    2000-01-01

    BACKGROUND: It is well known that space travel cause post-flight orthostatic hypotension and it was assumed that autonomic cardiovascular control deteriorates in space. Lower body negative pressure (LBNP) was used to assess autonomic function of the cardiovascular system. METHODS: LBNP tests were performed on six crew-members before and on the first days post-flight in a series of three space missions. Additionally, two of the subjects performed LBNP tests in-flight. LBNP mimics fluid distribution of upright posture in a gravity independent way. It causes an artificial sequestration of blood, reduces preload, and filtrates plasma into the lower part of the body. Fluid distribution was assessed by bioelectrical impedance and anthropometric measurements. RESULTS: Heart rate, blood pressure, and total peripheral resistance increased significantly during LBNP experiments in-flight. The decrease in stroke volume, the increased pooling of blood, and the increased filtration of plasma into the lower limbs during LBNP indicated that a plasma volume reduction and a deficit of the interstitial volume of lower limbs rather than a change in cardiovascular control was responsible for the in-flight response. Post-flight LBNP showed no signs of cardiovascular deterioration. The still more pronounced haemodynamic changes during LBNP reflected the expected behaviour of cardiovascular control faced with less intravascular volume. In-flight, the status of an intra-and extravascular fluid deficit increases sympathetic activity, the release of vasoactive substances and consequently blood pressure. Post-flight, blood pressure decreases significantly below pre-flight values after restoration of volume deficits. CONCLUSION: We conclude that the cardiovascular changes in-flight are a consequence of a fluid deficit rather than a consequence of changes in autonomic signal processing.

  11. Cardiovascular activity in blood-injection-injury phobia during exposure: evidence for diphasic response patterns?

    PubMed

    Ritz, Thomas; Meuret, Alicia E; Simon, Erica

    2013-08-01

    Exposure to feared stimuli in blood-injection-injury (BII)-phobia is thought to elicit a diphasic response pattern, with an initial fight-flight-like cardiovascular activation followed by a marked deactivation and possible fainting (vasovagal syncope). However, studies have remained equivocal on the importance of such patterns. We therefore sought to determine the prevalence and clinical relevance of diphasic responses using criteria that require a true diphasic response to exceed cardiovascular activation of an emotional episode of a negative valence and to exceed deactivation of an emotionally neutral episode. Sixty BII-phobia participants and 20 healthy controls were exposed to surgery, anger and neutral films while measuring heart rate, blood pressure, respiratory pattern, and end-tidal partial pressure of carbon dioxide (as indicator of hyperventilation). Diphasic response patterns were observed in up to 20% of BII-phobia participants and 26.6% of healthy controls for individual cardiovascular parameters. BII-phobia participants with diphasic patterns across multiple parameters showed more fear of injections and blood draws, reported the strongest physical symptoms during the surgery film, and showed the strongest tendency to hyperventilate. Thus, although only a minority of individuals with BII phobia shows diphasic responses, their occurrence indicates significant distress. Respiratory training may add to the treatment of BII phobia patients that show diphasic response patterns.

  12. Cardiovascular response to apneic immersion in cool and warm water

    NASA Technical Reports Server (NTRS)

    Folinsbee, L.

    1974-01-01

    The influence of prior exposure to cool water and the influence of lung volume on the responses to breath holding were examined. The bradycardia and vasoconstriction that occur during breath-hold diving in man are apparently the resultant of stimuli from apnea, relative expansion of the thorax, lung volume, esophageal pressure, face immersion, and thermal receptor stimulation. It is concluded that the bradycardia and vasoconstriction associated with breath holding during body immersion are not attenuated by a preexisting bradycardia and vasoconstriction due to cold.

  13. Effects of lower body positive pressure on cardiovascular responses during walking in elderly women.

    PubMed

    Sota, T; Matsuo, S; Uchida, Y; Hagino, H; Kawai, Y

    2013-01-01

    This study was undertaken to investigate the effects of lower body positive pressure (LBPP) on cardiovascular responses during a 15-min walking trial in young (22.1+/-0.4 years) and elderly women (67.8+/-1.1 years). The application of 20 mm Hg LBPP reduced ground reaction forces by 31.2+/-0.5 kgw in both groups. We hypothesized that cardiovascular responses to LBPP during walking were different between the young and elderly subjects. Applying 20 mm Hg of LBPP increased diastolic and mean blood pressure but not systolic blood pressure in both groups. LBPP-induced reduction in heart rate (HR) occurred more quickly in the young group compared to the elderly group (p<0.05). Applying LBPP also decreased double product (systolic blood pressure x HR) in both groups, suggesting that LBPP reduces myocardial oxygen consumption during exercise. These results suggest that heart rate responses to LBPP during exercise vary with increasing age.

  14. Age alters the cardiovascular response to direct passive heating

    NASA Technical Reports Server (NTRS)

    Minson, C. T.; Wladkowski, S. L.; Cardell, A. F.; Pawelczyk, J. A.; Kenney, W. L.

    1998-01-01

    During direct passive heating in young men, a dramatic increase in skin blood flow is achieved by a rise in cardiac output (Qc) and redistribution of flow from the splanchnic and renal vascular beds. To examine the effect of age on these responses, seven young (Y; 23 +/- 1 yr) and seven older (O; 70 +/- 3 yr) men were passively heated with water-perfused suits to their individual limit of thermal tolerance. Measurements included heart rate (HR), Qc (by acetylene rebreathing), central venous pressure (via peripherally inserted central catheter), blood pressures (by brachial auscultation), skin blood flow (from increases in forearm blood flow by venous occlusion plethysmography), splanchnic blood flow (by indocyanine green clearance), renal blood flow (by p-aminohippurate clearance), and esophageal and mean skin temperatures. Qc was significantly lower in the older than in the young men (11.1 +/- 0.7 and 7.4 +/- 0.2 l/min in Y and O, respectively, at the limit of thermal tolerance; P < 0. 05), despite similar increases in esophageal and mean skin temperatures and time to reach the limit of thermal tolerance. A lower stroke volume (99 +/- 7 and 68 +/- 4 ml/beat in Y and O, respectively, P < 0.05), most likely due to an attenuated increase in inotropic function during heating, was the primary factor for the lower Qc observed in the older men. Increases in HR were similar in the young and older men; however, when expressed as a percentage of maximal HR, the older men relied on a greater proportion of their chronotropic reserve to obtain the same HR response (62 +/- 3 and 75 +/- 4% maximal HR in Y and O, respectively, P < 0.05). Furthermore, the older men redistributed less blood flow from the combined splanchnic and renal circulations at the limit of thermal tolerance (960 +/- 80 and 720 +/- 100 ml/min in Y and O, respectively, P < 0. 05). As a result of these combined attenuated responses, the older men had a significantly lower increase in total blood flow directed to

  15. Cardiovascular responses to hypoxia and anaemia in the toad Bufo marinus.

    PubMed

    Andersen, Johnnie B; Hedrick, Michael S; Wang, Tobias

    2003-03-01

    Amphibians exhibit cardiorespiratory responses to hypoxia and, although several oxygen-sensitive chemoreceptor sites have been identified, the specific oxygen stimulus that triggers these responses remains controversial. This study investigates whether the cardiovascular response to oxygen shortage correlates with decreased oxygen partial pressure of arterial blood (Pa(O(2))) or reduced oxygen concentration ([O(2)]) in toads. Toads, equipped with blood flow probes and an arterial catheter, were exposed to graded hypoxia [fraction of oxygen in the inspired air (FI(O(2)))=0.21, 0.15, 0.10, 0.07 and 0.05] before and after reductions in arterial [O(2)] by isovolemic anaemia that reduced haematocrit by approximately 50%. Toads responded to hypoxia by increasing heart rate (fH) and pulmocutaneous blood flow (Q(pc)) and reducing the net cardiac right-to-left-shunt. When arterial [O(2)] was reduced by anaemia, the toads exhibited a similar cardiovascular response to that observed in hypoxia. While arterial CO(2) partial pressure (Pa(CO(2))) decreased significantly during hypoxia, indicative of increased alveolar ventilation, anaemia did not alter Pa(CO(2))). This suggests that reductions in [O(2)] mediate cardiovascular adjustments, while ventilatory responses are caused by reduced Pa(O(2)).

  16. Social Support and Networks: Cardiovascular Responses Following Recall on Immigration Stress Among Chinese Americans

    PubMed Central

    Suchday, Sonia; Wylie-Rosett, Judith

    2014-01-01

    Social support has been shown to act as a buffer for cardiovascular responses to stress. However, little is known about how social support and networks are related to cardiovascular responses to immigration stress recall. The current study evaluated the impact of structural and functional support on cardiovascular reaction following immigrant stress recall provocation as well as the moderation effect of interdependent self-construal among first-generation Chinese immigrants. One hundred fifty Chinese immigrants were recruited in the New York Chinatown area. Participants completed questionnaires assessing their levels of social support and networks, and interdependent self-construal. Following adaptation, participants recalled a recent post-immigration stress-provoking situation. Cardiovascular measures were taken during adaptation, stressor task, and recovery period. Hierarchical multiple regression analysis was performed. Social network size and type, as well as perceived emotional support were positively predictive of systolic blood pressure (SBP) reactivity changes. Instrumental support seeking was a positive predictor of SBP and diastolic blood pressure (DBP) reactivity. The moderation effect between instrumental support seeking and interdependent self-construal were significantly predictive of DBP reactivity and recovery, suggesting that perceptions about themselves in relation to others is a crucial factor for determining whether support seeking is beneficial or not. Social support was not a direct buffer on cardiovascular responses to stress among Chinese immigrants. Chinese values of interdependence and collectivism may partly explain the disconfirming results. Still, when interdependent self-construal was taken into account, Chinese immigrants who had less interdependent self-construal, but solicited more instrumental support, had faster adaptation to stress over the long term. PMID:24288021

  17. Cardiovascular responses during free-diving in the sea.

    PubMed

    Marongiu, E; Crisafulli, A; Ghiani, G; Olla, S; Roberto, S; Pinna, M; Pusceddu, M; Palazzolo, G; Sanna, I; Concu, A; Tocco, F

    2015-04-01

    Cardiac output has never been assessed during free-diving diving in the sea. Knowledge of human diving response in this setting is therefore scarce. 3 immersions were performed by 7 divers: at depths of 10 m, 20 m and 30 m. Each test consisted of 3 apnea phases: descent, static and ascent. An impedance cardiograph provided data on stroke volume, heart rate and cardiac output. Mean blood pressure, arterial O2 saturation and blood lactate values were also collected. Starting from a resting value of 4.5±1.6 L∙min(-1), cardiac output at 10 m showed an increase up to 7.1±2.2 L∙min(-1) (p<0.01) during the descent, while conditions during the static and ascent phases remained unchanged. At 20 m cardiac output values were 7.3±2.4 L∙min(-1) and 6.7(±1).2 L∙min(-1) during ascent and descent, respectively (p<0.01), and 4.3±0.9 L∙min(-1) during static phase. At 30 m cardiac output values were 6.5±1.8 L∙min(-1) and 7.5±2 L∙min(-1) during descent and ascent, respectively (p<0.01), and 4.7±2.1 L∙min(-1) during static phase. Arterial O2 saturation decreased with increasing dive depth, reaching 91.1±3.4% (p<0.001 vs. rest) upon emergence from a depth of 30 m. Blood lactate values increased to 4.1±1.2 mmol∙L(-1) at the end of the 30 m dive (p<0.001 vs. rest). Results seem to suggest that simultaneous activation of exercise and diving response could lead to an absence of cardiac output reduction aimed at an oxygen-conserving effect.

  18. Cardiovascular response to exercise and training in the horse.

    PubMed

    Physick-Sheard, P W

    1985-08-01

    The quality of the overall response to exercise in the horse is very similar to that seen in man and laboratory animals; differences are mainly quantitative and persist when relative body weight is taken into account. The apparently greater flow capacity of the equine muscle bed during maximal whole-body exercise implicates the extent of central circulatory adaptations as the limiting factor in performance but implies a role for increase in arteriolar capacitance/muscle capillarity as an appropriate response to intense endurance training. The blood oxygen-carrying capacity of the horse is often quoted as the major component of the animal's superior aerobic work capacity, although the measured maximal a-vO2 for the horse is only 2 to 3 ml greater than that found in elite athletes. In fact, comparison of published performance data for man and the horse reveals that improved a-vO2 accounts for 23 per cent of the difference, and increased Qc accounts for the remaining 77 per cent of the superior oxygen consumption in the horse. The extent to which the horse can increase Qc and muscle blood flow appears to represent its major adaptations for maximal aerobic performance. It is frequently observed that there have been far greater improvements in human athletic performance than in that of the race-horse, and this difference is usually attributed to the application of scientific training methods to the athlete. It has also been suggested that the horse may have reached the limit of its adaptive ability. The horse has a maximal oxygen pulse of at least 0.6 ml per kg per beat compared with 0.35 for man, a 90 per cent whole body oxygen extraction, and an 80 to 90 per cent higher muscle blood flow, with an overall capability of increasing Vo2 max by 35 times. These represent levels that would appear to be difficult to improve upon. However, insufficient research has been performed to firmly state true maxima for the horse, and current research does not reveal to what extent the

  19. Abnormal cardiovascular responses induced by localized high power microwave exposure

    SciTech Connect

    Lu, S.-T; Brown, D.O.; Johnson, C.E.; Mathur, S.P. ); Elson, E.C. )

    1992-05-01

    A hypothesis of microwave-induced circulatory under perfusion was tested in ketamine anesthetized rats whose heart rate, mean arterial pressure, pulse pressure, respiration rate, and body temperatures were monitored continuously. Fifty-eight ventral head and neck exposures in a waveguide consisted of sham-exposure and exposure to continuous wave (CW) and pulsed 1.25 GHz microwaves for 5 min. The 0.5 Hz and 16 Hz pulsemodulated microwaves were delivered at 400 kW peak power. The CW microwaves were 2 and 6.4 W. The average specific absorption rate was 4.75 W/kg per watt transmitted in the brain and 17.15 W/kg per watt transmitted in the neck. Respiration rate and mean arterial pressure were not altered. Changes in heart rate and pulse pressure were observed in rats exposed to higher power but not to the lower average power microwaves. Depression of pulse pressure, an indication of a decrease in stroke volume, and increased or decreased heart rate were noted in presence of whole-body hyperthermia. The cardiac output of those animals exposed to higher average power microwaves was considered to be below normal as hypothesized. Decreased cardiac output and normal mean arterial pressure resulted in an increase in the total peripheral resistance which was contrary to the anticipated thermal response of animals.

  20. Abnormal cardiovascular responses induced by localized high power microwave exposure.

    PubMed

    Lu, S T; Brown, D O; Johnson, C E; Mathur, S P; Elson, E C

    1992-05-01

    A hypothesis of microwave-induced circulatory under perfusion was tested in ketamine anesthetized rats whose heart rate, mean arterial pressure, pulse pressure, respiration rate, and body temperatures were monitored continuously. Fifty-eight ventral head and neck exposures in a waveguide consisted of sham-exposure and exposure to continuous wave (CW) and pulsed 1.25 GHz microwaves for 5 min. The 0.5 Hz (10 microseconds, 2 W average) and 16 Hz (1 microsecond, 6.4 W average) pulse-modulated microwaves were delivered at 400 kW peak power. The CW microwaves were 2 and 6.4 W. The average specific absorption rate was 4.75 W/kg per watt transmitted in the brain and 17.15 W/kg per watt transmitted in the neck. Respiration rate and mean arterial pressure were not altered. Changes in heart rate and pulse pressure were observed in rats exposed to higher power (16 Hz pulses and 6.4 W CW) but not to the lower average power microwaves (0.5 Hz pulses and 2 W CW). Depression of pulse pressure, an indication of a decrease in stroke volume, and increased (tachycardia) or decreased (bradycardia) heart rate were noted in presence of whole-body hyperthermia. The cardiac output of those animals exposed to higher average power microwaves was considered to be below normal as hypothesized. Decreased cardiac output and normal mean arterial pressure resulted in an increase in the total peripheral resistance which was contrary to the anticipated thermal response of animals. PMID:1388133

  1. Cardiovascular responses to microinjection of L-glutamate into the NTS in AV3V-lesioned rats.

    PubMed

    Vieira, Alexandre Antonio; Colombari, Eduardo; De Luca, Laurival A; de Almeida Colombari, Débora Simões; Menani, José V

    2004-10-29

    The excitatory amino acid L-glutamate injected into the nucleus of the solitary tract (NTS) in unanesthetized rats similar to peripheral chemoreceptor activation increases mean arterial pressure (MAP) and reduces heart rate. In this study, we investigated the effects of acute (1 day) and chronic (15 days) electrolytic lesions of the preoptic-periventricular tissue surrounding the anteroventral third ventricle (AV3V region) on the pressor and bradycardic responses induced by injections of L-glutamate into the NTS or peripheral chemoreceptor activation in unanesthetized rats. Male Holtzman rats with sham or electrolytic AV3V lesions and a stainless steel cannula implanted into the NTS were used. Differently from the pressor responses (28+/-3 mm Hg) produced by injections into the NTS of sham-lesioned rats, L-glutamate (5 nmol/100 nl) injected into the NTS reduced MAP (-26+/-8 mm Hg) or produced no effect (2+/-7 mm Hg) in acute and chronic AV3V-lesioned rats, respectively. The bradycardia to l-glutamate into the NTS and the cardiovascular responses to chemoreflex activation with intravenous potassium cyanide or to baroreflex activation with intravenous phenylephrine or sodium nitroprusside were not modified by AV3V lesions. The results show that the integrity of the AV3V region is essential for the pressor responses to L-glutamate into the NTS but not for the pressor responses to chemoreflex activation, suggesting dissociation between the central mechanisms involved in these responses.

  2. Habitual alcohol consumption is associated with lower cardiovascular stress responses--a novel explanation for the known cardiovascular benefits of alcohol?

    PubMed

    Jones, Alexander; McMillan, Merlin R; Jones, Russell W; Kowalik, Grzegorz T; Steeden, Jennifer A; Pruessner, Jens C; Taylor, Andrew M; Deanfield, John E; Muthurangu, Vivek

    2013-07-01

    In contrast to heavy alcohol consumption, which is harmful, light to moderate drinking has been linked to reduced cardiovascular morbidity and mortality. Effects on lipid status or clotting do not fully explain these benefits. Exaggerated cardiovascular responses to mental stress are detrimental to cardiovascular health. We hypothesized that habitual alcohol consumption might reduce these responses, with potential benefits. Advanced magnetic resonance techniques were used to accurately measure cardiovascular responses to an acute mental stressor (Montreal Imaging Stress Task) in 88 healthy adults (∼1:1 male:female). Salivary cortisol and task performance measures were used to assess endocrine and cognitive responses. Habitual alcohol consumption and confounding factors were assessed by questionnaire. Alcohol consumption was inversely related to responses of heart rate (HR) (r = -0.31, p = 0.01), cardiac output (CO) (r = -0.32, p = 0.01), vascular resistance (r = 0.25, p = 0.04) and mean blood pressure (r = -0.31, p = 0.01) provoked by stress, but not to stroke volume (SV), or arterial compliance changes. However, high alcohol consumers had greater cortisol stress responses, compared to moderate consumers (3.5 versus 0.7 nmol/L, p = 0.04). Cognitive measures did not differ. Findings were not explained by variations in age, sex, social class, ethnicity, physical activity, adrenocortical activity, adiposity, smoking, menstrual phase and chronic stress. Habitual alcohol consumption is associated with reduced cardiac responsiveness during mental stress, which has been linked to lower risk of hypertension and vascular disease. Consistent with established evidence, our findings suggest a mechanism by which moderate alcohol consumption might reduce cardiovascular disease, but not high consumption, where effects such as greater cortisol stress responses may negate any benefits.

  3. The role of neuropeptide Y in the ovine fetal cardiovascular response to reduced oxygenation

    PubMed Central

    Sanhueza, Emilia M; Johansen-Bibby, Anja A; Fletcher, Andrew J W; Riquelme, Raquel A; Daniels, Alejandro J; Serón-Ferré, Maria; Gaete, Cristián R; Carrasco, Jorge E; Llanos, Aníbal J; Giussani, Dino A

    2003-01-01

    This study investigated the role of neuropeptide Y (NPY) in mediating cardiovascular responses to reduced oxygenation in the late gestation ovine fetus by: (1) comparing the effects on the cardiovascular system of an exogenous infusion of NPY with those elicited by moderate or severe reductions in fetal oxygenation; and (2) determining the effect of fetal i.v. treatment with a selective NPY-Y1 receptor antagonist on the fetal cardiovascular responses to acute moderate hypoxaemia. Under general anaesthesia, 14 sheep fetuses (0.8–0.9 of gestation) were surgically prepared with vascular and amniotic catheters. In 5 of these fetuses, a Transonic flow probe was also implanted around a femoral artery. Following at least 5 days of recovery, one group of fetuses (n = 9) was subjected to a 30 min treatment period with exogenous NPY (17 μg kg−1 bolus plus 0.85 μg kg−1 min−1 infusion). In this group, fetal blood pressure and heart rate were monitored continuously and the distribution of the fetal combined ventricular output was assessed via injection of radiolabelled microspheres before and during treatment. The second group of fetuses instrumented with the femoral flow probe (n = 5) were subjected to a 3 h experiment consisting of 1 h of normoxia, 1 h of hypoxaemia, and 1 h of recovery during a slow i.v. infusion of vehicle. One or two days later, the acute hypoxaemia protocol was repeated during fetal i.v. treatment with a selective NPY-Y1 receptor antagonist (50 μg kg−1bolus + 1.5 μg kg−1 min−1 infusion). In these fetuses, fetal arterial blood pressure, heart rate and femoral vascular resistance were recorded continuously. The results show that fetal treatment with exogenous NPY mimics the fetal cardiovascular responses to asphyxia, and that treatment of the sheep fetus with a selective NPY-Y1 receptor antagonist does not affect the fetal cardiovascular response to acute moderate hypoxaemia. These results support a greater role for NPY in mediating the

  4. Mind over Matter: Reappraising Arousal Improves Cardiovascular and Cognitive Responses to Stress

    PubMed Central

    Jamieson, Jeremy P.; Nock, Matthew K.; Mendes, Wendy Berry

    2012-01-01

    Researchers have theorized that changing the way we think about our bodily responses can improve our physiological and cognitive reactions to stressful events. However, the underlying processes through which mental states improve downstream outcomes are not well-understood. To this end, we examined whether reappraising stress-induced arousal could improve cardiovascular outcomes and decrease attentional bias for emotionally-negative information. Participants were randomly assigned to either a reappraisal condition in which they were instructed to think about their physiological arousal during a stressful task as functional and adaptive, or to one of two control conditions: attention reorientation and no instructions. Relative to controls, participants instructed to reappraise their arousal exhibited more adaptive cardiovascular stress responses – increased cardiac efficiency and lower vascular resistance – and decreased attentional bias. Thus, reappraising arousal shows physiological and cognitive benefits. Implications for health and potential clinical applications are discussed. PMID:21942377

  5. Computational Models of the Cardiovascular System and Its Response to Microgravity

    NASA Technical Reports Server (NTRS)

    Kamm, Roger D.

    1999-01-01

    Computational models of the cardiovascular system are powerful adjuncts to ground-based and in-flight experiments. We will provide NSBRI with a model capable of simulating the short-term effects of gravity on cardiovascular function. The model from this project will: (1) provide a rational framework which quantitatively defines interactions among complex cardiovascular parameters and which supports the critical interpretation of experimental results and testing of hypotheses. (2) permit predictions of the impact of specific countermeasures in the context of various hypothetical cardiovascular abnormalities induced by microgravity. Major progress has been made during the first 18 months of the program: (1) We have developed an operational first-order computer model capable of simulating the cardiovascular response to orthostatic stress. The model consists of a lumped parameter hemodynamic model and a complete reflex control system. The latter includes cardiopulmonary and carotid sinus reflex limbs and interactions between the two. (2) We have modeled the physiologic stress of tilt table experiments and lower body negative pressure procedures (LBNP). We have verified our model's predictions by comparing them with experimental findings from the literature. (3) We have established collaborative efforts with leading investigators interested in experimental studies of orthostatic intolerance, cardiovascular control, and physiologic responses to space flight. (4) We have established a standardized method of transferring data to our laboratory from the ongoing NSBRI bedrest studies. We use this data to estimate input parameters to our model and compare our model predictions to actual data to further verify our model. (5) We are in the process of systematically simulating current hypotheses concerning the mechanism underlying orthostatic intolerance by matching our simulations to stand test data from astronauts pre- and post-flight. (6) We are in the process of developing a

  6. The influence of hostility and family history of cardiovascular disease on autonomic activation in response to controllable versus noncontrollable stress, anger imagery induction, and relaxation imagery.

    PubMed

    Nelson, Charles; Franks, Susan; Brose, Andrea; Raven, Peter; Williamson, Jon; Shi, Xiangrong; McGill, Jerry; Harrell, Ernest

    2005-06-01

    Autonomic activation in response to controllable versus noncontrollable stress, anger imagery induction, and relaxation imagery was studied among 80 participants between the ages of 18 and 34 years. Participants differed in level of trait hostility and family history of cardiovascular disease. Results were obtained through power spectral analyses of electrocardiograph R-R intervals, which produced an index of autonomic nervous system activation. For both male and female populations, parasympathetic regulation was diminished during anger induction for individuals with high levels of trait hostility and having a family history of cardiovascular disease. Similar results were obtained for women during the uncontrolled stress condition. Based on family history of cardiovascular disease and trait hostility, men responded differentially to relaxation imagery induction, whereas no differences were found among females. PMID:16015455

  7. Success importance and urge magnitude as determinants of cardiovascular response to a behavioral restraint challenge.

    PubMed

    Agtarap, Stephanie D; Wright, Rex A; Mlynski, Christopher; Hammad, Rawan; Blackledge, Sabrina

    2016-04-01

    Decades of research have investigated a conceptual analysis concerned with determinants and cardiovascular correlates of effort in people confronted with performance challenges, that is, opportunities to alter some course of events by acting. One suggestion is that effort and associated cardiovascular responses should be determined jointly by the difficulty of meeting a challenge and the importance of doing so. The present experiment tested this in a context involving behavioral restraint, that is, effortful resistance against a behavioral impulse or urge. Participants were presented a mildly evocative violent film clip (restraint difficulty low) or a strongly evocative violent film clip (restraint difficulty high) with instructions to refrain from showing any facial response. Success was made more or less important through coordinated manipulations of outcome expectancy, ego-involvement and social evaluation. As expected, SBP responses assessed during the work period were proportional to clip evocativeness - i.e., the difficulty of the restraint challenge - when importance was high, but low regardless of clip evocativeness when importance was low. Findings conceptually replicate previous cardiovascular results and support extension of the guiding analysis to the behavioral restraint realm. PMID:26968495

  8. Here we go again: bullying history and cardiovascular responses to social exclusion.

    PubMed

    Newman, Matthew L

    2014-06-22

    Previous research suggests that social exclusion-both acute and chronic-may be associated with a pattern of blunted cardiovascular responding. But it is unknown to what extent acute and chronic exclusion interact. That is, what happens when victims of long-term social rejection encounter an instance of exclusion later in life? The goal of the present study was to test whether prior experience being bullied would alter cardiovascular responses to an acute experience of social exclusion. Participants took part in a short online chat, during which they were either included or excluded from the conversation. Consistent with hypotheses, all participants showed an increase in sympathetic activity in the exclusion condition, but this response was significantly blunted among those with more chronic history of bullying victimization. No differences were observed for parasympathetic activity. This pattern suggests that a history of chronic victimization magnifies the cardiovascular "blunting" shown previously among victims of ostracism. This line of work suggests that bullying victims may develop regulatory mechanisms in response to social threats, and this may ultimately provide valuable information for helping victims become more resilient.

  9. The energetic and cardiovascular response to treadmill walking and cycle ergometer exercise in obese women.

    PubMed

    Lafortuna, Claudio L; Agosti, Fiorenza; Galli, Raffaela; Busti, Carlo; Lazzer, Stefano; Sartorio, Alessandro

    2008-08-01

    Physical activity is essential in obesity management, but exercise capacity is compromised in obese individuals due to the excessive body mass, impacting on body movement's energetics, and to the dysfunctions of regulatory mechanisms, affecting cardiovascular responses. This study aims to compare the energetics and cardiovascular responses of walking and cycling in obese women, and to formulate recommendations regarding the most suitable type of exercise for obesity. Fifteen obese (OB) and six normal weight (NW) women exercised on treadmill (TM) and cycle ergometer (CE). During both exercise modalities, metabolic rate was higher in OB than in NW and correlated with measures of body mass. Leg movement metabolic rate during cycling depended upon individual adiposity, and when accounted for, mechanical efficiency was similar in the two groups. When accounting for extra mass, differences in metabolic rate among groups are abolished for CE, indicating no obesity impairment of muscle efficiency, but not for TM, suggesting that differences in biomechanics may explain the higher net cost of transport of OB. In both groups, HR was higher during CE than TM at the same oxygen uptake (VO(2)), but in OB the HR increment over VO(2) was greater for CE than for TM. Therefore, due to different cardiovascular responses to TM and CE in OB, walking is more convenient, enabling OB to attain target energy expenditure at lower HR or in a shorter time.

  10. Cardiovascular responses to sustained maximal isometric contractions of the finger flexors.

    PubMed

    Smith, D L; Misner, J E; Bloomfield, D K; Essandoh, L K

    1993-01-01

    This study investigated cardiovascular responses to 2 min sustained submaximal (20% MVC) and maximal (100% MVC) voluntary isometric contractions of the finger flexors in healthy young women. Cardiovascular variables investigated were: heart rate (fc), mean arterial pressure (Pa), and stroke volume (SV). Doppler echocardiography was used to estimate SV from measures of aortic diameter (AD) and time-velocity integrals. Preliminary studies indicated that AD did not change significantly after 2 min sustained 100% MVC. Therefore, pre-exercise AD values were used to calculate SV before, during and after exercise. During the 2-min 100% MVC period, fc and Pa increased significantly during the first 30 s of contraction. fc then remained constant during the remainder of the 2-min contraction period, while Pa continued to rise. SV did not change significantly during the 100% MVC task but increased significantly during recovery from sustained 100% MVC. The data suggest that the magnitude of cardiovascular responses to isometric exercise is dependent on the specific task performed, and that there is a different pattern of response for fc, Pa, and SV during 20% and 100% MVC tasks. Unlike fc and Pa, SV did not change significantly during isometric exercise, but increased significantly after sustained 100% MVC. PMID:8375365

  11. Produced water exposure alters bacterial response to biocides.

    PubMed

    Vikram, Amit; Lipus, Daniel; Bibby, Kyle

    2014-11-01

    Microbial activity during the holding and reuse of wastewater from hydraulic fracturing operations, termed produced water, may lead to issues with corrosion, sulfide release, and fouling. Biocides are applied to control biological activity, often with limited efficacy, which is typically attributed to chemical interactions with the produced water. However, it is unknown whether there is a biologically driven mechanism to biocide tolerance in produced water. Here, we demonstrate that produced water exposure results in an enhanced tolerance against the typically used biocide glutaraldehyde and increased susceptibility to the oxidative biocide hypochlorite in a native and a model bacteria and that this altered resistance is due to the salinity of the produced water. In addition, we elucidate the genetic response of the model organism Pseudomonas fluorescens to produced water exposure to provide a mechanistic interpretation of the altered biocide resistance. The RNA-seq data demonstrated the induction of genes involved in osmotic stress, energy production and conversion, membrane integrity, and protein transport following produced water exposure, which facilitates bacterial survival and alters biocide tolerance. Efforts to fundamentally understand biocide resistance mechanisms, which enable the optimization of biocide application, hold significant implications for greening of the fracturing process through encouraging produced water recycling. Specifically, these results suggest the necessity of optimizing biocide application at the level of individual shale plays, rather than historical experience, based upon produced water characteristics and salinity. PMID:25279933

  12. The effects of various horse serum fractions in producing cardiovascular and renal lesions in rabbits.

    PubMed

    WISSLER, R W; SMULL, K; LESH, J B

    1949-12-01

    Five groups of 10 rabbits each were injected intravenously 2 times at 15 day intervals with either whole horse serum or one of its cold alcohol-precipitated fractions. Suitable serological and general observations were made at appropriate intervals before and after each injection. All animals were sacrificed on the 22nd day of the experiment. A study of the antemortem and pathological findings led to the following conclusions. 1. Allergie arteritis, valvulitis, and to a lesser degree, focal pericarditis, Aschoff-like nodules, and glomerulitis can be produced by several of the cold alcohol-precipitated fractions of horse serum as well as by whole serum. 2. Most of the acute arteritis was seen in rabbits receiving fraction V (albumin). These rabbits showed the largest amounts of circulating antigen, low antibody titers, low tissue sensitivity, and slight elevation in sedimentation rate and temperature. 3. There was a high incidence of chronic arteritis in the rabbits receiving fraction III which is almost devoid of albumin, suggesting that the alpha and beta globulins in addition to albumin may produce arteritis. 4. A state most nearly resembling that of acute rheumatic fever was produced by either fractions III or IV-3,4 (alpha and beta globulins). Pancarditis (pericarditis, Aschoff-like lesions, and valvulitis) was found relatively frequently. Many of the rabbits developed a high sedimentation rate, elevated temperature, and high tissue sensitivity, but little acute arteritis was found in this group. 5. Gamma globulin (fraction II) produced little reaction either in the antemortem determinations or histopathologically. 6. Glomerulitis of an acute necrotizing type was seen in a few rabbits without particular correlation to the fraction injected. 7. The frequency of involvement of heart valves in rabbit serum disease follows a pattern very similar to that of rheumatic heart disesae. 8. Attempts to correlate antemortem observations and pathological findings either on

  13. Network-based association of hypoxia-responsive genes with cardiovascular diseases

    NASA Astrophysics Data System (ADS)

    Wang, Rui-Sheng; Oldham, William M.; Loscalzo, Joseph

    2014-10-01

    Molecular oxygen is indispensable for cellular viability and function. Hypoxia is a stress condition in which oxygen demand exceeds supply. Low cellular oxygen content induces a number of molecular changes to activate regulatory pathways responsible for increasing the oxygen supply and optimizing cellular metabolism under limited oxygen conditions. Hypoxia plays critical roles in the pathobiology of many diseases, such as cancer, heart failure, myocardial ischemia, stroke, and chronic lung diseases. Although the complicated associations between hypoxia and cardiovascular (and cerebrovascular) diseases (CVD) have been recognized for some time, there are few studies that investigate their biological link from a systems biology perspective. In this study, we integrate hypoxia genes, CVD genes, and the human protein interactome in order to explore the relationship between hypoxia and cardiovascular diseases at a systems level. We show that hypoxia genes are much closer to CVD genes in the human protein interactome than that expected by chance. We also find that hypoxia genes play significant bridging roles in connecting different cardiovascular diseases. We construct a hypoxia-CVD bipartite network and find several interesting hypoxia-CVD modules with significant gene ontology similarity. Finally, we show that hypoxia genes tend to have more CVD interactors in the human interactome than in random networks of matching topology. Based on these observations, we can predict novel genes that may be associated with CVD. This network-based association study gives us a broad view of the relationships between hypoxia and cardiovascular diseases and provides new insights into the role of hypoxia in cardiovascular biology.

  14. Network-based association of hypoxia-responsive genes with cardiovascular diseases

    PubMed Central

    Wang, Rui-Sheng; Oldham, William M.; Loscalzo, Joseph

    2014-01-01

    Molecular oxygen is indispensable for cellular viability and function. Hypoxia is a stress condition in which oxygen demand exceeds supply. Low cellular oxygen content induces a number of molecular changes to activate regulatory pathways responsible for increasing the oxygen supply and optimizing cellular metabolism under limited oxygen conditions. Hypoxia plays critical roles in the pathobiology of many diseases, such as cancer, heart failure, myocardial ischemia, stroke, and chronic lung diseases. Although the complicated associations between hypoxia and cardiovascular (and cerebrovascular) diseases (CVD) have been recognized for some time, there are few studies that investigate their biological link from a systems biology perspective. In this study, we integrate hypoxia genes, CVD genes, and the human protein interactome in order to explore the relationship between hypoxia and cardiovascular diseases at a systems level. We show that hypoxia genes are much closer to CVD genes in the human protein interactome than that expected by chance. We also find that hypoxia genes play significant bridging roles in connecting different cardiovascular diseases. We construct an hypoxia-CVD bipartite network and find several interesting hypoxia-CVD modules with significant Gene Ontology (GO) similarity. Finally, we show that hypoxia genes tend to have more CVD interactors in the human interactome than in random networks of matching topology. Based on these observations, we can predict novel genes that may be associated with CVD. This network-based association study gives us a broad view of the relationships between hypoxia and cardiovascular diseases and provides new insights into the role of hypoxia in cardiovascular biology. PMID:25530704

  15. Spaceflight Did Not Impair Cardiovascular Responses to Upright Posture in an Elderly Astronaut

    NASA Technical Reports Server (NTRS)

    Rossum, Alfred C.; Ziegler, Michael G.; Meck, Janice V.

    2001-01-01

    Some of the cardiovascular changes associated with spaceflight have similarities to those associated with aging. We studied the neuroendocrine and hemodynamic responses to upright posture in a 77 year old astronaut before and after spaceflight and compared them to those of a group of 20 younger (41 plus or minus 1 years) astronauts. While arterial pressure responses to standing were similar between the young and old astronauts, hemodynamic profiles were quite different. The elderly astronaut achieved adequate standing arterial pressure primarily by maintaining stroke volume and thus cardiac output. In spite of very high norepinephrine release, he had very little increase in heart rate or total peripheral resistance. This pattern persisted on all test occasions. These responses suggest high sympathetic responses, down-regulated adrenergic receptors and decreased venous compliance typical of aging. In contrast, younger astronauts did not maintain stroke volume or cardiac output with standing, but had significant increases in heart rate and resistance. These results suggest that this elderly subject had cardiovascular responses to standing that are expected in an aged person. These responses were not deleteriously affected by spaceflight. We suggest that healthy, fit elderly individuals are able to withstand the stresses of extreme environments and are not necessarily limited in their activities simply due to their chronological age.

  16. Exposure to Maternal Gestational Diabetes Is Associated With Higher Cardiovascular Responses to Stress in Adolescent Indians

    PubMed Central

    Veena, Sargoor R.; Jones, Alexander; Srinivasan, Krishnamachari; Osmond, Clive; Karat, Samuel C.; Kurpad, Anura V.; Fall, Caroline H. D.

    2015-01-01

    Context: Altered endocrinal and autonomic nervous system responses to stress may link impaired intra-uterine growth with later cardiovascular disease. Objective: To test the hypothesis that offspring of gestational diabetic mothers (OGDM) have high cortisol and cardiosympathetic responses during the Trier Social Stress Test for Children (TSST-C). Design: Adolescents from a birth cohort in India (n = 213; mean age, 13.5 y), including 26 OGDM, 22 offspring of diabetic fathers (ODF), and 165 offspring of nondiabetic parents (controls) completed 5 minutes each of public speaking and mental arithmetic tasks in front of two unfamiliar “evaluators” (TSST-C). Salivary cortisol concentrations were measured at baseline and at regular intervals after the TSST-C. Heart rate, blood pressure (BP), stroke volume, cardiac output, and total peripheral resistance were measured continuously at baseline, during the TSST-C, and for 10 minutes after the test using a finger cuff; the beat-to-beat values were averaged for these periods. Results: Cortisol and cardiosympathetic parameters increased from baseline during stress (P < .001). OGDM had greater systolic BP (mean difference, 5.6 mm Hg), cardiac output (0.5 L/min), and stroke volume (4.0 mL) increases and a lower total peripheral resistance rise (125 dyn · s/cm5) than controls during stress. ODF had greater systolic BP responses than controls (difference, 4.1 mm Hg); there was no difference in other cardiosympathetic parameters. Cortisol responses were similar in all three groups. Conclusions: Maternal diabetes during pregnancy is associated with higher cardiosympathetic stress responses in the offspring, which may contribute to their higher cardiovascular disease risk. Further research may confirm stress-response programming as a predictor of cardiovascular risk in OGDM. PMID:25478935

  17. Adiposity is associated with blunted cardiovascular, neuroendocrine and cognitive responses to acute mental stress.

    PubMed

    Jones, Alexander; McMillan, Merlin R; Jones, Russell W; Kowalik, Grzegorz T; Steeden, Jennifer A; Deanfield, John E; Pruessner, Jens C; Taylor, Andrew M; Muthurangu, Vivek

    2012-01-01

    Obesity and mental stress are potent risk factors for cardiovascular disease but their relationship with each other is unclear. Resilience to stress may differ according to adiposity. Early studies that addressed this are difficult to interpret due to conflicting findings and limited methods. Recent advances in assessment of cardiovascular stress responses and of fat distribution allow accurate assessment of associations between adiposity and stress responsiveness. We measured responses to the Montreal Imaging Stress Task in healthy men (N = 43) and women (N = 45) with a wide range of BMIs. Heart rate (HR) and blood pressure (BP) measures were used with novel magnetic resonance measures of stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) and arterial compliance to assess cardiovascular responses. Salivary cortisol and the number and speed of answers to mathematics problems in the task were used to assess neuroendocrine and cognitive responses, respectively. Visceral and subcutaneous fat was measured using T(2) (*)-IDEAL. Greater BMI was associated with generalised blunting of cardiovascular (HR:β = -0.50 bpm x unit(-1), P = 0.009; SV:β = -0.33 mL x unit(-1), P = 0.01; CO:β = -61 mL x min(-1) x unit(-1), P = 0.002; systolic BP:β = -0.41 mmHg x unit(-1), P = 0.01; TPR:β = 0.11 WU x unit(-1), P = 0.02), cognitive (correct answers: r = -0.28, P = 0.01; time to answer: r = 0.26, P = 0.02) and endocrine responses (cortisol: r = -0.25, P = 0.04) to stress. These associations were largely determined by visceral adiposity except for those related to cognitive performance, which were determined by both visceral and subcutaneous adiposity. Our findings suggest that adiposity is associated with centrally reduced stress responsiveness. Although this may mitigate some long-term health risks of stress responsiveness, reduced performance under stress may be a more immediate

  18. Melatonin and Other Tryptophan Metabolites Produced by Yeasts: Implications in Cardiovascular and Neurodegenerative Diseases

    PubMed Central

    Hornedo-Ortega, Ruth; Cerezo, Ana B.; Troncoso, Ana M.; Garcia-Parrilla, M. Carmen; Mas, Albert

    2016-01-01

    Yeast metabolism produces compounds derived from tryptophan, which are found in fermented beverages, such as wine and beer. In particular, melatonin and serotonin, may be relevant due to their bioactivity in humans. Indeed, the former is a neurohormone related to circadian rhythms, which also has a putative protective effect against degenerative diseases. Moreover, serotonin is a neurotransmitter itself, in addition to being a precursor of melatonin synthesis. This paper summarizes data reported on fermented beverages, to evaluate dietary intake. Additionally, the article reviews observed effects of yeast amino acid metabolites on the prevention of neurodegenerative diseases (Alzheimer’s and Parkinson’s) and angiogenesis, focusing on evidence of the molecular mechanism involved and identification of molecular targets. PMID:26834716

  19. Cardiovascular, electrodermal, and respiratory response patterns to fear- and sadness-inducing films.

    PubMed

    Kreibig, Sylvia D; Wilhelm, Frank H; Roth, Walton T; Gross, James J

    2007-09-01

    Responses to fear- and sadness-inducing films were assessed using a broad range of cardiovascular (heart rate, T-wave amplitude, low- and high-frequency heart rate variability, stroke volume, preejection period, left-ventricular ejection time, Heather index, blood pressure, pulse amplitude and transit time, and finger temperature), electrodermal (level, response rate, and response amplitude), and respiratory (rate, tidal volume and its variability, inspiratory flow rate, duty cycle, and end-tidal pCO(2)) measures. Subjective emotional experience and facial behavior (Corrugator Supercilii and Zygomaticus Major EMG) served as control measures. Results indicated robust differential physiological response patterns for fear, sadness, and neutral (mean classification accuracy 85%). Findings are discussed in terms of the fight-flight and conservation-withdrawal responses and possible limitations of a valence-arousal categorization of emotion in affective space.

  20. Amygdalar neuronal activity mediates the cardiovascular responses evoked from the dorsolateral periaqueductal gray in conscious rats.

    PubMed

    de Abreu, A R; Abreu, A R; Santos, L T; de Souza, A A; da Silva, L G; Chianca, D A; de Menezes, R C

    2015-01-22

    There is ample evidence that both lateral/dorsolateral periaqueductal gray (l/dlPAG) and basolateral amygdala (BLA) are essential for the regulation of the autonomic responses evoked during innate reactions to threatening stimuli. However, it is not well established to what extent the BLA regulates the upstream functional connection from the l/dlPAG. Here we evaluated the role of the BLA and its glutamatergic receptors in the cardiovascular responses induced by l/dlPAG stimulation in rats. We examined the influence of acute inhibition of the BLA, unilaterally, by injecting muscimol on the cardiovascular responses evoked by the injection of N-methyl D-aspartate (NMDA) into the l/dlPAG. We also evaluated the role of BLA ionotropic glutamate receptors in these responses by injecting antagonists of NMDA and AMPA/kainate receptor subtypes into the BLA. Our results show that the microinjection of NMDA in the BLA increased the mean arterial pressure (MAP) and heart rate (HR). Injection of NMDA into the l/dlPAG caused similar increases in these variables, which was prevented by the prior injection of muscimol, a GABAA agonist, into the BLA. Moreover, injection of glutamatergic antagonists (2-amino-5-phosphonopentanoate (AP5) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)) into the BLA reduced the increase in MAP and HR induced by l/dlPAG activation. Finally, the inhibition of the central amygdala neurons failed to reduce the cardiovascular changes induced by l/dlPAG activation. These results indicate that physiological responses elicited by l/dlPAG activation require the neuronal activity in the BLA. This ascending excitatory pathway from the l/dlPAG to the BLA might ensure the expression of the autonomic component of the defense reaction. PMID:25451289

  1. Ambulatory monitoring of cardiovascular responses during behavioral modification of an aggressive dog.

    PubMed

    Williams, Nancy G; Borchelt, Peter L; Sollers, John J; Gasper, Peter W; Thayer, Julian F

    2003-01-01

    Previous work from our lab has used the Dutch Ambulatory Monitoring System (AMS) to assess the cardiovascular responses and motility of large free-ranging species (e.g. horses). To further examine the utility of using the AMS with non-humans, a study investigating the heart rate (HR) and heart period variability (HRV) of a large canine undergoing behavioral modification therapy was undertaken. This treatment emulated a restraint and tactile pressure technique that has previously been used in horses. Cardiovascular responses and motility were continuously measured pre-treatment (exposure to a stimulus dog), during treatment (in-box), and post-treatment. The treatment consisted of placing the dog in a 110 cm (long) by 45 cm (wide) by 102 cm (height) wooden box that only covered the animals' torso and legs and allowed the head to be free. Once the dog was in the box, the body was covered with a lightweight material (grain product) to effect restraint and tactile pressure, which was followed by a repeat exposure to the stimulus animal. Results indicated decreased heart rate and an increased HRV during the intervention as compared to baseline with indices of motility changing in the expected directions. Estimates of respiratory frequency derived from the autoregressive spectral analysis indicated changes in respiration did not account for the cardiovascular effects. In conclusion, tactile pressure and restraint may be an important tool for behavioral modification in both humans and animals, and the AMS is a useful tool for collecting cardiovascular data on a variety of species in a great many contexts. PMID:12724897

  2. Effect of an extruded pea or rice diet on postprandial insulin and cardiovascular responses in dogs.

    PubMed

    Adolphe, J L; Drew, M D; Silver, T I; Fouhse, J; Childs, H; Weber, L P

    2015-08-01

    Peas are increasing in popularity as a source of carbohydrate, protein and fibre in extruded canine diets. The aim of this study was to test the health effects of two canine diets with identical macronutrient profiles, but containing either yellow field peas or white rice as the carbohydrate source on metabolism, cardiovascular outcomes and adiposity. First, the acute glycemic, insulinemic and cardiovascular responses to the pea- or rice-based diets were determined in normal weight beagles (n = 7 dogs). The glycemic index did not differ between the pea diet (56 ± 12) and rice diet (63 ± 9). Next, obese beagles (n = 9) were fed the yellow field pea diet or white rice diet ad libitum for 12 weeks in a crossover study. Adiposity (measured using computed tomography), metabolic (oral glucose tolerance test, plasma leptin, adiponectin, C-reactive protein) and cardiovascular assessments (echocardiography and blood pressure) were performed before and after each crossover study period. After 12 weeks on each diet, peak insulin (p = 0.05) and area under the curve (AUC) for insulin after a 10 g oral glucose tolerance test (p = 0.05) were lower with the pea than the rice diet. Diet did not show a significant effect on body weight, fat distribution, cardiovascular variables, adiponectin or leptin. In conclusion, a diet containing yellow field peas reduced the postprandial insulin response after glucose challenge in dogs despite continued obesity, indicating improved metabolic health.

  3. Cardiovascular responses to microinjections of nicotine into the caudal ventrolateral medulla of the rat.

    PubMed

    Aberger, K; Chitravanshi, V C; Sapru, H N

    2001-02-16

    This study focuses on the role of nicotinic receptors located in the caudal ventrolateral medullary depressor area (CVLM) in regulating/modulating cardiovascular function. Blood pressure and heart rate were monitored by standard techniques in urethane-anesthetized, artificially ventilated, adult male Wistar rats. Multi-barreled glass-micropipettes (tip size 20-40 microm) were used to make microinjections (100 nl) into the CVLM. Concentrations of nicotine ranging from 250 micromto 10 mM were microinjected unilaterally into the CVLM. The maximum depressor and bradycardic responses were elicited by a 1 mM concentration of nicotine. Sequential microinjections of mecamylamine (1 mM), an antagonist for nicotinic receptors containing alpha3beta4 subunits, then alpha-bungarotoxin (1 microm), an antagonist for nicotinic receptors containing alpha-7 subunits, were made into the CVLM. Microinjecting a combination of a nicotinic receptor blocker and toxin resulted in the complete blockade of the cardiovascular responses induced by nicotine (1 mM, 100 nl). These results indicate that: (1) nicotinic receptors are present in the CVLM; (2) activation of these receptors results in depressor and bradycardic responses; (3) for a complete blockade of nicotine-induced cardiovascular responses, it is necessary to use a combination of mecamylamine and alpha-bungarotoxin; (4) since mecamylamine and alpha-bungarotoxin are known to block nicotinic receptors containing alpha3beta4 and alpha-7 subunits, respectively, two different subtypes of nicotinic receptors (one which contains a combination of alpha3beta4 subunits, and one which contains alpha-7 subunits) must be present in the CVLM; and (5) it is not clear whether these two subtypes of nicotinic receptor are located on the same or different populations of CVLM-neurons.

  4. Science, Ethics and the Climate Responsibilities of Industrial Carbon Producers

    NASA Astrophysics Data System (ADS)

    Frumhoff, P. C.

    2014-12-01

    The question of responsibility for climate change lies at the heart of societal debate over actions to curb greenhouse gas emissions and prepare for now unavoidable climate impacts. The UN Framework Convention on Climate Change established the principle of "common but differentiated responsibilities" among nations, signaling the recognition that industrialized nations who had produced the lion's share of historic emissions bore particular responsibility for avoiding dangerous interference with the climate system. But climate responsibilities can be distributed in other ways as well. This talk focuses on the scientific, historical and ethical basis for considering the climate responsibilities of the major fossil energy companies that have produced and marketed the coal, oil and natural gas whose use largely drives global warming, often while investing in efforts to discredit the scientific evidence and prevent policies that would encourage a transition to low-carbon energy. Earth scientists and scientific societies who rely on financial support from these companies have an opportunity to consider what ethical stance they might take to align their research, scientific understanding and values.

  5. Cardiovascular responses to postural changes: differences with age for women and men

    NASA Technical Reports Server (NTRS)

    Frey, M. A.; Tomaselli, C. M.; Hoffler, W. G.

    1994-01-01

    The cardiovascular responses to postural change, and how they are affected by aging, are inadequately described in women. Therefore, the authors examined the influence of age and sex on the responses of blood pressure, cardiac output, heart rate, and other variables to change in posture. Measurements were made after 10 minutes each in the supine, seated, and standing positions in 22 men and 25 women who ranged in age from 21 to 59 years. Several variables differed, both by sex and by age, when subjects were supine. On rising, subjects' diastolic and mean arterial pressures, heart rate, total peripheral resistance (TPR), and thoracic impedance increased; cardiac output, stroke volume, and mean stroke ejection rate decreased; and changes in all variables, except heart rate, were greater from supine to sitting than sitting to standing. The increase in heart rate was greater in the younger subjects, and increases in TPR and thoracic impedance were greater in the older subjects. Stroke volume decreased less, and TPR and thoracic impedance increased more, in the women than in the men. The increase in TPR was particularly pronounced in the older women. These studies show that the cardiovascular responses to standing differ, in some respects, between the sexes and with age. The authors suggest that the sex differences are, in part, related to greater decrease of thoracic blood volume with standing in women than in men, and that the age differences result, in part, from decreased responsiveness of the high-pressure baroreceptor system.

  6. Cardiovascular response to psychosocial repeated stress in caregivers of offspring with schizophrenia.

    PubMed

    González-Bono, Esperanza; de Andrés-Garcia, Sara; Romero-Martínez, Ángel; Moya-Albiol, Luis

    2013-01-01

    Taking care of offspring suffering a long-term illness such as schizophrenia is one of the more stressful life experiences. Care conditions may act as a protective factor in the health of the caregiver. The present study assesses heart rate (HR), blood pressure (BP), and mood responses to psychosocial stress in 16 mothers receiving specialised support for the care of their offspring (CARE+) and in 11 mothers caring for their offspring without support (CARE-). The CARE- group take care of less functional and more symptomatic offspring; and display higher basal, but lower HR, responses after stress than the CARE+ group. No significant group effects were found for BP. For mood states, there were significant decreases in the anger subscale in the CARE- group that were not found in the CARE+ group. HR was related to active and passive coping styles, trait anxiety, and years spent providing care. In the total sample, other significant relationships between cardiovascular responses and life events and personality traits have been found. In sum, the data suggests that specialised support for patients may modulate cardiovascular responses to repeated stress in caregivers.

  7. Rat Cardiovascular Responses to Whole Body Suspension: Head-down and Non-Head-Down Tilt

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.; Steffen, Joseph M.; Dombrowski, Judy

    1992-01-01

    The rat whole body suspension technique mimics responses seen during exposure to microgravity and was evaluated as a model for cardiovascular responses with two series of experiments. In one series, changes were monitored in chronically catheterized rats during 7 days of Head-Down Tilt (HDT) or Non-Head-Down Tilt (N-HDT) and after several hours of recovery. Elevations of mean arterial (MAP), systolic, and diastolic pressures of approx. 20 % (P less than 0.05) in HDT rats began as early as day 1 and were maintained for the duration of suspension. Pulse pressures were relatively unaffected, but heart rates were elevated approx. 10 %. During postsuspension (2-7 h), most cardiovascular parameters returned to presuspension levels. N-HDT rats exhibited elevations chiefly on days 3 and 7. In the second series, blood pressure was monitored in 1- and 3-day HDT and N-HDT rats to evaluate responses to rapid head-up tilt. MAP, systolic and diastolic pressures, and HR were elevated (P less than 0.05) in HDT and N-HDT rats during head-up tilt after 1 day of suspension, while pulse pressures remained un changed. HDT rats exhibited elevated pretilt MAP and failed to respond to rapid head-up tilt with further increase of MAP on day 3, indicating some degree of deconditioning. The whole body suspended rat may be useful as a model to better understand responses of rats exposed to microgravity.

  8. Covariation of phasic cortical and cardiovascular responses in a detection task.

    PubMed

    van der Veen, F M; Mulder, L J; Hoekzema, A; Mulder, G

    1996-10-31

    The relationship between cardiovascular and cortical responses was examined in an experiment in which subjects performed a detection task and a simple reference task. The detection task was developed according to Skinner et al., (1987). Cortical activity was examined with event related brain potentials (ERPs). ERPs revealed more cortical activation during detection task blocks. Both tonic and phasic measures of cardiovascular activity were derived. Tonic measures were heart rate (HR), systolic blood pressure (SBP). T-wave amplitude (TWA), respiration linked HR-variability and a measure for baroreflex sensitivity. These measures revealed no important differences between the reference task and detection task blocks. Phasic cardiovascular measures were evoked HR, SBP and TWA. Evoked HR showed a larger deceleration and evoked SBP showed a smaller decrease on detection task blocks. Evoked TWA did not differentiate between both types of task. It is concluded that an adjusted version of the fronto-cortical control hypothesis of Skinner could best account for the data. PMID:8913524

  9. Blockade of central vasopressin receptors reduces the cardiovascular response to acute stress in freely moving rats.

    PubMed

    Stojicić, S; Milutinović-Smiljanić, S; Sarenac, O; Milosavljević, S; Paton, J F R; Murphy, D; Japundzić-Zigon, N

    2008-04-01

    To investigate the contribution of central vasopressin receptors to blood pressure (BP) and heart rate (HR) response to stress we injected non-peptide selective V(1a) (SR49059), V(1b) (SSR149415), V(2) (SR121463) receptor antagonists, diazepam or vehicle in the lateral cerebral ventricle of conscious freely moving rats stressed by blowing air on their heads for 2 min. Cardiovascular effects of stress were evaluated by analyzing maximum increase of BP and HR (MAX), latency of maximum response (LAT), integral under BP and HR curve (integral), duration of their recovery and spectral parameters of BP and HR indicative of increased sympathetic outflow (LF(BP) and LF/HF(HR)). Moreover, the increase of serum corticosterone was measured. Exposure to air-jet stress induced simultaneous increase in BP and HR followed by gradual decline during recovery while LF(BP) oscillation remained increased as well as serum corticosterone level. Rats pre-treated with vasopressin receptor antagonists were not sedated while diazepam induced sedation that persisted during exposure to stress. V(1a), V(1b) and V(2) receptor antagonists applied separately did not modify basal values of cardiovascular parameters but prevented the increase in integral(BP). In addition, V(1b) and V(2) receptor antagonists reduced BP(MAX) whereas V(1a), V(1b) antagonist and diazepam reduced HR(MAX) induced by exposure to air-jet stress. All drugs shortened the recovery period, prevented the increase of LF(BP) without affecting the increase in serum corticosterone levels. Results indicate that vasopressin receptors located within the central nervous system mediate, in part, the cardiovascular response to air-jet stress without affecting either the neuroendocrine component or inducing sedation. They support the view that the V(1b) receptor antagonist may be of potential therapeutic value in reducing arterial pressure induced by stress-related disorders.

  10. Leptin in nucleus of the solitary tract alters the cardiovascular responses to aortic baroreceptor activation.

    PubMed

    Ciriello, John

    2013-06-01

    Recent data suggests that neurons expressing the long form of the leptin receptor form at least two distinct groups within the caudal nucleus of the solitary tract (NTS): a group within the lateral NTS (Slt) and one within the medial (Sm) and gelantinosa (Sg) NTS. Discrete injections of leptin into Sm and Sg, a region that receives chemoreceptor input, elicit increases in arterial pressure (AP) and renal sympathetic nerve activity (RSNA). However, the effect of microinjections of leptin into Slt, a region that receives baroreceptor input is unknown. Experiments were done in the urethane-chloralose anesthetized, paralyzed and artificially ventilated Wistar or Zucker obese rat to determine leptin's effect in Slt on heart rate (HR), AP and RSNA during electrical stimulation of the aortic depressor nerve (ADN). Depressor sites within Slt were first identified by the microinjection of l-glutamate (Glu; 0.25M; 10nl) followed by leptin microinjections. In the Wistar rat leptin microinjection (50ng; 20nl) into depressor sites within the lateral Slt elicited increases in HR and RSNA, but no changes in AP. Additionally, leptin injections into Slt prior to Glu injections at the same site or to stimulation of the ADN were found to attenuate the decreases in HR, AP and RSNA to both the Glu injection and ADN stimulation. In Zucker obese rats, leptin injections into NTS depressor sites did not elicit cardiovascular responses, nor altered the cardiovascular responses elicited by stimulation of ADN. Those data suggest that leptin acts at the level of NTS to alter the activity of neurons that mediate the cardiovascular responses to activation of the aortic baroreceptor reflex. PMID:23535030

  11. Leptin in nucleus of the solitary tract alters the cardiovascular responses to aortic baroreceptor activation.

    PubMed

    Ciriello, John

    2013-06-01

    Recent data suggests that neurons expressing the long form of the leptin receptor form at least two distinct groups within the caudal nucleus of the solitary tract (NTS): a group within the lateral NTS (Slt) and one within the medial (Sm) and gelantinosa (Sg) NTS. Discrete injections of leptin into Sm and Sg, a region that receives chemoreceptor input, elicit increases in arterial pressure (AP) and renal sympathetic nerve activity (RSNA). However, the effect of microinjections of leptin into Slt, a region that receives baroreceptor input is unknown. Experiments were done in the urethane-chloralose anesthetized, paralyzed and artificially ventilated Wistar or Zucker obese rat to determine leptin's effect in Slt on heart rate (HR), AP and RSNA during electrical stimulation of the aortic depressor nerve (ADN). Depressor sites within Slt were first identified by the microinjection of l-glutamate (Glu; 0.25M; 10nl) followed by leptin microinjections. In the Wistar rat leptin microinjection (50ng; 20nl) into depressor sites within the lateral Slt elicited increases in HR and RSNA, but no changes in AP. Additionally, leptin injections into Slt prior to Glu injections at the same site or to stimulation of the ADN were found to attenuate the decreases in HR, AP and RSNA to both the Glu injection and ADN stimulation. In Zucker obese rats, leptin injections into NTS depressor sites did not elicit cardiovascular responses, nor altered the cardiovascular responses elicited by stimulation of ADN. Those data suggest that leptin acts at the level of NTS to alter the activity of neurons that mediate the cardiovascular responses to activation of the aortic baroreceptor reflex.

  12. Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats

    PubMed Central

    Quagliotto, E.; Casali, K.R.; Dal Lago, P.; Rasia-Filho, A.A.

    2014-01-01

    The rat posterodorsal medial amygdala (MePD) links emotionally charged sensory stimuli to social behavior, and is part of the supramedullary control of the cardiovascular system. We studied the effects of microinjections of neuroactive peptides markedly found in the MePD, namely oxytocin (OT, 10 ng and 25 pg; n=6/group), somatostatin (SST, 1 and 0.05 μM; n=8 and 5, respectively), and angiotensin II (Ang II, 50 pmol and 50 fmol; n=7/group), on basal cardiovascular activity and on baroreflex- and chemoreflex-mediated responses in awake adult male rats. Power spectral and symbolic analyses were applied to pulse interval and systolic arterial pressure series to identify centrally mediated sympathetic/parasympathetic components in the heart rate variability (HRV) and arterial pressure variability (APV). No microinjected substance affected basal parameters. On the other hand, compared with the control data (saline, 0.3 µL; n=7), OT (10 ng) decreased mean AP (MAP50) after baroreflex stimulation and increased both the mean AP response after chemoreflex activation and the high-frequency component of the HRV. OT (25 pg) increased overall HRV but did not affect any parameter of the symbolic analysis. SST (1 μM) decreased MAP50, and SST (0.05 μM) enhanced the sympathovagal cardiac index. Both doses of SST increased HRV and its low-frequency component. Ang II (50 pmol) increased HRV and reduced the two unlike variations pattern of the symbolic analysis (P<0.05 in all cases). These results demonstrate neuropeptidergic actions in the MePD for both the increase in the range of the cardiovascular reflex responses and the involvement of the central sympathetic and parasympathetic systems on HRV and APV. PMID:25424367

  13. Structure response and damage produced by airblast from surface mining

    SciTech Connect

    Siskind, D.E.; Stachura, V.J.; Stagg, M.S.; Kopp, J.W.

    1980-01-01

    The Bureau of Mines studied airblast from surface mining to assess its damage and annoyance potential, and to determine safe levels and appropriate measurement techniques. Research results obtained from direct measurements of airblast-produced structure responses, damage, and analysis of instrument characteristics were combined with studies of sonic booms and human response to transient overpressures. Safe levels of airblast were found to be 134 db (0.1 Hz), 133 db (2 Hz), 129 db (6 Hz), and 105 db C-slow. These four airblast levels and measurement methods are equivalent in terms of structure response, and any one could be used as a safe-level criterion. Of the four methods, only the 0.1-Hz high-pass linear method accurately measures the total airblast energy present; however, the other three were found to adequately quantify the structure response and also represent techniques that are readily available to industry. Where a single airblast measuring system must be used, the 2-Hz linear peak response is the best overall compromise. The human response and annoyance problem from airblast is probably caused primarily by wall rattling and the resulting secondary noises. Although these will not entirely be precluded by the recommended levels, they are low enough to preclude damage to residential structures and any possible human injury over the long term.

  14. Effect of hindlimb suspension on cardiovascular responses to sympathomimetics and lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Overton, J. Michael; Tipton, Charles M.

    1990-01-01

    To determine whether hindlimb suspension is associated with the development of cardiovascular deconditioning, male rats were studied before and after undergoing one of three treatment conditions for 9 days: (1) cage control (n = 15, CON), (2) horizontal suspension (n = 15, HOZ), and (3) head-down suspension (n = 18, HDS). Testing included lower body negative pressure administered during chloralose-urethan anesthesia and graded doses of sympathomimetic agents (norepinephrine, phenylephrine, and tyramine) administered to conscious unrestrained animals. Both HDS and HOZ were associated with a small decrease in the hypotensive response to lower body negative pressure. The HOZ group, but not the HDS group, exhibited augmented reflex tachycardia. Furthermore, both HDS and HOZ groups manifested reduced pressor responses to phenylephrine after treatment. These reductions were associated with significantly attenuated increases in mesenteric vascular resistance. However, baroreflex control of heart rate was not altered by the treatment conditions. Collectively, these results indicate that 9 days of HDS in rats does not elicit hemodynamic response patterns generally associated with cardiovascular deconditioning induced by hypogravic conditions.

  15. Concord Grape Juice Polyphenols and Cardiovascular Risk Factors: Dose-Response Relationships

    PubMed Central

    Blumberg, Jeffrey B.; Vita, Joseph A.; Chen, C. -Y. Oliver

    2015-01-01

    Pure fruit juices provide nutritional value with evidence suggesting some of their benefits on biomarkers of cardiovascular disease risk may be derived from their constituent polyphenols, particularly flavonoids. However, few data from clinical trials are available on the dose-response relationship of fruit juice flavonoids to these outcomes. Utilizing the results of clinical trials testing single doses, we have analyzed data from studies of 100% Concord grape juice by placing its flavonoid content in the context of results from randomized clinical trials of other polyphenol-rich foods and beverages describing the same outcomes but covering a broader range of intake. We selected established biomarkers determined by similar methods for measuring flow-mediated vasodilation (FMD), blood pressure, platelet aggregation, and the resistance of low density lipoprotein cholesterol (LDL) to oxidation. Despite differences among the clinical trials in the treatment, subjects, and duration, correlations were observed between the dose and FMD. Inverse dose-response relationships, albeit with lower correlation coefficients, were also noted for the other outcomes. These results suggest a clear relationship between consumption of even modest serving sizes of Concord grape juice, flavonoid intake, and effects on risk factors for cardiovascular disease. This approach to dose-response relationships may prove useful for testing other individual foods and beverages. PMID:26633488

  16. Rat cardiovascular responses to whole body suspension - Head-down and non-head-down tilt

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.; Steffen, Joseph M.; Dombrowski, Judy

    1992-01-01

    Two experiments aimed at examining the versatility of the whole body suspension (WBS) system as a ground-based model for cardiovascular effects of microgravity are described. The first experiment studied heart rate and arterial pressure responses in rats during a 7-day period of head-down tilt (HDT) or nonhead-down tilt (NHDT) and after removal from whole body suspension (WBS). Mean arterial (MAP), systolic, and diastolic pressures increased about 20 percent in HDT rats on the fist day, heart rates were elevated about 10 percent. During postsuspension most cardiovascular parameters returned to presuspension levels. The second experiment evaluated responses to rapid head-up tilt in HDT and NHDT rats. It was observed that, while pulse pressures remained unchanged, MAP, systolic and diastolic pressures, and HR were elevated in HDT and NHDT rats during head-up tilt after one day of suspension. The WBS rats are considered to be useful as a model to better understand responses of rats exposed to microgravity.

  17. Concord Grape Juice Polyphenols and Cardiovascular Risk Factors: Dose-Response Relationships.

    PubMed

    Blumberg, Jeffrey B; Vita, Joseph A; Chen, C-Y Oliver

    2015-12-02

    Pure fruit juices provide nutritional value with evidence suggesting some of their benefits on biomarkers of cardiovascular disease risk may be derived from their constituent polyphenols, particularly flavonoids. However, few data from clinical trials are available on the dose-response relationship of fruit juice flavonoids to these outcomes. Utilizing the results of clinical trials testing single doses, we have analyzed data from studies of 100% Concord grape juice by placing its flavonoid content in the context of results from randomized clinical trials of other polyphenol-rich foods and beverages describing the same outcomes but covering a broader range of intake. We selected established biomarkers determined by similar methods for measuring flow-mediated vasodilation (FMD), blood pressure, platelet aggregation, and the resistance of low density lipoprotein cholesterol (LDL) to oxidation. Despite differences among the clinical trials in the treatment, subjects, and duration, correlations were observed between the dose and FMD. Inverse dose-response relationships, albeit with lower correlation coefficients, were also noted for the other outcomes. These results suggest a clear relationship between consumption of even modest serving sizes of Concord grape juice, flavonoid intake, and effects on risk factors for cardiovascular disease. This approach to dose-response relationships may prove useful for testing other individual foods and beverages.

  18. Effects of intracisternal administration of cannabidiol on the cardiovascular and behavioral responses to acute restraint stress.

    PubMed

    Granjeiro, Erica M; Gomes, Felipe V; Guimarães, Francisco S; Corrêa, Fernando M A; Resstel, Leonardo B M

    2011-10-01

    Systemic administration of cannabidiol (CBD), a non-psychotomimetic compound from Cannabis sativa, attenuates the cardiovascular and behavioral responses to restraint stress. Although the brain structures related to CBD effects are not entirely known, they could involve brainstem structures responsible for cardiovascular control. Therefore, to investigate this possibility the present study verified the effects of CBD (15, 30 and 60 nmol) injected into the cisterna magna on the autonomic and behavioral changes induced by acute restraint stress. During exposure to restraint stress (1h) there was a significant increase in mean arterial pressure (MAP) and heart rate (HR). Also, 24h later the animals showed a decreased percentage of entries onto the open arms of the elevated plus-maze. These effects were attenuated by CBD (30 nmol). The drug had no effect on MAP and HR baseline values. These results indicate that intracisternal administration of CBD can attenuate autonomic responses to stress. However, since CBD decreased the anxiogenic consequences of restraint stress, it is possible that the drug is also acting on forebrain structures. PMID:21771609

  19. Effects of whole-body cryotherapy duration on thermal and cardio-vascular response.

    PubMed

    Fonda, Borut; De Nardi, Massimo; Sarabon, Nejc

    2014-05-01

    Whole-body cryotherapy (WBC) is the exposure of minimally dressed participants to very cold air, either in a specially designed chamber (cryo-chamber) or cabin (cryo-cabin), for a short period of time. Practitioners are vague when it comes to recommendations on the duration of a single session. Recommended exposure for cryo-chamber is 150s, but no empirically based recommendations are available for a cryo-cabin. Therefore the aim of this study was to examine thermal and cardio-vascular responses after 90, 120, 150 and 180s of WBC in a cryo-cabin. Our hypothesis was that skin temperature would be significantly lower after longer exposers. Twelve male participants (age 23.9±4.2 years) completed four WBC of different durations (90, 120, 150 and 180s) in a cryo-cabin. Thermal response, heart rate and blood pressure were measured prior, immediately after, 5min after and 30min after the session. Skin temperature differed significantly among different durations, except between 150 and 180s. There was no significant difference in heart rate and blood pressure. Thermal discomfort during a single session displayed a linear increase throughout the whole session. Our results indicate that practitioners and clinicians using cryo-cabin for WBC do not need to perform sessions longer than 150s. We have shown that longer sessions do not substantially affect thermal and cardio-vascular response, but do increase thermal discomfort. PMID:24802149

  20. Chemosensitivity, Cardiovascular Risk, and the Ventilatory Response to Exercise in COPD

    PubMed Central

    Stickland, Michael K.; Fuhr, Desi P.; Edgell, Heather; Byers, Brad W.; Bhutani, Mohit; Wong, Eric Y. L.; Steinback, Craig D.

    2016-01-01

    COPD is associated with elevated cardiovascular risk and a potentiated ventilatory response to exercise. Enhanced carotid chemoreceptor (CC) activity/sensitivity is present in other clinical conditions, has been shown to contribute to sympathetic vasoconstrictor outflow, and is predictive of mortality. CC activity/sensitivity, and the resulting functional significance, has not been well examined in COPD. We hypothesized that CC activity/sensitivity would be elevated in COPD, and related to increased pulse wave velocity (a marker of CV risk) and the ventilatory response to exercise. Methods: 30 COPD patients and 10 healthy age-matched controls were examined. Participants performed baseline cardiopulmonary exercise and pulmonary function testing. CC activity was later evaluated by the drop in ventilation with breathing 100% O2, and CC sensitivity was then assessed by the ventilatory response to hypoxia (ΔVE/ΔSpO2). Peripheral arterial stiffness was subsequently evaluated by measurement of pulse wave velocity (PWV) using applanation tonometry while the subjects were breathing room air, and then following chemoreceptor inhibition by breathing 100% O2 for 2 minutes. Results: CC activity, CC sensitivity, PWV and the ventilatory response to exercise were all increased in COPD relative to controls. CC sensitivity was related to PWV; however, neither CC activity nor CC sensitivity was related to the ventilatory response to exercise in COPD. CC inhibition by breathing 100% O2 normalized PWV in COPD, while no effect was observed in controls. Conclusion: CC activity and sensitivity are elevated in COPD, and appear related to cardiovascular risk; however, CC activity/sensitivity does not contribute to the potentiated ventilatory response to exercise. PMID:27355356

  1. The effect of blood volume loss on cardiovascular response to lower body negative pressure using a mathematical model

    NASA Technical Reports Server (NTRS)

    Karam, E. H.; Srinivasan, R. S.; Charles, J. B.; Fortney, S. M.

    1994-01-01

    Different mathematical models of varying complexity have been proposed in recent years to study the cardiovascular (CV) system. However, only a few of them specifically address the response to lower body negative pressure (LBNP), a stress that can be applied in weightlessness to predict changes in orthostatic tolerance. Also, the simulated results produced by these models agree only partially with experimental observations. In contrast, the model proposed by Melchior et al., and modified by Karam et al. is a simple representation of the CV system capable of accurately reproducing observed LBNP responses up to presyncopal levels. There are significant changes in LBNP response due to a loss of blood volume and other alterations that occur in weightlessness and related one-g conditions such as bedrest. A few days of bedrest can cause up to 15% blood volume loss (BVL), with consequent decreases in both stroke volume and cardiac output, and increases in heart rate, mean arterial pressure, and total peripheral resistance. These changes are more pronounced at higher levels of LBNP. This paper presents the results of a simulation study using our CV model to examine the effect of BVL on LBNP response.

  2. Angiotensin II modulates the cardiovascular responses to microinjection of NPY Y1 and NPY Y2 receptor agonists into the nucleus tractus solitarii of the rat.

    PubMed

    Díaz-Cabiale, Zaida; Fuxe, Kjell; Coveñas, Rafael; González-Barón, Salvador; Narváez, José A

    2003-09-01

    The aim of this work was to investigate the modulation of the cardiovascular effects of neuropeptide Y (NPY) in the nucleus tractus solitarii (NTS) by angiotensin II (Ang II) and to determine the NPY receptor subtype involved in this modulation. Anesthesized Sprague-Dawley rats received microinjections in the NTS of Ang II (threshold and ED(50) doses) with NPY Y(1) agonist Leu(31)Pro(34)NPY and NPY Y(2) agonist NPY(13-36) (threshold and ED(50) doses). The changes in mean arterial pressure (MAP) and heart rate (HR) recorded in the femoral artery were analyzed during 60 min after the microinjections. The injection of threshold doses of Ang II, Y(1) agonist or Y(2) agonist alone did not produce any change in cardiovascular parameters. However, the co-injections into the NTS of threshold doses of both Ang II and the Y(1) agonist elicited significant increases of MAP and HR of about 12 and 10%, respectively. The co-administration of threshold doses of Ang II with the Y(2) agonist also induced a significant vasopressor response. The vasodepressor and bradycardiac effect of an ED(50) dose of the Y(1) agonist was significantly counteracted (P<0.01) by a threshold dose of Ang II. The vasopressor effect elicited by an ED(50) dose of the Y(2) agonist was significantly enhanced by a threshold dose of Ang II (P<0.01). No significant change of cardiovascular responses elicited by an ED(50) dose of Ang II was observed in the presence of threshold doses of the Y(1) agonist or of the Y(2) agonist. The present study gives functional evidences for a differential modulatory activity of Ang II on the cardiovascular responses mediated by Y(1) and Y(2) receptor subtypes, which may be of relevance for central cardiovascular regulation in the NTS.

  3. Cardiovascular and cerebrovascular effects in response to red bull consumption combined with mental stress.

    PubMed

    Grasser, Erik Konrad; Dulloo, Abdul G; Montani, Jean-Pierre

    2015-01-15

    The sale of energy drinks is often accompanied by a comprehensive and intense marketing with claims of benefits during periods of mental stress. As it has been shown that Red Bull negatively impacts human hemodynamics at rest, we investigated the cardiovascular and cerebrovascular consequences when Red Bull is combined with mental stress. In a randomized cross-over study, 20 young healthy humans ingested either 355 ml of a can Red Bull or water and underwent 80 minutes after the respective drink a mental arithmetic test for 5 minutes. Continuous cardiovascular and cerebrovascular recordings were performed for 20 minutes before and up to 90 minutes after drink ingestion. Measurements included beat-to-beat blood pressure (BP), heart rate, stroke volume, and cerebral blood flow velocity. Red Bull increased systolic BP (+7 mm Hg), diastolic BP (+4 mm Hg), and heart rate (+7 beats/min), whereas water drinking had no significant effects. Cerebral blood flow velocity decreased more in response to Red Bull than to water (-9 vs -3 cm/s, p <0.005). Additional mental stress further increased both systolic BP and diastolic BP (+3 mm Hg, p <0.05) and heart rate (+13 beats/min, p <0.005) in response to Red Bull; similar increases were also observed after water ingestion. In combination, Red Bull and mental stress increased systolic BP by about 10 mm Hg, diastolic BP by 7 mm Hg, and heart rate by 20 beats/min and decreased cerebral blood flow velocity by -7 cm/s. In conclusion, the combination of Red Bull and mental stress impose a cumulative cardiovascular load and reduces cerebral blood flow even under a mental challenge.

  4. Human cardiovascular response to sympathomimetic agents during head-down bed rest: the effect of dietary sodium

    NASA Technical Reports Server (NTRS)

    Williams, W. J.; Stuart, C. A.; Fortney, S. M.; Pietrzyk, R. A.; Chen, Y. M.; Whitson, P. A.

    1994-01-01

    Changes in sympathoadrenal function and cardiovascular deconditioning have long been recognized as a feature of the physiological adaptation to microgravity. The deconditioning process, coupled with altered hydration status, is thought to significantly contribute to orthostatic intolerance upon return to Earth gravity. The cardiovascular response to stimulation by sympathomimetic agents before, during, and after exposure to simulated microgravity was determined in healthy volunteers equilibrated on normal or high sodium diets in order to further the understanding of the deconditioning process.

  5. Exaggerated sympathetic and cardiovascular responses to stimulation of the mesencephalic locomotor region in spontaneously hypertensive rats.

    PubMed

    Liang, Nan; Mitchell, Jere H; Smith, Scott A; Mizuno, Masaki

    2016-01-01

    The sympathetic and pressor responses to exercise are exaggerated in hypertension. However, the underlying mechanisms causing this abnormality remain to be fully elucidated. Central command, a neural drive originating in higher brain centers, is known to activate cardiovascular and locomotor control circuits concomitantly. As such, it is a viable candidate for the generation of the augmented vascular response to exercise in this disease. We hypothesized that augmentations in central command function contribute to the heightened cardiovascular response to exercise in hypertension. To test this hypothesis, changes in renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) in response to electrical stimulation of mesencephalic locomotor region (MLR; 20-50 μA in 10-μA steps evoking fictive locomotion), a putative component of the central command pathway, were examined in decerebrate, paralyzed normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Tibial nerve discharge during MLR stimulation significantly increased in an intensity-dependent manner in both WKY and SHR but was not different between groups. Stimulation of the MLR evoked significantly larger increases in RSNA and MAP with increasing stimulation intensity in both groups. Importantly, the increases in sympathetic and pressor responses to this fictive locomotion were significantly greater in SHR compared with WKY across all stimulation intensities (e.g., at 50 μA, ΔRSNA: WKY 153 ± 31%, SHR 287 ± 42%; ΔMAP: WKY 87 ± 9 mmHg, SHR 139 ± 7 mmHg). These findings provide the first evidence that central command may be a critical contributor to the exaggerated rise in sympathetic activity and blood pressure during exercise in hypertension. PMID:26545711

  6. Effects of thyroid hormone on. beta. -adrenergic responsiveness of aging cardiovascular systems

    SciTech Connect

    Tsujimoto, G.; Hashimoto, K.; Hoffman, B.B.

    1987-03-01

    The authors have compared the effects of ..beta..-adrenergic stimulation on the heart and peripheral vasculature of young (2-mo-old) and older (12-mo-old) rats both in the presence and absence of triiodothyronine (T/sub 3/)-induced hyperthyroidism. The hemodynamic consequences of T/sub 3/ treatment were less prominent in the aged hyperthyroid rats compared with young hyperthyroid rats (both in intact and pithed rats). There was a decrease in sensitivity of chronotropic responsiveness to isoproterenol in older pithed rats, which was apparently reversed by T/sub 3/ treatment. The number and affinity of myocardial ..beta..-adrenergic receptor sites measured by (/sup 125/I)cyanopindolol were not significantly different in young and older control rats; also, ..beta..-receptor density increased to a similar extent in both young and older T/sub 3/-treated rats. The ability of isoproterenol to relax mesenteric arterial rings, markedly blunted in older rats, was partially restored by T/sub 3/ treatment without their being any change in isoproterenol-mediated relaxation in the arterial preparation from young rats. The number and affinity of the ..beta..-adrenergic receptors measured in the mesenteric arteries was unaffected by either aging or T/sub 3/ treatment. The data suggest that effects of thyroid hormone and age-related alterations of cardiovascular responsiveness to ..beta..-adrenergic stimulation are interrelated in a complex fashion with a net result that the hyperkinetic cardiovascular manifestations in hyperthyroidism are attenuated in the older animals.

  7. Acute cardiovascular responses while playing virtual games simulated by Nintendo Wii®

    PubMed Central

    Rodrigues, Gusthavo Augusto Alves; Felipe, Danilo De Souza; Silva, Elisangela; De Freitas, Wagner Zeferino; Higino, Wonder Passoni; Da Silva, Fabiano Fernandes; De Carvalho, Wellington Roberto Gomes; Aparecido de Souza, Renato

    2015-01-01

    [Purpose] This investigation evaluated the acute cardiovascular responses that occur while playing virtual games (aerobic and balance) emulated by Nintendo Wii®. [Subjects] Nineteen healthy male volunteers were recruited. [Methods] The ergospirometric variables of maximum oxygen consumption, metabolic equivalents, and heart rate were obtained during the aerobic (Obstacle Course, Hula Hoop, and Free Run) and balance (Soccer Heading, Penguin Slide, and Table Tilt) games of Wii Fit Plus® software. To access and analyze the ergospirometric information, a VO2000 analyzer was used. Normalized data (using maximum oxygen consumption and heart rate) were analyzed using repeated measures analysis of variance and Scheffe’s test. [Results] Significant differences were found among the balance and aerobic games in all variables analyzed. In addition, the Wii exercises performed were considered to be of light (balance games) and moderate (aerobic games) intensity in accordance with American College Sports Medicine exercise stratification. [Conclusion] Physical activity in a virtual environment emulated by Nintendo Wii® can change acute cardiovascular responses, primarily when Wii aerobic games are performed. These results support the use of the Nintendo Wii® in physical activity programs. PMID:26504308

  8. Acute cardiovascular responses while playing virtual games simulated by Nintendo Wii(®).

    PubMed

    Rodrigues, Gusthavo Augusto Alves; Felipe, Danilo De Souza; Silva, Elisangela; De Freitas, Wagner Zeferino; Higino, Wonder Passoni; Da Silva, Fabiano Fernandes; De Carvalho, Wellington Roberto Gomes; Aparecido de Souza, Renato

    2015-09-01

    [Purpose] This investigation evaluated the acute cardiovascular responses that occur while playing virtual games (aerobic and balance) emulated by Nintendo Wii(®). [Subjects] Nineteen healthy male volunteers were recruited. [Methods] The ergospirometric variables of maximum oxygen consumption, metabolic equivalents, and heart rate were obtained during the aerobic (Obstacle Course, Hula Hoop, and Free Run) and balance (Soccer Heading, Penguin Slide, and Table Tilt) games of Wii Fit Plus(®) software. To access and analyze the ergospirometric information, a VO2000 analyzer was used. Normalized data (using maximum oxygen consumption and heart rate) were analyzed using repeated measures analysis of variance and Scheffe's test. [Results] Significant differences were found among the balance and aerobic games in all variables analyzed. In addition, the Wii exercises performed were considered to be of light (balance games) and moderate (aerobic games) intensity in accordance with American College Sports Medicine exercise stratification. [Conclusion] Physical activity in a virtual environment emulated by Nintendo Wii(®) can change acute cardiovascular responses, primarily when Wii aerobic games are performed. These results support the use of the Nintendo Wii(®) in physical activity programs.

  9. Cardiovascular responses to exercise as functions of absolute and relative work load

    NASA Technical Reports Server (NTRS)

    Lewis, S. F.; Taylor, W. F.; Graham, R. M.; Pettinger, W. A.; Schutte, J. E.; Blomqvist, C. G.

    1983-01-01

    The roles of absolute and relative oxygen uptake (VO2 and percent of muscle group specific VO2-max) as determinants of the cardiovascular and ventilatory responses to exercise over a wide range of active muscle mass are investigated. Experiments were conducted using four types of dynamic exercise: one-arm curl, one-arm cranking, and one and two-leg cycling at four different relative work loads (25, 50, 75, and 100 percent of VO2-max) for the corresponding muscle group. Results show that VO2 during maximal one-arm curl, one-arm cranking, and one-leg cycling averaged 20, 50, and 75 percent, respectively, of that for maximal two-leg cycling. Cardiac output was determined to be linearly related to VO2 with a similar slope and intercept for each type of exercise, and the heart rate at a given percent VO2-max was higher with larger active muscle mass. It is concluded that the cardiovascular responses to exercise was determined to a large extent by the active muscle mass and the absolute oxygen uptake, with the principal feature appearing to be the tight linkage between systematic oxygen transport and utilization.

  10. Role of autonomic reflex arcs in cardiovascular responses to air pollution exposure.

    PubMed

    Perez, Christina M; Hazari, Mehdi S; Farraj, Aimen K

    2015-01-01

    The body responds to environmental stressors by triggering autonomic reflexes in the pulmonary receptors, baroreceptors, and chemoreceptors to maintain homeostasis. Numerous studies have shown that exposure to various gases and airborne particles can alter the functional outcome of these reflexes, particularly with respect to the cardiovascular system. Modulation of autonomic neural input to the heart and vasculature following direct activation of sensory nerves in the respiratory system, elicitation of oxidative stress and inflammation, or through other mechanisms is one of the primary ways that exposure to air pollution affects normal cardiovascular function. Any homeostatic process that utilizes the autonomic nervous system to regulate organ function might be affected. Thus, air pollution and other inhaled environmental irritants have the potential to alter both local airway function and baro- and chemoreflex responses, which modulate autonomic control of blood pressure and detect concentrations of key gases in the body. While each of these reflex pathways causes distinct responses, the systems are heavily integrated and communicate through overlapping regions of the brainstem to cause global effects. This short review summarizes the function of major pulmonary sensory receptors, baroreceptors, and carotid body chemoreceptors and discusses the impacts of air pollution exposure on these systems.

  11. Acute cardiovascular responses while playing virtual games simulated by Nintendo Wii(®).

    PubMed

    Rodrigues, Gusthavo Augusto Alves; Felipe, Danilo De Souza; Silva, Elisangela; De Freitas, Wagner Zeferino; Higino, Wonder Passoni; Da Silva, Fabiano Fernandes; De Carvalho, Wellington Roberto Gomes; Aparecido de Souza, Renato

    2015-09-01

    [Purpose] This investigation evaluated the acute cardiovascular responses that occur while playing virtual games (aerobic and balance) emulated by Nintendo Wii(®). [Subjects] Nineteen healthy male volunteers were recruited. [Methods] The ergospirometric variables of maximum oxygen consumption, metabolic equivalents, and heart rate were obtained during the aerobic (Obstacle Course, Hula Hoop, and Free Run) and balance (Soccer Heading, Penguin Slide, and Table Tilt) games of Wii Fit Plus(®) software. To access and analyze the ergospirometric information, a VO2000 analyzer was used. Normalized data (using maximum oxygen consumption and heart rate) were analyzed using repeated measures analysis of variance and Scheffe's test. [Results] Significant differences were found among the balance and aerobic games in all variables analyzed. In addition, the Wii exercises performed were considered to be of light (balance games) and moderate (aerobic games) intensity in accordance with American College Sports Medicine exercise stratification. [Conclusion] Physical activity in a virtual environment emulated by Nintendo Wii(®) can change acute cardiovascular responses, primarily when Wii aerobic games are performed. These results support the use of the Nintendo Wii(®) in physical activity programs. PMID:26504308

  12. Difficulty, effort and cardiovascular response to a working memory challenge: Older adults with and without mild cognitive impairment.

    PubMed

    Stewart, Christopher C; Wright, Rex A; Griffith, H Randall

    2016-06-01

    We presented cognitively healthy older adults and patients with mild cognitive impairment (MCI) three versions of a modified Sternberg memory task designed to range in difficulty from low to high. Among cognitively healthy older adults, blood pressure responses assessed during the work periods rose with difficulty. By contrast, among MCI patients, blood pressure responses assessed during the work periods were low irrespective of difficulty. Findings are discussed primarily in relation to a conceptual analysis concerned with ability determinants of effort (task engagement) and associated cardiovascular responses. They also are discussed in the context of other recent cardiovascular studies involving older adults and with regard to the potential for exaggerated cardiovascular responses to accelerate cognitive decline in advanced age. PMID:27109608

  13. Glucose-responsive insulin-producing cells from stem cells.

    PubMed

    Kaczorowski, David J; Patterson, Ethan S; Jastromb, William E; Shamblott, Michael J

    2002-01-01

    Recent success with immunosuppression following islet cell transplantation offers hope that a cell transplantation treatment for type 1 (juvenile) diabetes may be possible if sufficient quantities of safe and effective cells can be produced. For the treatment of type 1 diabetes, the two therapeutically essential functions are the ability to monitor blood glucose levels and the production of corresponding and sufficient levels of mature insulin to maintain glycemic control. Stem cells can replicate themselves and produce cells that take on more specialized functions. If a source of stem cells capable of yielding glucose-responsive insulin-producing (GRIP) cells can be identified, then transplantation-based treatment for type 1 diabetes may become widely available. Currently, stem cells from embryonic and adult sources are being investigated for their ability to proliferate and differentiate into cells with GRIP function. Human embryonic pluripotent stem cells, commonly referred to as embryonic stem (ES) cells and embryonic germ (EG) cells, have received significant attention owing to their broad capacity to differentiate and ability to proliferate well in culture. Their application to diabetes research is of particular promise, as it has been demonstrated that mouse ES cells are capable of producing cells able to normalize glucose levels of diabetic mice, and human ES cells can differentiate into cells capable of insulin production. Cells with GRIP function have also been derived from stem cells residing in adult organisms, here referred to as endogenous stem cell sources. Independent of source, stem cells capable of producing cells with GRIP function may provide a widely available cell transplantation treatment for type 1 diabetes. PMID:12469358

  14. Assessment of cardiovascular response to treadmill exercise in normal healthy Indian adolescents.

    PubMed

    Pande, Sushma S; Pande, Santosh R; Dhore, Rajendra B; Daphale, Ajay V; Parate, Vrushali R; Patel, Shishir S; Agrekar, Sushil H

    2012-01-01

    The study aims to assess the cardiovascular response to treadmill exercise test in healthy Indian adolescents. A group of 50 healthy adolescents took part in the study. Cardiovascular response was assessed by using treadmill exercise test as per Bruce protocol. Pulse rate, blood pressure and ECG were recorded before, during and after undertaking the treadmill test. Mean age and body mass index (BMI) were 18.7 +/- 0.51 yrs. and 21.4 +/- 3.44 kg/m2 respectively. Karl Pearson Correlation analysis showed highly significant negative correlation between BMI and exercise time (r = -0.598, P<0.001) and between resting DBP and Exercise Time (r = -0.424, P<0.002). While BMI and DBP showed highly significant positive correlation (r = 0.463, P<0.001). During exercise pulse and SBP rose and DBP fell. SBP rose from mean 122 to 175 (rise by 53 mm of Hg) and DBP fell from mean 78 to 65 (fall by 13 mm of Hg). One min recovery pulse was 156 indicating 22% fall from target heart rate. All the parameters returned to near resting value at 6 min recovery. In 30% students DBP showed exaggerated response i.e. rise during exercise. These students had more BMI and higher resting DBP as compared to other students, which could be the reason for exaggerated response in these participants. In ECG there were no significant ST/T changes during exercise or recovery period. This study provides normal data for small sample of healthy Indian adolescents when subjected to treadmill exercise test. PMID:23029962

  15. Malnutrition alters the cardiovascular responses induced by central injection of tityustoxin in Fischer rats.

    PubMed

    Silva, Fernanda Cacilda Santos; Guidine, Patrícia Alves; Ribeiro, Mara Fernandes; Fernandes, Luciano Gonçalves; Xavier, Carlos Henrique; de Menezes, Rodrigo Cunha; Silva, Marcelo Eustáquio; Moraes-Santos, Tasso; Moraes, Márcio Flávio; Chianca, Deoclécio Alves

    2013-12-15

    Scorpion envenoming and malnutrition are considered two important public health problems in Brazil, involving mainly children. Both these conditions are more common among the economically stratified lower income portion of the population, thus suggesting that these factors should be analyzed concomitantly. It is known that cardiorespiratory manifestations, as cardiac arrhythmias, arterial hypertension and hypotension, pulmonary edema and circulatory failure are the main "causa mortis" of scorpion envenomation. Additionally, there are evidences in the literature that deficiencies in dietary intake endanger the CNS and modify the cardiovascular homeostasis. Then, the objective of this work is to evaluate the protein malnourished effect on cardiovascular responses induced by tityustoxin (TsTX, an α-type toxin extracted from the Tityus serrulatus scorpion venom). Fischer rats (n = 20) were injected i.c.v. with TsTX and divided in control and malnorished groups, which were, respectively, submitted to a control and a low-protein diet. Arterial pressure recordings were done until death of the animals. Although both groups presented an increased mean arterial pressure after TsTX injection, this increase was smaller and delayed in malnourished rats, when compared to control rats. In addition, heart rate increased only in rats from the control group. Finally, malnourished rats had an increase in survival time (9:9/13.5 vs. 15.5:10.5/18 min; p = 0.0009). In summary, our results suggest that the protein restriction attenuates the cardiovascular manifestations resulting from TsTX action on CNS. PMID:24060375

  16. Acrolein inhalation alters arterial blood gases and triggers carotid body-mediated cardiovascular responses in hypertensive rats

    PubMed Central

    Perez, Christina M.; Hazari, Mehdi S.; Ledbetter, Allen D.; Haykal-Coates, Najwa; Carll, Alex P.; Cascio, Wayne E.; Winsett, Darrell W.; Costa, Daniel L.; Farraj, Aimen K.

    2016-01-01

    Context Air pollution exposure affects autonomic function, heart rate, blood pressure and left ventricular function. While the mechanism for these effects is uncertain, several studies have reported that air pollution exposure modifies activity of the carotid body, the major organ that senses changes in arterial oxygen and carbon dioxide levels, and elicits downstream changes in autonomic control and cardiac function. Objective We hypothesized that exposure to acrolein, an unsaturated aldehyde and mucosal irritant found in cigarette smoke and diesel exhaust, would activate the carotid body chemoreceptor response and lead to secondary cardiovascular responses in rats. Materials and methods Spontaneously hypertensive (SH) rats were exposed once for 3 h to 3 ppm acrolein gas or filtered air in whole body plethysmograph chambers. To determine if the carotid body mediated acrolein-induced cardiovascular responses, rats were pretreated with an inhibitor of cystathionine γ-lyase (CSE), an enzyme essential for carotid body signal transduction. Results Acrolein exposure induced several cardiovascular effects. Systolic, diastolic and mean arterial blood pressure increased during exposure, while cardiac contractility decreased 1 day after exposure. The cardiovascular effects were associated with decreases in pO2, breathing frequency and expiratory time, and increases in sympathetic tone during exposure followed by parasympathetic dominance after exposure. The CSE inhibitor prevented the cardiovascular effects of acrolein exposure. Discussion and conclusion Pretreatment with the CSE inhibitor prevented the cardiovascular effects of acrolein, suggesting that the cardiovascular responses with acrolein may be mediated by carotid body-triggered changes in autonomic tone. (This abstract does not reflect EPA policy.) PMID:25600140

  17. Analysis of cardiovascular responses to the H2S donors Na2S and NaHS in the rat

    PubMed Central

    Yoo, Daniel; Jupiter, Ryan C.; Pankey, Edward A.; Reddy, Vishwaradh G.; Edward, Justin A.; Swan, Kevin W.; Peak, Taylor C.; Mostany, Ricardo

    2015-01-01

    Hydrogen sulfide (H2S) is an endogenous gaseous molecule formed from L-cysteine in vascular tissue. In the present study, cardiovascular responses to the H2S donors Na2S and NaHS were investigated in the anesthetized rat. The intravenous injections of Na2S and NaHS 0.03–0.5 mg/kg produced dose-related decreases in systemic arterial pressure and heart rate, and at higher doses decreases in cardiac output, pulmonary arterial pressure, and systemic vascular resistance. H2S infusion studies show that decreases in systemic arterial pressure, heart rate, cardiac output, and systemic vascular resistance are well-maintained, and responses to Na2S are reversible. Decreases in heart rate were not blocked by atropine, suggesting that the bradycardia was independent of parasympathetic activation and was mediated by an effect on the sinus node. The decreases in systemic arterial pressure were not attenuated by hexamethonium, glybenclamide, Nw-nitro-l-arginine methyl ester hydrochloride, sodium meclofenamate, ODQ, miconazole, 5-hydroxydecanoate, or tetraethylammonium, suggesting that ATP-sensitive potassium channels, nitric oxide, arachidonic acid metabolites, cyclic GMP, p450 epoxygenase metabolites, or large conductance calcium-activated potassium channels are not involved in mediating hypotensive responses to the H2S donors in the rat and that responses are not centrally mediated. The present data indicate that decreases in systemic arterial pressure in response to the H2S donors can be mediated by decreases in vascular resistance and cardiac output and that the donors have an effect on the sinus node independent of the parasympathetic system. The present data indicate that the mechanism of the peripherally mediated hypotensive response to the H2S donors is uncertain in the intact rat. PMID:26071540

  18. Extended Producer Responsibility and Product Stewardship for Tobacco Product Waste

    PubMed Central

    Curtis, Clifton; Collins, Susan; Cunningham, Shea; Stigler, Paula; Novotny, Thomas E

    2015-01-01

    This paper reviews several environmental principles, including Extended Producer Responsibility (EPR), Product Stewardship (PS), the Polluter Pays Principle (PPP), and the Precautionary Principle, as they may apply to tobacco product waste (TPW). The review addresses specific criteria that apply in deciding whether a particular toxic product should adhere to these principles; presents three case studies of similar approaches to other toxic and/or environmentally harmful products; and describes 10 possible interventions or policy actions that may help prevent, reduce, and mitigate the effects of TPW. EPR promotes total lifecycle environmental improvements, placing economic, physical, and informational responsibilities onto the tobacco industry, while PS complements EPR, but with responsibility shared by all parties involved in the tobacco product lifecycle. Both principles focus on toxic source reduction, post-consumer take-back, and final disposal of consumer products. These principles when applied to TPW have the potential to substantially decrease the environmental and public health harms of cigarette butts and other TPW throughout the world. TPW is the most commonly littered item picked up during environmental, urban, and coastal cleanups globally. PMID:26457262

  19. Evaluation of Anxiety Induced Cardiovascular Response in known Hypertensive Patients Undergoing Exodontia - A Prospective Study

    PubMed Central

    Rayapati, Dilip Kumar; Puttiah, Raghuveer Hosahalli; Tavane, Prashanth; Singh, Shobha Eswara; Rangan, Vinod; Kalakunta, Prithvi Raj

    2016-01-01

    Introduction Anxiety towards exodontic procedures is a common occurrence in dental practice. In hypertensive patients this anxiety induced stress may have an effect on cardiovascular system which may be clinically significant. Aim To evaluate the cardiovascular changes in hypertensive patients that may manifest following anxiety induced stress in patients undergoing exodontic procedures under local anaesthesia. Materials and Methods Eighty known hypertensive patients under medication reporting to Department of Oral and Maxillofacial surgery, Dayananda Sagar College of Dental Sciences Bangalore, Karnataka, India for extraction of teeth were taken up for the study. Anxiety was measured before local anaesthetic delivery using Amsterdam Pre-operative Anxiety and Information Scale (APAIS). Cardiovascular response data including blood pressure, heart rate, pulse rate, oxygen saturation and electrocardiographic changes were measured pre-operatively, immediately after local anaesthesia administration and Post-operatively at five, ten and fifteen minutes interval. Kruskal-Wallis test was used to compare continuous variables before and after the injection of local anaesthesia including heart rate, pulse rate, oxygen saturation, and blood pressure. Repeated-measures analysis of variance (ANOVA) was used to analyse the significance of changes in heart rate, pulse rate, blood pressure, and oxygen saturation over time between groups.Chi-square test was used to analyse the significance of electrocardiographic changes Results The results revealed that the mean anxiety score before administration of local anaesthetic was 9.91(S.D ±2.9) with a range 4-20. Severe preoperative anxiety (<12) was associated with significantly increased heart rate, pulse rate, systolic blood pressure. At the pre-injection phase the mean values were systolic blood pressure (130.72±9.2), diastolic blood pressure (81.6±7.7), heart rate (72.7±11.9) and oxygen saturation (95.2±1.9). These values were

  20. Bupropion response on sleep quality in patients with depression: implications for increased cardiovascular disease risk.

    PubMed

    Schramm, Preetam J; Poland, Russell E; Rao, Uma

    2014-02-01

    Depression could be an independent risk factor for cardiovascular disease. We assessed bupropion response in depressed patients by polysomnography (PSG) and cardiopulmonary coupling (CPC) variables. Nineteen subjects participated in a two-session, two consecutive night PSG protocol. Participants received either placebo or bupropion-SR 150 mg, orally, in a randomized, double-blind cross-over fashion on night two. Outcome variables were: sleep stages, REM latency, stable, unstable sleep and very low frequency coupling (VLFC). CPC analysis uses heart rate variability and the electrocardiogram's R-wave amplitude fluctuations associated with respiration to generate frequency maps. Bupropion increased REM latency (p=0.043) but did not impact PSG sleep continuity, architecture and CPC variables. A trend (p=0.092) was observed towards increasing VLFC duration. Bupropion increased the number of stable-unstable sleep transitions (p=0.036). Moderate to strong correlations between PSG and CPC variables were found on placebo and bupropion nights. Limitations include a small sample size, limited power to detect CPC changes and lack of normal controls for comparison. Increased stable-unstable sleep transitions and VLFC duration may indicate vulnerability to cardiovascular disease due to their association with low heart rate variability that has been associated with increased mortality raising the question whether the beneficial effects of the antidepressant medication outweighs the impact on cardiopulmonary dynamics.

  1. Minimum anesthetic concentration and cardiovascular dose-response relationship of isoflurane in cinereous vultures (Aegypius monachus).

    PubMed

    Kim, Young K; Lee, Scott S; Suh, Euy H; Lee, Lyon; Lee, Hee C; Lee, Hyo J; Yeon, Seong C

    2011-09-01

    This study aimed to determine the minimum anesthetic concentration (MAC) and dose-related cardiovascular effects of isoflurane during controlled ventilation in cinereous vultures (Aegypius monachus). The MAC was determined for 10 cinereous vultures as the midpoint between the end-tidal isoflurane concentration that allows gross purposeful movement and that which prevents the movement in response to clamping a pedal digit. Immediately after the MAC was determined, the cardiovascular effects of isoflurane at 1.0, 1.5, and 2.0 times the MAC were investigated in seven of the 10 birds. The MAC of isoflurane for 10 cinereous vultures during controlled ventilation was 1.06 +/- 0.07% (mean +/- SD). When the isoflurane concentration was increased to 1.5 and 2.0 times the MAC, there was significant dose-dependent decrease in the arterial blood pressure. However, the heart rate did not change over a range of 1.0 to 2.0 times the MAC.

  2. Captive European starlings (Sturnus vulgaris) in breeding condition show an increased cardiovascular stress response to intruders.

    PubMed

    Dickens, Molly J; Nephew, Benjamin C; Romero, L Michael

    2006-01-01

    European starlings (Sturnus vulgaris) alter their physiology and behavior between seasons, becoming territorial during the spring/summer and flocking during the fall/winter. We used captive male starlings in breeding (photostimulated to 18L : 6D) and nonbreeding (11L : 13D) conditions to determine whether changing physiology and behavior alters their reaction to crowding. One or five intruders entered a resident's cage without human disturbance. A subcutaneous heart rate transmitter recorded cardiovascular output in residents. Corticosterone and testosterone were measured in plasma samples taken before and after the intrusion. While corticosterone concentrations did not change, heart rate changed significantly, indicating that these responses can be regulated independently. Long-day birds showed a significantly elevated heart rate response to the single-bird intrusion compared to short-day birds. Whereas five intruders elicited an identical peak response in both groups, long-day birds also demonstrated an equivalent response to one intruder. In addition, one intruder induced longer elevation in heart rate for long-day birds. Male starlings in breeding condition, therefore, demonstrate an increased sensitivity to additional conspecifics. This seasonal shift in response suggests that a higher tolerance for intrusion (i.e., considering a nearby starling as less stressful) may facilitate flocking behavior, while a lower tolerance may aid in territoriality. PMID:16927240

  3. Cardiovascular and behavioral effects produced by administration of liposome-entrapped GABA into the rat central nervous system.

    PubMed

    Vaz, G C; Bahia, A P C O; de Figueiredo Müller-Ribeiro, F C; Xavier, C H; Patel, K P; Santos, R A S; Moreira, F A; Frézard, F; Fontes, M A P

    2015-01-29

    Liposomes are nanosystems that allow a sustained release of entrapped substances. Gamma-aminobutyric acid (GABA) is the most prevalent inhibitory neurotransmitter of the central nervous system (CNS). We developed a liposomal formulation of GABA for application in long-term CNS functional studies. Two days after liposome-entrapped GABA was injected intracerebroventricularly (ICV), Wistar rats were submitted to the following evaluations: (1) changes in mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA) to ICV injection of bicuculline methiodide (BMI) in anesthetized rats; (2) changes in cardiovascular reactivity to air jet stress in conscious rats; and (3) anxiety-like behavior in conscious rats. GABA and saline-containing pegylated liposomes were prepared with a mean diameter of 200 nm. Rats with implanted cannulas targeted to lateral cerebral ventricle (n = 5-8/group) received either GABA solution (GS), empty liposomes (EL) or GABA-containing liposomes (GL). Following (48 h) central microinjection (2 μL, 0.09 M and 99 g/L) of liposomes, animals were submitted to the different protocols. Animals that received GL demonstrated attenuated response of RSNA to BMI microinjection (GS 48 ± 9, EL 43 ± 9, GL 11 ± 8%; P < 0.05), blunted tachycardia in the stress trial (ΔHR: GS 115 ± 14, EL 117 ± 10, GL 74 ± 9 bpm; P<0.05) and spent more time in the open arms of elevated plus maze (EL 6 ± 2 vs. GL 18 ± 5%; P = 0.028) compared with GS and EL groups. These results indicate that liposome-entrapped GABA can be a potential tool for exploring the chronic effects of GABA in specific regions and pathways of the central nervous system.

  4. Pulmonary and cardiovascular responses of rats to inhalation of a commercial antimicrobial spray containing titanium dioxide nanoparticles

    PubMed Central

    McKinney, W.; Jackson, M.; Sager, T.M.; Reynolds, J.S.; Chen, B.T.; Afshari, A.; Krajnak, K.; Waugh, S.; Johnson, C.; Mercer, R.R.; Frazer, D.G.; Thomas, T.A.; Castranova, V.

    2015-01-01

    Our laboratory has previously demonstrated that application of an antimicrobial spray product containing titanium dioxide (TiO2) generates an aerosol of titanium dioxide in the breathing zone of the applicator. The present report describes the design of an automated spray system and the characterization of the aerosol delivered to a whole body inhalation chamber. This system produced stable airborne levels of TiO2 particles with a median count size diameter of 110 nm. Rats were exposed to 314 mg/m3 min (low dose), 826 mg/m3 min (medium dose), and 3638 mg/m3 min (high dose) of TiO2 under the following conditions: 2.62 mg/m3 for 2 h, 1.72 mg/m3 4 h/day for 2 days, and 3.79 mg/m3 4 h/day for 4 days, respectively. Pulmonary (breathing rate, specific airway resistance, inflammation, and lung damage) and cardiovascular (the responsiveness of the tail artery to constrictor or dilatory agents) endpoints were monitored 24 h post-exposure. No significant pulmonary or cardiovascular changes were noted at low and middle dose levels. However, the high dose caused significant increases in breathing rate, pulmonary inflammation, and lung cell injury. Results suggest that occasional consumer use of this antimicrobial spray product should not be a hazard. However, extended exposure of workers routinely applying this product to surfaces should be avoided. During application, care should be taken to minimize exposure by working under well ventilated conditions and by employing respiratory protection as needed. It would be prudent to avoid exposure to children or those with pre-existing respiratory disease. PMID:22642294

  5. WISE-2005: Integrative Cardiovascular Responses with LBNP during 60-Day Bed Rest in Women

    NASA Technical Reports Server (NTRS)

    Hughson, R. L.; Kerbeci, P.; Arbeille, Ph.; Mattar, L.; Shoemaker, J. K.

    2005-01-01

    During 2005, 24 women will take part in the Women International Space-simulation for Exploration (WISE). In this paper we report on the first phase that studied 4 Exercise (EX+LBNP), 4 nutrition (NUT), and 4 no countermeasure control (CON) subjects. The EX+LBNP group completed regular exercise on a treadmill inside LBNP, flywheel resistive exercise and static periods of LBNP, and had recovery days. The NUT group received daily protein supplements. Integrative cardiovascular responses were obtained and here we report data for heart rate during LBNP, blood volume and angiotensin 11. LBNP was applied at 0, -10, -20 and -30 mmHg for 2-minutes for each stage. Blood was sampled prebed rest and on HDT-60. After 60-days head down bed rest, HR in the CON group increased by 6.1+/-2.8 bpm at rest and by 20.7+/-5.0 bpm at -30 mmHg LBNP. The EX+LBNP group had increases of 3.6+/-5.6 and 11.6+/-5.4 bpm, while the NUT group HR increased 2.6+/-3.1 and 9.4+/-3.6 bpm. The EX+LBNP group had almost no change in blood volume or plasma angiotensin II from pre-bed rest to HDT60, while both the CON and NUT groups had larger increases in plasma volume and almost double concentrations of angiotensin II. These data show a positive effect in the EX+LBNP group on the heart rate response as well as an unexpected possible benefit in the NUT group. Further studies are required to confirm possible cardiovascular benefits of the protein supplement.

  6. Particle-induced pulmonary acute phase response may be the causal link between particle inhalation and cardiovascular disease

    PubMed Central

    Saber, Anne T; Jacobsen, Nicklas R; Jackson, Petra; Poulsen, Sarah Søs; Kyjovska, Zdenka O; Halappanavar, Sabina; Yauk, Carole L; Wallin, Håkan; Vogel, Ulla

    2014-01-01

    Inhalation of ambient and workplace particulate air pollution is associated with increased risk of cardiovascular disease. One proposed mechanism for this association is that pulmonary inflammation induces a hepatic acute phase response, which increases risk of cardiovascular disease. Induction of the acute phase response is intimately linked to risk of cardiovascular disease as shown in both epidemiological and animal studies. Indeed, blood levels of acute phase proteins, such as C-reactive protein and serum amyloid A, are independent predictors of risk of cardiovascular disease in prospective epidemiological studies. In this review, we present and review emerging evidence that inhalation of particles (e.g., air diesel exhaust particles and nanoparticles) induces a pulmonary acute phase response, and propose that this induction constitutes the causal link between particle inhalation and risk of cardiovascular disease. Increased levels of acute phase mRNA and proteins in lung tissues, bronchoalveolar lavage fluid and plasma clearly indicate pulmonary acute phase response following pulmonary deposition of different kinds of particles including diesel exhaust particles, nanoparticles, and carbon nanotubes. The pulmonary acute phase response is dose-dependent and long lasting. Conversely, the hepatic acute phase response is reduced relative to lung or entirely absent. We also provide evidence that pulmonary inflammation, as measured by neutrophil influx, is a predictor of the acute phase response and that the total surface area of deposited particles correlates with the pulmonary acute phase response. We discuss the implications of these findings in relation to occupational exposure to nanoparticles. How to cite this article: WIREs Nanomed Nanobiotechnol 2014, 6:517–531. doi: 10.1002/wnan.1279 PMID:24920450

  7. The cardiovascular and endocrine responses to voluntary and forced diving in trained and untrained rats

    PubMed Central

    DiNovo, Karyn. M.; Connolly, Tiffanny M.

    2010-01-01

    The mammalian diving response, consisting of apnea, bradycardia, and increased total peripheral resistance, can be modified by conscious awareness, fear, and anticipation. We wondered whether swim and dive training in rats would 1) affect the magnitude of the cardiovascular responses during voluntary and forced diving, and 2) whether this training would reduce or eliminate any stress due to diving. Results indicate Sprague-Dawley rats have a substantial diving response. Immediately upon submersion, heart rate (HR) decreased by 78%, from 453 ± 12 to 101 ± 8 beats per minute (bpm), and mean arterial pressure (MAP) decreased 25%, from 143 ± 1 to 107 ± 5 mmHg. Approximately 4.5 s after submergence, MAP had increased to a maximum 174 ± 3 mmHg. Blood corticosterone levels indicate trained rats find diving no more stressful than being held by a human, while untrained rats find swimming and diving very stressful. Forced diving is stressful to both trained and untrained rats. The magnitude of bradycardia was similar during both voluntary and forced diving, while the increase in MAP was greater during forced diving. The diving response of laboratory rats, therefore, appears to be dissimilar from that of other animals, as most birds and mammals show intensification of diving bradycardia during forced diving compared with voluntary diving. Rats may exhibit an accentuated antagonism between the parasympathetic and sympathetic branches of the autonomic nervous system, such that in the autonomic control of HR, parasympathetic activity overpowers sympathetic activity. Additionally, laboratory rats may lack the ability to modify the degree of parasympathetic outflow to the heart during an intense cardiorespiratory response (i.e., the diving response). PMID:19923359

  8. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress.

    PubMed

    Wawrzyniak, Andrew J; Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-05-01

    Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. PMID:26894967

  9. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress

    PubMed Central

    Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-01-01

    Abstract Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75‐min recovery. RT measures were generated from an ex‐Gaussian distribution that yielded three predictors: mu‐RT, sigma‐RT, and tau‐RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = −.009, SE = .005, p = .09) and diastolic (B = −.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = −.007, SE = .003, p = .03) and impaired vagal tone (B = −.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. PMID:26894967

  10. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress.

    PubMed

    Wawrzyniak, Andrew J; Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-05-01

    Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses.

  11. Physiologic Responses Produced by Active and Passive Personal Cooling Vests

    NASA Technical Reports Server (NTRS)

    Ku, Yu-Tsuan E.; Lee, Hank C.; Montgomery, Leslie D.; Luna, Bernadette

    2000-01-01

    Personal thermoregulatory systems which provide chest cooling are used in the industrial and aerospace environments to alleviate thermal stress. However, little information is available regarding the physiologic and circulatory changes produced by routine operation of these systems. The objectives of this study were to document and compare the subjects' response to three cooling vests in their recommended configurations. The Life Enhancement Tech (LET) lightweight active cooling vest with cap, the MicroClimate Systems Change of Phase garment (MCS), and the Steele Vest were each used to cool the chest regions of 12 male and 8 female Healthy subjects (21 to 69 yr.) in this study. The subjects, seated in an upright position at normal room temperature (approx. 22 C), were tested for 60 min. with one of the cooling garments. The LET active garment had an initial coolant fluid inlet temperature of 60 F, and was ramped down to 50 F. Oral, right and left ear canal temperatures were logged manually every 5 min. Arm, leg, chest and rectal temperatures; heart rate; and respiration were recorded continuously on a U.F.I., Inc. Biolog ambulatory monitor. For men, all three vests had similar, significant cooling effects. Decreases in the average rectal temperature, oral temperature, and ear canal temperatures were approximately 0.2 C, 0.2 C and 0.1 C, respectively. In contrast to the men, the female subjects wearing the MCS and Steel vests had similar cooling responses in which the core temperature remained elevated and oral and ear canal temperatures did not drop. The LET active garment cooled most of the female subjects in this study; rectal, oral and ear temperature decreased about 0.2 C, 0.3 C and 0.3 C, respectively. These results show that the garment configurations tested do not elicit a similar thermal response in all subjects. A gender difference is evident. The LET active garment configuration was most effective in decreasing temperatures of the female subjects; the MCS

  12. Predicting in vivo cardiovascular properties of β-blockers from cellular assays: a quantitative comparison of cellular and cardiovascular pharmacological responses

    PubMed Central

    Baker, Jillian G.; Kemp, Philip; March, Julie; Fretwell, Laurice; Hill, Stephen J.; Gardiner, Sheila M.

    2011-01-01

    β-Adrenoceptor antagonists differ in their degree of partial agonism. In vitro assays have provided information on ligand affinity, selectivity, and intrinsic efficacy. However, the extent to which these properties are manifest in vivo is less clear. Conscious freely moving rats, instrumented for measurement of heart rate (β1; HR) and hindquarters vascular conductance (β2; HVC) were used to measure receptor selectivity and ligand efficacy in vivo. CGP 20712A caused a dose-dependent decrease in basal HR (P<0.05, ANOVA) at 5 doses between 6.7 and 670 μg/kg (i.v.) and shifted the dose-response curve for isoprenaline to higher agonist concentrations without altering HVC responses. In contrast, at doses of 67 μg/kg (i.v.) and above, ICI 118551 substantially reduced the HVC response to isoprenaline without affecting HR responses. ZD 7114, xamoterol, and bucindolol significantly increased basal HR (ΔHR: +122±12, +129±11, and +59±11 beats/min, respectively; n=6), whereas other β-blockers caused significant reductions (all at 2 mg/kg i.v.). The agonist effects of xamoterol and ZD 7114 were equivalent to that of the highest dose of isoprenaline. Bucindolol, however, significantly antagonized the response to the highest doses isoprenaline. An excellent correlation was obtained between in vivo and in vitro measures of β1-adrenoceptor efficacy (R2=0.93; P<0.0001).—Baker, J. G., Kemp, P., March, J., Fretwell, L., Hill, S. J., Gardiner, S. M. Predicting in vivo cardiovascular properties of β-blockers from cellular assays: a quantitative comparison of cellular and cardiovascular pharmacological responses. PMID:21865315

  13. The effects of fasting on the thermogenic, metabolic and cardiovascular responses to infused adrenaline.

    PubMed

    Webber, J; Taylor, J; Greathead, H; Dawson, J; Buttery, P J; Macdonald, I A

    1995-10-01

    The effects of fasting on the thermogenic, lipolytic and cardiovascular responses to adrenaline were examined in nine normal, young, non-obese subjects. Each subject attended for study after 12, 36 and 72 h fasting. After basal measurements adrenaline was infused at 25 ng/min per kg ideal body weight for 90 min. Fasting increased the thermogenic effect of the adrenaline (mean 14.6 (SE 1.7), 16.6 (SE 1.8), 22.6 (SE 1.6) J/min per kg fat-free mass after 12, 36 and 72 h fasting respectively; P < 0.001, ANOVA). Basal plasma palmitate turnover increased with duration of fasting (1.48 (SE 0.22), 1.95 (SE 0.34) and 2.26 (SE 0.33) mumol/min per kg body weight; P < 0.001, ANOVA), but the response to adrenaline was unaffected by fasting. The percentage values for basal plasma palmitate turnover oxidized were 44 (SE 2; 12 h), 46 (SE 5; 36 h) and 42 (SE 4)% (72 h). In response to adrenaline this percentage fell, suggesting that adrenaline infusion may favour intra-tissue lipid oxidation.

  14. Effects of short-term and prolonged immersion on the cardiovascular responses to exercise.

    PubMed

    Kame, V D; Pendergast, D R

    1995-01-01

    The primary purpose of this investigation was to examine the effects of water immersion in 35 degrees C water, per se, and the effects of 3 h of water immersion on the physiological responses to exercise. Experiments in air were conducted after 15 min of water immersion and after 3 h of water immersion. After each condition, exercises of 20%, 40%, 60%, 80%, and 100% of the subject's maximum oxygen consumption were performed on a cycle ergometer. Oxygen consumption (VO2), cardiac output, heart rate (HR), stroke volume, and blood pressure were determined. At submaximal workloads, no significant differences in the data were observed. The VO2 at the maximal workload after 3 h of immersion (3.32 +/- 0.15 L.min-1) was significantly higher than the value after 15 min of immersion (3.03 +/- 0.20 L.min-1). Both of these values were significantly lower than the value in air (3.83 +/- 0.30 L.min-1). The peak HR's were significantly higher after 3 h of immersion (167 +/- 2 b.min-1). These observations suggest that 3 h of immersion can cause alterations in the cardiovascular responses to maximal exercise; however, submaximal responses were unaffected.

  15. The assessment of Big Five Personality Factors and Temperament Domains as modifiers of cardiovascular response to occupational stress.

    PubMed

    Merecz, D; Makowska, Z; Makowiec-Dabrowska, T

    1999-01-01

    The aim of the study was to explore the role of Big Five Personality Factors and Temperament Domains as the factors influencing cardiovascular response to work, and their moderating effect on the relationship between occupational stress and cardiovascular reactivity. The self-reported data on occupational stress and filled in NEO-Five Factor Inventory by Costa, and McCrae and Pavlovian Temperament Survey by Strelau et al. were collected from 97 bank clerks employed in large bank branches. The subjects also responded to the questionnaire on personal and professional background factors. A 24 hour monitoring of cardiovascular reactivity (heart rate and blood pressure) was also provided. Conscientiousness was found to be the only modifier of cardiovascular response to occupational stress reflected by systolic blood pressure. Several main, independent of stress effects of personality and temperament domains were also found. The ratio of heart rate at work to heart rate during sleep was associated with the strength of excitatory process, the percentage of maximum heart rate index with Conscientiousness, and systolic blood pressure at work was influenced by the strength of inhibitory process. However, generally speaking, physiological indicators of the cardiovascular system functioning were not very sensitive to changes in values of personality and temperament variables at the level of occupational stress reported by the bank clerks who participated in the study.

  16. Sidestream cigarette smoke effects on cardiovascular responses in conscious rats: involvement of oxidative stress in the fourth cerebral ventricle

    PubMed Central

    2012-01-01

    Background Cigarette exposure increases brain oxidative stress. The literature showed that increased brain oxidative stress affects cardiovascular regulation. However, no previous study investigated the involvement of brain oxidative stress in animals exposed to cigarette and its relationship with cardiovascular regulation. We aimed to evaluate the effects of central catalase inhibition on baroreflex and cardiovascular responses in rats exposed to sidestream cigarette smoke (SSCS). Methods We evaluated males Wistar rats (320-370 g), which were implanted with a stainless steel guide cannula into the fourth cerebral ventricle (4th V). Femoral artery and vein were cannulated for mean arterial pressure (MAP) and heart rate (HR) measurement and drug infusion, respectively. Rats were exposed to SSCS during three weeks, 180 minutes, 5 days/week (CO: 100-300 ppm). Baroreflex was tested with a pressor dose of phenylephrine (PHE, 8 μg/kg, bolus) to induce bradycardic reflex and a depressor dose of sodium nitroprusside (SNP, 50 μg/kg, bolus) to induce tachycardic reflex. Cardiovascular responses were evaluated before, 5, 15, 30 and 60 minutes after 3-amino-1,2,4-triazole (ATZ, catalase inhibitor, 0.001 g/100 μL) injection into the 4th V. Results Central catalase inhibition increased basal HR in the control group during the first 5 minutes. SSCS exposure increased basal HR and attenuated bradycardic peak during the first 15 minutes. Conclusion We suggest that SSCS exposure affects cardiovascular regulation through its influence on catalase activity. PMID:22463380

  17. The Genetic Response to Short-term Interventions Affecting Cardiovascular Function: Rationale and Design of the HAPI Heart Study

    PubMed Central

    Mitchell, Braxton D.; McArdle, Patrick F.; Shen, Haiqing; Rampersaud, Evadnie; Pollin, Toni I.; Bielak, Lawrence F.; Jaquish, Cashell; Douglas, Julie A.; Roy-Gagnon, Marie-Hélène; Sack, Paul; Naglieri, Rosalie; Hines, Scott; Horenstein, Richard B.; Chang, Yen-Pei C.; Post, Wendy; Ryan, Kathleen A.; Brereton, Nga Hong; Pakyz, Ruth E.; Sorkin, John; Damcott, Coleen M.; O’Connell, Jeffrey R.; Mangano, Charles; Corretti, Mary; Vogel, Robert; Herzog, William; Weir, Matthew R.; Peyser, Patricia A.; Shuldiner, Alan R.

    2008-01-01

    Background The etiology of cardiovascular disease (CVD) is multifactorial. Efforts to identify genes influencing CVD risk have met with limited success to date, likely due to the small effect sizes of common CVD risk alleles and the presence of gene by gene and gene by environment interactions. Methods The Heredity and Phenotype Intervention (HAPI) Heart Study was initiated in 2002 to measure the cardiovascular response to four short-term interventions affecting cardiovascular risk factors and to identify the genetic and environmental determinants of these responses. The measurements included blood pressure responses to the cold pressor stress test and to a high salt diet, triglyceride excursion in response to a high fat challenge, and response in platelet aggregation to aspirin therapy. Results The interventions were carried out in 868 relatively healthy Amish adults from large families. The heritabilities of selected response traits for each intervention ranged from 8–38%, suggesting that some of the variation associated with response to each intervention can be attributed to the additive effects of genes. Conclusions Identifying these response genes may identify new mechanisms influencing CVD and may lead to individualized preventive strategies and improved early detection of high-risk individuals. PMID:18440328

  18. Mindfulness may both moderate and mediate the effect of physical fitness on cardiovascular responses to stress: a speculative hypothesis

    PubMed Central

    Demarzo, Marcelo M. P.; Montero-Marin, Jesús; Stein, Phyllis K.; Cebolla, Ausiàs; Provinciale, Jaime G.; García-Campayo, Javier

    2014-01-01

    The psychological construct of mindfulness refers to an awareness that emerges by intentionally paying attention to the present experience in a non-judgmental or evaluative way. This particular quality of awareness has been associated to several indicators of physical and psychological health, and can be developed using mindfulness-based interventions (MBIs), and therefore MBIs have been successfully applied as preventive and complementary interventions and therapies in medicine and psychology. Together with quiet sitting and lying meditation practices, mindful physical exercises such as “mindful walking” and “mindful movement” are key elements in MBIs and couple muscular activity with an internally directed focus, improving interoceptive attention to bodily sensations. In addition, MBIs seem to share similar mechanisms with physical fitness (PF) by which they may influence cardiovascular responses to stress. Based on these facts, it is feasible to raise the question of whether physical training itself may induce the development of that particular quality of awareness associated with mindfulness, or if one's dispositional mindfulness (DM) (the tendency to be more mindful in daily life) could moderate the effects of exercise on cardiovascular response to stress. The role of mindfulness as a mediator or moderator of the effect of exercise training on cardiovascular responses to stress has barely been studied. In this study, we have hypothesized pathways (moderation and mediation) by which mindfulness could significantly influence the effects of PF on cardiovascular responses to stress and discussed potential practical ways to test these hypotheses. PMID:24723891

  19. Susceptibility of the aging Brown Norway rat to carbaryl, an anti-cholinesterase-based insecticide: Thermoregulatory and cardiovascular responses.

    EPA Science Inventory

    The proportion of aged in the United States is projected to expand markedly for the next several decades. Hence, the U.S.EPA is assessing if the aged are more susceptible to environmental toxicants. The thermoregulatory and cardiovascular responses of young adult, mature adult, a...

  20. Mindfulness may both moderate and mediate the effect of physical fitness on cardiovascular responses to stress: a speculative hypothesis.

    PubMed

    Demarzo, Marcelo M P; Montero-Marin, Jesús; Stein, Phyllis K; Cebolla, Ausiàs; Provinciale, Jaime G; García-Campayo, Javier

    2014-01-01

    The psychological construct of mindfulness refers to an awareness that emerges by intentionally paying attention to the present experience in a non-judgmental or evaluative way. This particular quality of awareness has been associated to several indicators of physical and psychological health, and can be developed using mindfulness-based interventions (MBIs), and therefore MBIs have been successfully applied as preventive and complementary interventions and therapies in medicine and psychology. Together with quiet sitting and lying meditation practices, mindful physical exercises such as "mindful walking" and "mindful movement" are key elements in MBIs and couple muscular activity with an internally directed focus, improving interoceptive attention to bodily sensations. In addition, MBIs seem to share similar mechanisms with physical fitness (PF) by which they may influence cardiovascular responses to stress. Based on these facts, it is feasible to raise the question of whether physical training itself may induce the development of that particular quality of awareness associated with mindfulness, or if one's dispositional mindfulness (DM) (the tendency to be more mindful in daily life) could moderate the effects of exercise on cardiovascular response to stress. The role of mindfulness as a mediator or moderator of the effect of exercise training on cardiovascular responses to stress has barely been studied. In this study, we have hypothesized pathways (moderation and mediation) by which mindfulness could significantly influence the effects of PF on cardiovascular responses to stress and discussed potential practical ways to test these hypotheses. PMID:24723891

  1. Cardiovascular responses in humans to experimental chewing of gums of different consistencies.

    PubMed

    Farella, M; Bakke, M; Michelotti, A; Marotta, G; Martina, R

    1999-10-01

    Although the cardiovascular effects of exercise have been extensively investigated in man, little attention has been paid to such responses to jaw muscle activity. The aim here was to investigate the general cardiovascular effects of chewing activity in a single-blind, cross-over design. Ten healthy individuals performed one of the following chewing tasks in four separate sessions: chewing a very hard gum, chewing a moderately hard gum, chewing a soft gum, and "empty chewing" without a bolus. Unilateral chewing of gum or empty chewing was performed for 20 min on the participant's most convenient chewing side at a constant rate of 80 cycles/min. In each session, heart rate and arterial blood pressure were recorded together with electromyographic activity in the masseter and anterior temporalis muscles on the chewing side. Ratings of perceived masticatory fatigue were recorded with visual analogue scales. The heart rate and blood pressure were significantly increased (ANOVA; p < or= 0.01) during the chewing tasks and the increases were, in parallel with the muscle activity, more pronounced the harder the gum. With the very hard gum, heart rate increased by up to 11 beats/min, the systolic blood pressure was 14 mmHg (1.9kPa) higher, and the diastolic blood pressure was 11 mmHg (1.5kPa) higher. The perceived fatigue was proportional to the level of muscle activity. After 10 min of recovery from exercise, heart rate and arterial blood pressures were slightly but still significantly elevated. The results demonstrate that chewing is associated with general circulatory effects proportional to the bolus resistance.

  2. Cardiovascular regulation in humans in response to oscillatory lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Levenhagen, D. K.; Evans, J. M.; Wang, M.; Knapp, C. F.

    1994-01-01

    The frequency response characteristics of human cardiovascular regulation during hypotensive stress have not been determined. We therefore exposed 10 male volunteers to seven frequencies (0.004-0.1 Hz) of oscillatory lower body negative pressure (OLBNP; 0-50 mmHg). Fourier spectra of arterial pressure (AP), central venous pressure (CVP), stroke volume (SV), cardiac output (CO), heart rate (HR), and total peripheral resistance (TPR) were determined and first harmonic mean, amplitude, and phase angles with respect to OLBNP are presented. AP was relatively well regulated as demonstrated by small oscillations in half amplitude (3.5 mmHg) that were independent of OLBNP frequency and similar to unstressed control spectra. Due to the biomechanics of the system, the magnitudes of oscillations in calf circumference (CC) and CVP decreased with increasing frequency; therefore, we normalized responses by these indexes of the fluid volume shifted. The ratios of oscillations in AP to oscillations in CC increased by an order of magnitude, whereas oscillations in CVP to oscillations in CC and oscillations in AP to oscillations in CVP both tripled between 0.004 and 0.1 Hz. Therefore, even though the amount of fluid shifted by OLBNP decreased with increasing frequency, the magnitude of both CVP and AP oscillations per volume of fluid shifted increased (peaking at 0.08 Hz). The phase relationships between variables, particularly the increasing lags in SV and TPR, but not CVP, indicated that efferent responses with lags of 5-6 s could account for the observed responses. We conclude that, at frequencies below 0.02 Hz, the neural system of humans functioned optimally in regulating AP; OLBNP-induced decreases in SV (by as much as 50%) were counteracted by appropriate oscillations in HR and TPR responses. As OLBNP frequency increased, SV, TPR, and HR oscillations increasingly lagged the input and became less optimally timed for AP regulation.

  3. Policy trends of extended producer responsibility in Malaysia.

    PubMed

    Agamuthu, P; Victor, Dennis

    2011-09-01

    This paper seeks to examine the provisions for extended producer responsibility (EPR) within the Malaysian environmental and waste management policies and to determine its existing practice and future prospects in Malaysia. Malaysian waste generation has been increasing drastically where solid waste generation was estimated to increase from about 9.0 million tonnes in 2000 to about 10.9 million tonnes in 2010, to about 12.8 million tonnes in 2015 and finally to about 15.6 million tonnes in 2020. Malaysian e-waste was estimated to be about 652 909 tonnes in 2006 and was estimated to increase to about 706 000 tonnes in 2010 and finally to about 1.2 million tonnes in 2020. The projected increasing generation of both solid waste and scheduled wastes is expected to burden the country's resources and environment in managing these wastes in a sustainable manner. The concept of EPR is provided for in the Malaysia waste management system via the Environmental Quality Act 1974 and the Solid Waste and Public Cleansing Management Act 2007. However, these provisions in the policy are generic in nature without relevant regulations to enable its enforcement and as such the concept of EPR still remains on paper whereas the existing practice of EPR in Malaysia is limited through voluntary participation. In conclusion, policy trends of EPR in Malaysia seem to indicate that Malaysia may be embarking on the path towards EPR through the enactment of an EPR regulation.

  4. Effective Bolus Dose of Sufentanil to Attenuate Cardiovascular Responses in Laryngoscopic Double-Lumen Endobronchial Intubation

    PubMed Central

    Choi, Byung-Hee; Lee, Yong-Cheol

    2016-01-01

    Background Sufentanil is a potent opioid analgesic frequently used in clinical anesthesia. Double-lumen endobronchial intubation induces profound cardiovascular responses in comparison with ordinary endotracheal intubation because of the larger tube diameter and direct irritation of the carina. Objectives The purpose of this study was to determine the effective bolus dose of sufentanil to attenuate hemodynamic changes in response to laryngoscopic double-lumen endobronchial intubation. Patients and Methods We randomly assigned 72 patients aged 18 - 65 years and with an American Society of Anesthesiologists physical status of 1 or 2 to one of four sufentanil dose groups: NS, S0.1, S0.2, or S0.3. The respective doses for the groups were as follows: normal saline, 0.1 mcg/kg of sufentanil, 0.2 mcg/kg of sufentanil, and 0.3 mcg/kg of sufentanil. Blood pressure and heart rate were recorded during the pre-anesthesia period at baseline, pre-intubation, immediate post-intubation, and every minute during 5 minutes after intubation. Results Baseline mean arterial pressures in the NS, S0.1, S0.2, and S0.3 groups were 89.8 ± 12.1, 89.2 ± 10.9, 88.8 ± 13.6, and 90.7 ± 11.1, respectively. At immediate post-intubation, the mean arterial pressures in the NS, S0.1, S0.2, and S0.3 groups were 129.7 ± 14.7, 120.7 ± 14.2, 120.8 ± 17.2, and 96.7 ± 10.4, respectively. At immediate post-intubation, the mean arterial pressure in the NS, S0.1, and S0.2 groups significantly increased from baseline (P < 0.001), but the S0.3 group showed no difference. In the time point comparison at immediate post- intubation, the S0.3 group had a significantly lower mean arterial pressure than did the NS, S0.1, and S0.2 groups (P < 0.001). Conclusions We found that 0.3 mcg/kg of sufentanil attenuates cardiovascular responses to double-lumen endobronchial intubation without adverse effects. PMID:27252903

  5. Cerebro- and Cardio-vascular Responses to Energy Drink in Young Adults: Is there a Gender Effect?

    PubMed Central

    Monnard, Cathríona R.; Montani, Jean-Pierre; Grasser, Erik K.

    2016-01-01

    Background and Purpose: Energy drinks (EDs) are suspected to induce potential adverse cardiovascular effects and have recently been shown to reduce cerebral blood flow velocity (CBFV) in young, healthy subjects. Gender differences in CBFV in response to EDs have not previously been investigated, despite the fact that women are more prone to cardiovascular disturbances such as neurocardiogenic syncope than men. Therefore, the aim of this study was to explore gender differences in cerebrovascular and cardiovascular responses to EDs. Methods: We included 45 subjects in a retrospective analysis of pooled data from two previous randomized trials carried out in our laboratory with similar protocols. Beat-to-beat blood pressure, impedance cardiography, transcranial Doppler, and end-tidal carbon dioxide (etCO2) measurements were made for at least 20 min baseline and for 80 min following the ingestion of 355 mL of a sugar-sweetened ED. Gender and time differences in cerebrovascular and cardiovascular parameters were investigated. Results: CBFV was significantly reduced in response to ED, with the greatest reduction observed in women compared with men (−12.3 ± 0.8 vs. −9.7 ± 0.8%, P < 0.05). Analysis of variance indicated significant time (P < 0.01) and gender × time (P < 0.01) effects. The percentage change in CBFV in response to ED was independent of body weight and etCO2. No significant gender difference in major cardiovascular parameters in response to ED was observed. Conclusions: ED ingestion reduced CBFV over time, with a greater reduction observed in women compared with men. Our results have potential implications for women ED consumers, as well as high-risk individuals. PMID:27559316

  6. Dietary methionine restriction in mice elicits an adaptive cardiovascular response to hyperhomocysteinemia.

    PubMed

    Ables, Gene P; Ouattara, Amadou; Hampton, Thomas G; Cooke, Diana; Perodin, Frantz; Augie, Ines; Orentreich, David S

    2015-03-06

    Dietary methionine restriction (MR) in rodents increased lifespan despite higher heart-to-body weight ratio (w/w) and hyperhomocysteinemia, which are symptoms associated with increased risk for cardiovascular disease. We investigated this paradoxical effect of MR on cardiac function using young, old, and apolipoprotein E-deficient (ApoE-KO) mice. Indeed, MR animals exhibited higher heart-to-body weight ratio (w/w) and hyperhomocysteinemia with a molecular pattern consistent with cardiac stress while maintaining the integrity of cardiac structure. Baseline cardiac function, which was measured by non-invasive electrocardiography (ECG), showed that young MR mice had prolonged QRS intervals compared with control-fed (CF) mice, whereas old and ApoE-KO mice showed similar results for both groups. Following β-adrenergic challenge, responses of MR mice were either similar or attenuated compared with CF mice. Cardiac contractility, which was measured by isolated heart retrograde perfusion, was similar in both groups of old mice. Finally, the MR diet induced secretion of cardioprotective hormones, adiponectin and fibroblast growth factor 21 (FGF21), in MR mice with concomitant alterations in cardiac metabolic molecular signatures. Our findings demonstrate that MR diet does not alter cardiac function in mice despite the presence of hyperhomocysteinemia because of the adaptive responses of increased adiponectin and FGF21 levels.

  7. A Computational Model for Thrombus Formation in Response to Cardiovascular Implantable Devices

    NASA Astrophysics Data System (ADS)

    Horn, John; Ortega, Jason; Maitland, Duncan

    2014-11-01

    Cardiovascular implantable devices elicit complex physiological responses within blood. Notably, alterations in blood flow dynamics and interactions between blood proteins and biomaterial surface chemistry may lead to the formation of thrombus. For some devices, such as stents and heart valves, this is an adverse outcome. For other devices, such as embolic aneurysm treatments, efficient blood clot formation is desired. Thus a method to study how biomedical devices induce thrombosis is paramount to device development and optimization. A multiscale, multiphysics computational model is developed to predict thrombus formation within the vasculature. The model consists of a set of convection-diffusion-reaction partial differential equations for blood protein constituents involved in the progression of the clotting cascades. This model is used to study thrombus production from endovascular devices with the goal of optimizing the device design to generate the desired clotting response. This work was performed in part under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  8. Anxious women do not show the expected decrease in cardiovascular stress responsiveness as pregnancy advances.

    PubMed

    Braeken, M A K A; Jones, A; Otte, R A; Widjaja, D; Van Huffel, S; Monsieur, G J Y J; van Oirschot, C M; Van den Bergh, B R H

    2015-10-01

    Altered stress responsiveness is a risk factor for mental and physical illness. In non-pregnant populations, it is well-known that anxiety can alter the physiological regulation of stress reactivity. Characterization of corresponding risks for pregnant women and their offspring requires greater understanding of how stress reactivity and recovery are influenced by pregnancy and women's anxiety feelings. In the current study, women were presented repeatedly with mental arithmetic stress tasks in the first and third pregnancy trimester and reported their trait anxiety using the state trait anxiety inventory. Cardiovascular stress reactivity in late pregnancy was lower than reactivity in the first pregnancy trimester (heart rate (HR): t(197)=4.98, p<.001; high frequency heart rate variability (HF HRV): t(196)=-2.09, p=.04). Less attenuation of stress reactivity occurred in more anxious women (HR: b=0.15, SE=0.06, p=.008; HF HRV: b=-10.97, SE=4.79, p=.02). The study design did not allow the influence of habituation to repeated stress task exposure to be assessed separately from the influence of pregnancy progression. Although this is a limitation, the clear differences between anxious and non-anxious pregnant women are important, regardless of the extent to which differing habituation between the groups is responsible. Less dampened stress reactivity through pregnancy may pose long-term risks for anxious women and their offspring. Follow-up studies are required to determine these risks.

  9. Dietary methionine restriction in mice elicits an adaptive cardiovascular response to hyperhomocysteinemia.

    PubMed

    Ables, Gene P; Ouattara, Amadou; Hampton, Thomas G; Cooke, Diana; Perodin, Frantz; Augie, Ines; Orentreich, David S

    2015-01-01

    Dietary methionine restriction (MR) in rodents increased lifespan despite higher heart-to-body weight ratio (w/w) and hyperhomocysteinemia, which are symptoms associated with increased risk for cardiovascular disease. We investigated this paradoxical effect of MR on cardiac function using young, old, and apolipoprotein E-deficient (ApoE-KO) mice. Indeed, MR animals exhibited higher heart-to-body weight ratio (w/w) and hyperhomocysteinemia with a molecular pattern consistent with cardiac stress while maintaining the integrity of cardiac structure. Baseline cardiac function, which was measured by non-invasive electrocardiography (ECG), showed that young MR mice had prolonged QRS intervals compared with control-fed (CF) mice, whereas old and ApoE-KO mice showed similar results for both groups. Following β-adrenergic challenge, responses of MR mice were either similar or attenuated compared with CF mice. Cardiac contractility, which was measured by isolated heart retrograde perfusion, was similar in both groups of old mice. Finally, the MR diet induced secretion of cardioprotective hormones, adiponectin and fibroblast growth factor 21 (FGF21), in MR mice with concomitant alterations in cardiac metabolic molecular signatures. Our findings demonstrate that MR diet does not alter cardiac function in mice despite the presence of hyperhomocysteinemia because of the adaptive responses of increased adiponectin and FGF21 levels. PMID:25744495

  10. Cardiovascular responses of pregnant women during aerobic exercise in water: a longitudinal study.

    PubMed

    McMurray, R G; Katz, V L; Berry, M J; Cefalo, R C

    1988-12-01

    To determine the effects of pregnancy on the cardiovascular responses to immersion and exercise in water, 12 women completed 20 min of immersion and 20 min of bicycle ergometry at 60% predicted VO2max in 30 degrees C water during their 15th, 25th, and 35th week of pregnancy as well as 8-10 weeks post partum. Immersion lowered the resting heart rate approximately 8 bts/min (P less than 0.05). Exercise in water also resulted in a lower heart rate as compared with the same level of exercise on land (132 +/- 4 vs 149 +/- 6 bts/min; P less than 0.05). Both the rest and exercise heart rate responses were independent of duration of pregnancy or pregnancy status. Post partum exercise cardiac output averaged 9.9 +/- 0.4 l/min, significantly lower (P less than 0.05) than the 15th (12.7 +/- 0.5), 25th (14.7 +/- 0.5), or 35th week (15.1 +/- 0.7 l/min). Total peripheral resistance was greatest (P less than 0.05) post partum (657 +/- 29 dyn.s/cm5) compared with either the 15th (515 +/- 27), 25th (407 +/- 18), or 35th week (450 +/- 23). The results indicate that exercise in water lowers the heart rate compared with land exercise at the same metabolic rate. The combined effect of exercise, water, and pregnancy may elevate the cardiac output more than expected on land, but the same general pattern of exercise response will be evident throughout the duration of pregnancy. The results further suggest that water alters the heart rate and blood pressure responses such that land-derived exercise target heart rates should not be used to prescribe exercise intensity in water.

  11. [Influence of the practice of meditation on the cardiovascular response in the perception and cognitive reassessment emotiogenic stimulus].

    PubMed

    Pavlov, S V; Reva, N V; Loktev, K V; Korenek, V V; Aftanas, L

    2015-03-01

    This study examines the effects of meditation on cardiovascular activity during affective image processing. 22 meditators and 20 controls were shown affective images and were asked either to attend to the images or to down-regulate negative affect (for negative images) or to up-regulate positive affect (for positive images) while continuous cardiovascular activity were recorded. During natural viewing meditators manifested identical pre-stimulus total peripheral resistance (TPR) for all images, whereas controls exhibited greatest,pre-stimulus TPR for negative images and reduced it only in the emotion regulation condition. No between-group differences were revealed for natural viewing of positive images, whereas up-regulation was associated with greater cardiac activation in meditators. The results provide a contribution to the understanding of the mechanisms responsible for the beneficial influence of meditation on cardiovascular risk factors. PMID:26016329

  12. Thermoregulatory and cardiovascular responses to creatine, glycerol and alpha lipoic acid in trained cyclists

    PubMed Central

    2012-01-01

    Background It has been shown that supplementation with creatine (Cr) and glycerol (Gly), when combined with glucose (Glu) necessary for the enhancement of Cr uptake by skeletal muscle, induces significant improvements in thermoregulatory and cardiovascular responses during exercise in the heat. Purpose To determine whether Cr/Gly-induced thermoregulatory and cardiovascular responses are maintained when the majority (~75%) of the Glu in the Cr/Gly supplement is replaced with the insulintropic agent alpha lipoic acid (Ala). Methods 22 healthy endurance trained cyclists were randomly assigned to receive either 20 g/day (4 × 5 g/day) of Cr, 2 g .kg-1 BM per day (4 × 0.5 g .kg-1 BM per day) of Gly and 150 g/day (4 × 37.5 g/day) of Glu or 20 g/day (4 × 5 g/day) of Cr monohydrate, 2 g .kg-1 BM per day (4 × 0.5 g .kg-1 BM per day) of Gly (100 g/day (4 × 25 g/day) of Glu and 1000 mg/day (4 × 250 mg/day) of Ala for 7 days for 7 days. Exercise trials were conducted pre- and post-supplementation and involved 40 min of constant-load cycling exercise at 70% O2 max by a self-paced 16.1 km time trial at 30°C and 70% relative humidity. Results Median and range values of TBW increased significantly by 2.1 (1.3-3.3) L and 1.8 (0.2-4.6) L in Cr/Gly/Glu and Cr/Gly/Glu/Ala groups respectively (P = 0.03) and of BM not significantly by 1.8 (0.2-3.0) kg and 1.2 (0.5-2.1) kg in Cr/Gly/Glu and in Cr/Gly/Glu/Ala, respectively (P = 0.75). During constant load exercise, heart rate (HR) and core temperature (Tcore) were significantly lower post-supplementation: HR was reduced on average by 3.3 ± 2.1 beats/min and by 4.8 ± 3.3 beats/min (mean ± SD) and Tcore by 0.2 ± 0.1 (mean ± SD) in the Cr/Gly/Glu and Cr/Gly/Glu/Ala, respectively The reduction in HR and Tcore was not significantly different between the supplementation groups. Conclusions In comparison to the established hyper hydrating Cr

  13. Spinal actions of substance P analogues on cardiovascular responses in the rat: a structure-activity analysis.

    PubMed

    Couture, R; Gupta, A; Kérouac, R; Escher, E; Regoli, D

    1987-03-01

    Ten substance P (SP) analogues were tested for their effects on mean arterial pressure and heart rate following intrathecal administration in the pentobarbital anaesthetized rat. The 10 analogues are [D-Pro4,D-alpha Npa7,9,10]SP(4-11) (A-I), (D-alpha Npa7,9,10]SP (A-II), [D-Trp7,9,10]SP (A-III), [D-Pro4,D-Npa7,9,Phe11]SP(4-11) (A-IV), [D-Pro4,D-beta Npa7,D-alpha Npa9,D-Phe11]SP(4-11) (A-V), [D-Pro4,Lys6,D-Trp7,9,10,Phe11]SP(4-11) (A-VI), [D-Pro4,D-Trp7,9,10,Phe11]SP(4-11) (A-VII), [D-Pro4,D-Trp7,9,10,Trp11]SP(4-11) (A-VIII), [D-Trp7,9,10,Trp11]SP (A-IX), and [D-Pro4,D-Phe7,9,10,Phe11]SP(4-11) (A-X). At 6.5 nmol, the analogues containing the amino acid D-Npa (A-I, A-II, A-IV, and A-V) or D-Phe (A-X) in positions 7, 9, or 10 of SP or its C-terminal octapeptide are devoid of the long-lasting cardio- and vaso-depressor effects, which are otherwise seen with analogues containing the amino acid D-Trp (A-III, A-VI, A-VII, A-VIII, and A-IX) in the same positions. Some of the analogues containing D-Npa maintain the initial hypotensive effect seen with SP while the analogue containing D-Phe produces only a small hypertensive response. The 10 analogues when tested at a dose that failed to alter basal mean arterial pressure and heart rate did not block the cardiovascular responses elicited by SP and no cross desensitization was observed between SP and these analogues. It appears that these SP analogues exert cardiovascular effects in the rat spinal cord probably without interacting with SP receptors.

  14. Thermoregulatory, cardiovascular, and perceptual responses to intermittent cooling during exercise in a hot, humid outdoor environment.

    PubMed

    Cleary, Michelle A; Toy, Michelle G; Lopez, Rebecca M

    2014-03-01

    Decreasing core body temperature during exercise may improve exercise tolerance, facilitate acclimatization, and prevent heat illness during summer training. We sought to evaluate the effectiveness of intermittent superficial cooling on thermoregulatory, cardiovascular, and perceptual responses during exercise in a hot humid environment. We used a randomized, counterbalanced, repeated measures investigation with 2 conditions (control and cooling) during exercise and recovery outdoors on artificial turf in a hot, humid tropical climate in the sun (wet bulb globe temperature outdoors [WBGTo], 27.0 ± 0.8° C; range, 25.8-28.1° C) and in the shade (WBGTo, 25.4 ± 0.9° C; range, 24.3-26.8° C). Participants were 10 healthy males (age, 22.6 ± 1.6 years; height, 176.0 ± 6.9 cm; mass, 76.5 ± 7.8 kg; body fat, 15.6 ± 5.4%) who wore shorts and T-shirt (control) or "phase change cooling" vest (cooling) during 5-minute rest breaks during 60 minutes of intense American football training and conditioning exercises in the heat and 30 minutes of recovery in the shade. Throughout, we measured core (Tgi) and skin (Tchest) temperature, heart rate (HR), thermal and thirst sensations, and rating of perceived exertion. We found significant (p ≤ 0.001) hypohydration (-2.1%); for Tgi, we found no significant differences between conditions (p = 0.674) during exercise and progressive decreases during recovery (p < 0.001). For [INCREMENT]Tg,i we found no significant (p = 0.090) differences. For Tchest, we found significantly (p < 0.001) decreased skin temperature in the cooling condition (Tchest, 31.85 ± 0.43° C) compared with the control condition (Tchest, 34.38 ± 0.43° C) during exercise and significantly (p < 0.001) lower skin temperature in the cooling condition (Tchest, 31.24 ± 0.47° C) compared with the control condition (Tchest, 33.48 ± 0.47° C) during recovery. For HR, we found no significant difference (p = 0.586) between the conditions during exercise; however, we

  15. Thermoregulatory, cardiovascular, and perceptual responses to intermittent cooling during exercise in a hot, humid outdoor environment.

    PubMed

    Cleary, Michelle A; Toy, Michelle G; Lopez, Rebecca M

    2014-03-01

    Decreasing core body temperature during exercise may improve exercise tolerance, facilitate acclimatization, and prevent heat illness during summer training. We sought to evaluate the effectiveness of intermittent superficial cooling on thermoregulatory, cardiovascular, and perceptual responses during exercise in a hot humid environment. We used a randomized, counterbalanced, repeated measures investigation with 2 conditions (control and cooling) during exercise and recovery outdoors on artificial turf in a hot, humid tropical climate in the sun (wet bulb globe temperature outdoors [WBGTo], 27.0 ± 0.8° C; range, 25.8-28.1° C) and in the shade (WBGTo, 25.4 ± 0.9° C; range, 24.3-26.8° C). Participants were 10 healthy males (age, 22.6 ± 1.6 years; height, 176.0 ± 6.9 cm; mass, 76.5 ± 7.8 kg; body fat, 15.6 ± 5.4%) who wore shorts and T-shirt (control) or "phase change cooling" vest (cooling) during 5-minute rest breaks during 60 minutes of intense American football training and conditioning exercises in the heat and 30 minutes of recovery in the shade. Throughout, we measured core (Tgi) and skin (Tchest) temperature, heart rate (HR), thermal and thirst sensations, and rating of perceived exertion. We found significant (p ≤ 0.001) hypohydration (-2.1%); for Tgi, we found no significant differences between conditions (p = 0.674) during exercise and progressive decreases during recovery (p < 0.001). For [INCREMENT]Tg,i we found no significant (p = 0.090) differences. For Tchest, we found significantly (p < 0.001) decreased skin temperature in the cooling condition (Tchest, 31.85 ± 0.43° C) compared with the control condition (Tchest, 34.38 ± 0.43° C) during exercise and significantly (p < 0.001) lower skin temperature in the cooling condition (Tchest, 31.24 ± 0.47° C) compared with the control condition (Tchest, 33.48 ± 0.47° C) during recovery. For HR, we found no significant difference (p = 0.586) between the conditions during exercise; however, we

  16. Particle-Induced Pulmonary Acute Phase Response Correlates with Neutrophil Influx Linking Inhaled Particles and Cardiovascular Risk

    PubMed Central

    Saber, Anne Thoustrup; Lamson, Jacob Stuart; Jacobsen, Nicklas Raun; Ravn-Haren, Gitte; Hougaard, Karin Sørig; Nyendi, Allen Njimeri; Wahlberg, Pia; Madsen, Anne Mette; Jackson, Petra; Wallin, Håkan; Vogel, Ulla

    2013-01-01

    Background Particulate air pollution is associated with cardiovascular disease. Acute phase response is causally linked to cardiovascular disease. Here, we propose that particle-induced pulmonary acute phase response provides an underlying mechanism for particle-induced cardiovascular risk. Methods We analysed the mRNA expression of Serum Amyloid A (Saa3) in lung tissue from female C57BL/6J mice exposed to different particles including nanomaterials (carbon black and titanium dioxide nanoparticles, multi- and single walled carbon nanotubes), diesel exhaust particles and airborne dust collected at a biofuel plant. Mice were exposed to single or multiple doses of particles by inhalation or intratracheal instillation and pulmonary mRNA expression of Saa3 was determined at different time points of up to 4 weeks after exposure. Also hepatic mRNA expression of Saa3, SAA3 protein levels in broncheoalveolar lavage fluid and in plasma and high density lipoprotein levels in plasma were determined in mice exposed to multiwalled carbon nanotubes. Results Pulmonary exposure to particles strongly increased Saa3 mRNA levels in lung tissue and elevated SAA3 protein levels in broncheoalveolar lavage fluid and plasma, whereas hepatic Saa3 levels were much less affected. Pulmonary Saa3 expression correlated with the number of neutrophils in BAL across different dosing regimens, doses and time points. Conclusions Pulmonary acute phase response may constitute a direct link between particle inhalation and risk of cardiovascular disease. We propose that the particle-induced pulmonary acute phase response may predict risk for cardiovascular disease. PMID:23894396

  17. Renal and cardiovascular responses to water immersion in trained runners and swimmers

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Tatro, D. L.; Rogan, R. B.

    1993-01-01

    The purpose of this study was to determine if fluid-electrolyte, renal, hormonal, and cardiovascular responses during and after multi-hour water immersion were associated with aerobic training. Additionally, we compared these responses in those who trained in a hypogravic versus a 1-g environment. Seventeen men comprised three similarly aged groups: six long-distance runners, five competitive swimmers, and six untrained control subjects. Each subject underwent 5 h of immersion in water [mean (SE)] 36.0 (0.5) degrees C to the neck. Immediately before and at each hour of immersion, blood and urine samples were collected and analyzed for sodium (Na), potassium, osmolality, and creatinine (Cr). Plasma antidiuretic hormone and aldosterone were also measured. Hematocrits were used to calculate relative changes in plasma volume (% delta Vpl). Heart rate response to submaximal cycle ergometer exercise (35% peak oxygen uptake) was measured before and after water immersion. Water immersion induced significant increases in urine flow, Na clearance (CNa), and a 3-5% decrease in Vpl. Urine flow during immersion was greater (P < 0.05) in runners [2.4 (0.4) ml.min-1] compared to controls [1.3 (0.1) ml.min-1]. However, % delta Vpl, CCr, CNa and CH2O during immersion were not different (P > 0.05) between runners, swimmers, and controls. After 5 h of immersion, there was an increase (P < 0.05) in submaximal exercise heart rate of 9 (3) and 10 (3) beats.min-1 in both runners and controls, respectively, but no change (P > 0.05) was observed in swimmers.(ABSTRACT TRUNCATED AT 250 WORDS).

  18. Renal and cardiovascular responses to water immersion in trained runners and swimmers.

    PubMed

    Convertino, V A; Tatro, D L; Rogan, R B

    1993-01-01

    The purpose of this study was to determine if fluid-electrolyte, renal, hormonal, and cardiovascular responses during and after multi-hour water immersion were associated with aerobic training. Additionally, we compared these responses in those who trained in a hypogravic versus a 1-g environment. Seventeen men comprised three similarly aged groups: six long-distance runners, five competitive swimmers, and six untrained control subjects. Each subject underwent 5 h of immersion in water [mean (SE)] 36.0 (0.5) degrees C to the neck. Immediately before and at each hour of immersion, blood and urine samples were collected and analyzed for sodium (Na), potassium, osmolality, and creatinine (Cr). Plasma antidiuretic hormone and aldosterone were also measured. Hematocrits were used to calculate relative changes in plasma volume (% delta Vpl). Heart rate response to submaximal cycle ergometer exercise (35% peak oxygen uptake) was measured before and after water immersion. Water immersion induced significant increases in urine flow, Na clearance (CNa), and a 3-5% decrease in Vpl. Urine flow during immersion was greater (P < 0.05) in runners [2.4 (0.4) ml.min-1] compared to controls [1.3 (0.1) ml.min-1]. However, % delta Vpl, CCr, CNa and CH2O during immersion were not different (P > 0.05) between runners, swimmers, and controls. After 5 h of immersion, there was an increase (P < 0.05) in submaximal exercise heart rate of 9 (3) and 10 (3) beats.min-1 in both runners and controls, respectively, but no change (P > 0.05) was observed in swimmers.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8149929

  19. Response rate in the Study of Cardiovascular Risks in Adolescents – ERICA

    PubMed Central

    da Silva, Thiago Luiz Nogueira; Klein, Carlos Henrique; Souza, Amanda de Moura; Barufaldi, Laura Augusta; Abreu, Gabriela de Azevedo; Kuschnir, Maria Cristina Caetano; de Vasconcellos, Mauricio Teixeira Leite; Bloch, Katia Vergetti

    2016-01-01

    ABSTRACT OBJECTIVE To describe the response rate and characteristics of people who either took part or not in from the Study of Cardiovascular Risks in Adolescents (ERICA) , according to information subsets. METHODS ERICA is a school-based, nation-wide investigation with a representative sample of 12 to 17-year-old adolescents attending public or private schools in municipalities with over 100,000 inhabitants in Brazil. Response rate of eligible subjects were calculated according to macro-regions, sex, age, and type of school (public or private). We also calculated the percentages of replacement schools in comparison with the ones originally selected as per the sample design, according to the types of schools in the macro-regions. The subjects and non-subjects were compared according to sex, age, and average body mass indices (kg/m2). RESULTS We had 102,327 eligible adolescents enrolled in the groups drawn. The highest percentage of complete information was obtained for the subset of the questionnaire (72.9%). Complete information regarding anthropometric measurements and the ones from the questionnaire were obtained for 72.0% of the adolescents, and the combination of these data with the 24-hour dietary recall were obtained for 70.3% of the adolescents. Complete information from the questionnaire plus biochemical blood evaluation data were obtained for 52.5% of the morning session adolescents (selected for blood tests). The response percentage in private schools was higher than the one in public schools for most of the combination of information. The ratio of older and male adolescents non-participants was higher than the ratio among participants. CONCLUSIONS The response rate for non-invasive procedures was high. The response rate for blood collection – an invasive procedure that requires a 12-hour fasting period and the informed consent form from legal guardians – was lower. The response rate observed in public schools was lower than in the private ones, and

  20. β-adrenergic impact underlies the effect of mood and hedonic instrumentality on effort-related cardiovascular response.

    PubMed

    Silvestrini, Nicolas; Gendolla, Guido H E

    2011-05-01

    After habituation, participants were first induced into negative vs. positive moods and performed then an attention task with either low vs. high hedonic instrumentality of success. In the high-instrumentality condition participants expected to see a funny movie after success and an unpleasant movie after failure; in the low-instrumentality condition participants expected an unpleasant movie after success and a pleasant movie after failure. Effort-related cardiovascular response (ICG, blood pressure) was assessed during mood inductions and task performance. As predicted by the mood-behavior-model (Gendolla, 2000), responses of cardiac pre-ejection period (PEP) and systolic blood pressure were stronger in the high-instrumentality/negative-mood condition than in the other three cells. Here the high hedonic instrumentality of success justified the high effort that was perceived as necessary in a negative mood. Moreover, the PEP effects indicate that cardiovascular response was driven by beta-adrenergic impact on the heart rather than by vascular adjustments.

  1. Cardiovascular reflex responses to cutaneous and visceral stimuli in spinal man

    PubMed Central

    Corbett, J. L.; Frankel, H. L.; Harris, P. J.

    1971-01-01

    1. A study has been made of the effects of pinprick and a cold pack applied to the skin above and below the level of denervation, deep inspiration, squeezing the chest, and bladder percussion in non-bedridden patients with chronic, closed, complete, localized transection of the cervical spinal cord. Variables studied were blood pressure, heart rate, calf blood flow, hand blood flow and occluded vein pressure in the hand and foot. 2. Cutaneous stimuli above the lesion, mental arithmetic and noise from gunshot produced no response. 3. Pinprick and cold applied below the lesion usually produced an increase in mean arterial pressure, little change in pulse pressure or heart rate, clear decreases in calf and hand blood flow, and occasional venoconstriction. 4. Deep inspiration produced an initial rise in blood pressure and heart rate which was sometimes followed by a decrease in one or both. Squeezing the chest usually produced an increase in blood pressure and a decrease in heart rate. Both stimuli caused decreases in calf and hand blood flow and venoconstriction, the latter being more common after squeezing the chest. 5. Bladder percussion produced contraction of the wall of the bladder and this was regularly associated with increased arterial mean and pulse pressures, a decreased heart rate and calf and hand blood flow, and venoconstriction. The responses occurred whether or not the bladder was full and whether or not a rise of intravesical pressure occurred. PMID:5145725

  2. Cardiovascular responses of men and women to lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Montgomery, L. D.; Kirk, P. J.; Payne, P. A.; Gerber, R. L.; Newton, S. D.; Williams, B. A.

    1977-01-01

    Changes in blood flow and blood redistribution were measured by impedance plethysmography in the pelvic and leg regions of six male and four female subjects during three 5-min exposures to -20, -40, and -60 mm Hg lower body negative pressure (LBNP). Female subjects demonstrated significantly higher mean heart rate and lower leg blood flow indices than the male subjects during the recumbent control periods. Men had slightly higher mean resting systolic and diastolic blood pressures and higher mean control pelvic blood indices. Women demonstrated significantly less blood pooling in the legs and slightly less in the pelvic region than the men. All of the 18 tests with male subjects at -60 mm Hg were completed without initial signs of syncope, while only two of the tests with women were completed successfully without the subject exhibiting presyncopal conditions. Results indicate that impedance plethysmography can be used to measure segmental cardiovascular responses during LBNP and that females may be less tolerant to -60 mm Hg LBNP than males.

  3. Antigravity suit inflation: kidney function and cardiovascular and hormonal responses in men.

    PubMed

    Geelen, G; Kravik, S E; Hadj-Aissa, A; Leftheriotis, G; Vincent, M; Bizollon, C A; Sem-Jacobsen, C W; Greenleaf, J E; Gharib, C

    1989-02-01

    To investigate the effects of lower body positive pressure (LBPP) on kidney function while controlling certain cardiovascular and endocrine responses, seven men [35 +/- 2 (SE) yr] underwent 30 min of sitting and then 4.5 h of 70 degrees head-up tilt. An antigravity suit was applied (60 Torr legs, 30 Torr abdomen) during the last 3 h of tilt. A similar noninflation experiment was conducted where the suited subjects were tilted for 3.5 h. To provide adequate urine flow, the subjects were hydrated during the course of both experiments. Immediately after inflation, mean arterial pressure increased by 8 +/- 3 Torr and pulse rate decreased by 16 +/- 3 beats/min. Plasma renin activity and aldosterone were maximally suppressed (P less than 0.05) after 2.5 h of inflation. Plasma vasopressin decreased by 40-50% (P less than 0.05) and plasma sodium and potassium remained unchanged during both experiments. Glomerular filtration rate was not increased significantly by inflation, whereas inflation induced marked increases (P less than 0.05) in effective renal plasma flow (ERPF), urine flow, osmolar and free water clearances, and total and fractional sodium excretion. No such changes occurred during control. Thus, LBPP induces 1) a significant increase in ERPF and 2) significant changes in kidney excretory patterns similar to those observed during water immersion or the early phase of bed rest, situations that also result in central vascular volume expansion.

  4. Cardiovascular System Response to Carbon Dioxide and Exercise in Oxygen-Enriched Environment at 3800 m

    PubMed Central

    Liu, Guohui; Liu, Xiaopeng; Qin, Zhifeng; Gu, Zhao; Wang, Guiyou; Shi, Weiru; Wen, Dongqing; Yu, Lihua; Luo, Yongchang; Xiao, Huajun

    2015-01-01

    Background: This study explores the responses of the cardiovascular system as humans exercise in an oxygen-enriched room at high altitude under various concentrations of CO2. Methods: The study utilized a hypobaric chamber set to the following specifications: 3800 m altitude with 25% O2 and different CO2 concentrations of 0.5% (C1), 3.0% (C2) and 5.0% (C3). Subjects exercised for 3 min three times, separated by 30 min resting periods in the above-mentioned conditions, at sea level (SL) and at 3800 m altitude (HA). The changes of heart rate variability, heart rate and blood pressure were analyzed. Results: Total power (TP) and high frequency power (HF) decreased notably during post-exercise at HA. HF increased prominently earlier the post-exercise period at 3800 m altitude with 25% O2 and 5.0% CO2 (C3), while low frequency power (LF) changed barely in all tests. The ratios of LF/HF were significantly higher during post-exercise in HA, and lower after high intensity exercise in C3. Heart rate and systolic blood pressure increased significantly in HA and C3. Conclusions: Parasympathetic activity dominated in cardiac autonomic modulation, and heart rate and blood pressure increased significantly after high intensity exercise in C3. PMID:26393634

  5. Parity and Cardiovascular Disease Mortality: a Dose-Response Meta-Analysis of Cohort Studies.

    PubMed

    Lv, Haichen; Wu, Hongyi; Yin, Jiasheng; Qian, Juying; Ge, Junbo

    2015-08-24

    Parity has been shown to inversely associate with cardiovascular disease (CVD) mortality, but the evidence of epidemiological studies is still controversial. Therefore, we quantitatively assessed the relationship between parity and CVD mortality by summarizing the evidence from prospective studies. We searched MEDLINE (PubMed), EMBASE and ISI Web of Science databases for relevant prospective studies of parity and CVD mortality through the end of March 2015. Fixed- or random-effects models were used to estimate summary relative risks (RRs) and 95% confidence intervals (CIs). Heterogeneity among studies was assessed using the I(2) statistics. All statistical tests were two-sided. Ten prospective studies were included with a total of 994,810 participants and 16,601 CVD events. A borderline significant inverse association was observed while comparing parity with nulliparous, with summarized RR = 0.79 (95% CI: 0.60-1.06; I(2) = 90.9%, P < 0.001). In dose-response analysis, we observed a significant nonlinear association between parity number and CVD mortality. The greatest risk reduction appeared when the parity number reached four. The findings of this meta-analysis suggests that ever parity is inversely related to CVD mortality. Furthermore, there is a statistically significant nonlinear inverse association between parity number and CVD mortality.

  6. The Impact of Abdominal Obesity Status on Cardiovascular Response to the Mediterranean Diet

    PubMed Central

    Bédard, Alexandra; Dodin, Sylvie; Corneau, Louise; Lemieux, Simone

    2012-01-01

    We investigated the impact of abdominal obesity status on the cardiovascular response to a fully controlled 4-week isoenergetic Mediterranean diet (MedDiet). Thirty-eight abdominally obese individuals (waist circumference >102 cm in men and >88 cm in women) and thirty-one nonabdominally obese individuals were recruited and studied before and after the MedDiet. All analyses were adjusted for the slight decrease in body weight, which occurred during the MedDiet (mean: 0.9 ± 1.2 kg). A group by time interaction was noted for waist circumference (P = 0.02), abdominally obese subjects showing a significant decrease and nonabdominally obese subjects a nonsignificant increase (resp., −1.1 and +0.3%). The MedDiet resulted in decreases in total cholesterol, LDL-C, HDL-C, apolipoprotein B, A-1, and A-2, total cholesterol/HDL-C ratio, LDL-C/HDL-C ratio, and systolic and diastolic blood pressure (time effect: P < 0.05). For all variables related to glucose/insulin homeostasis, no change was observed except for a decrease in 2 h glucose concentrations (time effect: P = 0.03). No group by time interaction was observed in any of the metabolic variables studied. Results from our study suggest that the adoption of the MedDiet leads to beneficial metabolic effects, irrespective of the abdominal obesity status. PMID:23133745

  7. The matricellular protein thrombospondin-1 globally regulates cardiovascular function and responses to stress via CD47.

    PubMed

    Roberts, David D; Miller, Thomas W; Rogers, Natasha M; Yao, Mingyi; Isenberg, Jeffrey S

    2012-04-01

    Matricellular proteins play diverse roles in modulating cell behavior by engaging specific cell surface receptors and interacting with extracellular matrix proteins, secreted enzymes, and growth factors. Studies of such interactions involving thrombospondin-1 have revealed several physiological functions and roles in the pathogenesis of injury responses and cancer, but the relatively mild phenotypes of mice lacking thrombospondin-1 suggested that thrombospondin-1 would not be a central player that could be exploited therapeutically. Recent research focusing on signaling through its receptor CD47, however, has uncovered more critical roles for thrombospondin-1 in acute regulation of cardiovascular dynamics, hemostasis, immunity, and mitochondrial homeostasis. Several of these functions are mediated by potent and redundant inhibition of the canonical nitric oxide pathway. Conversely, elevated tissue thrombospondin-1 levels in major chronic diseases of aging may account for the deficient nitric oxide signaling that characterizes these diseases, and experimental therapeutics targeting CD47 show promise for treating such chronic diseases as well as acute stress conditions that are associated with elevated thrombospondin-1 expression.

  8. Effect of mildly attenuated heart rate response during treadmill exercise testing on cardiovascular outcome in healthy men and women.

    PubMed

    Maor, Elad; Kopel, Eran; Sidi, Yechezkel; Goldenberg, Ilan; Segev, Shlomo; Kivity, Shaye

    2013-11-01

    Attenuated heart rate (HR) response during exercise is associated with adverse cardiovascular outcome. The acceptable value for HR response is 85% of the age-predicted maximal HR (APMHR). This study hypothesized that mild attenuation of HR response during exercise among healthy subjects is associated with increased cardiovascular risk. The study population comprised 10,323 healthy men and women without known cardiovascular disease (CVD) or diabetes mellitus who underwent a yearly screening program and were followed up during a mean period of 4.3 years. Participants were grouped to 3 tertiles based on the percentage of their APMHR reached at the baseline stress test. The primary end point was the occurrence of CVD or cerebrovascular disease. A total of 1,015 incident cases of CVD occurred during follow-up. A multivariate Cox proportional hazards regression model showed that the CVD risk of subjects who reached 60% to 96% of their APMHR was 35% greater compared with those who reached their APMHR (p = 0.001). A subgroup analysis among subjects who reached 85% of their APMHR showed that even mildly attenuated heart response (in the range of 85% to 96% APMHR) was independently associated with 36% increase in CVD risk (p <0.001). In conclusion, attenuated HR response during exercise is a powerful and independent predictor of adverse cardiovascular events during long-term follow-up among healthy men and women. The prognostic implications of attenuated HR response in this population are apparent even with a minor decrease of the maximal HR to <96% of the APMHR.

  9. Leptin signaling in the nucleus of the solitary tract alters the cardiovascular responses to activation of the chemoreceptor reflex.

    PubMed

    Ciriello, John; Moreau, Jason M

    2012-10-01

    Circulating levels of leptin are elevated in individuals suffering from chronic intermittent hypoxia (CIH). Systemic and central administration of leptin elicits increases in sympathetic nervous activity (SNA), arterial pressure (AP), and heart rate (HR), and it attenuates the baroreceptor reflex, cardiovascular responses that are similar to those observed during CIH as a result of activation of chemoreceptors by the systemic hypoxia. Therefore, experiments were done in anesthetized Wistar rats to investigate the effects of leptin in nucleus of the solitary tract (NTS) on AP and HR responses, and renal SNA (RSNA) responses during activation of NTS neurons and the chemoreceptor reflex. Microinjection of leptin (5-100 ng; 20 nl) into caudal NTS pressor sites (l-glutamate; l-Glu; 0.25 M; 10 nl) elicited dose-related increases in AP, HR, and RSNA. Leptin microinjections (5 ng; 20 nl) into these sites potentiated the increase in AP and HR elicited by l-Glu. Additionally, bilateral injections of leptin (5 ng; 100 nl) into NTS potentiated the increase in AP and attenuated the bradycardia to systemic activation of the chemoreflex. In the Zucker obese rat, leptin injections into NTS neither elicited cardiovascular responses nor altered the cardiovascular responses to activation of the chemoreflex. Taken together, these data indicate that leptin exerts a modulatory effect on neuronal circuits within NTS that control cardiovascular responses elicited during the reflex activation of arterial chemoreceptors and suggest that increased AP and SNA observed in individuals with CIH may be due, in part, by leptin's effects on the chemoreflex at the level of NTS.

  10. Progress toward Producing Demand-Response-Ready Appliances

    SciTech Connect

    Hammerstrom, Donald J.; Sastry, Chellury

    2009-12-01

    This report summarizes several historical and ongoing efforts to make small electrical demand-side devices like home appliances more responsive to the dynamic needs of electric power grids. Whereas the utility community often reserves the word demand response for infrequent 2 to 6 hour curtailments that reduce total electrical system peak load, other beneficial responses and ancillary services that may be provided by responsive electrical demand are of interest. Historically, demand responses from the demand side have been obtained by applying external, retrofitted, controlled switches to existing electrical demand. This report is directed instead toward those manufactured products, including appliances, that are able to provide demand responses as soon as they are purchased and that require few, or no, after-market modifications to make them responsive to needs of power grids. Efforts to be summarized include Open Automated Demand Response, the Association of Home Appliance Manufacturer standard CHA 1, a simple interface being developed by the U-SNAP Alliance, various emerging autonomous responses, and the recent PinBus interface that was developed at Pacific Northwest National Laboratory.

  11. Pulmonary transcriptional response to ozone in healthy and cardiovascular compromised rat models.

    PubMed

    Ward, William O; Kodavanti, Urmila P

    2015-01-01

    The genetic cardiovascular disease (CVD) and associated metabolic impairments can influence the lung injury from inhaled pollutants. We hypothesized that comparative assessment of global pulmonary expression profile of healthy and CVD-prone rat models will provide mechanistic insights into susceptibility differences to ozone. The lung expression profiles of healthy Wistar Kyoto (WKY) and CVD-compromised spontaneously hypertensive (SH), stroke-prone SH (SHSP), obese SH heart failure (SHHF) and obese, atherosclerosis-prone JCR rats were analyzed using Affymetrix platform immediately after 4-h air or 1 ppm ozone exposure. At baseline, the JCR exhibited the largest difference in the number of genes among all strains when compared with WKY. Interestingly, the number of genes affected by ozone was inversely correlated with genes different at baseline relative to WKY. A cluster of NFkB target genes involved in cell-adhesion, antioxidant response, inflammation and apoptosis was induced in all strains, albeit at different levels (JCR < WKY < SHHF < SH < SHSP). The lung metabolic syndrome gene cluster indicated expressions in opposite directions for SHHF and JCR suggesting different mechanisms for common disease phenotype and perhaps obesity-independent contribution to exacerbated lung disease. The differences in expression of adrenergic receptors and ion-channel genes suggested distinct mechanisms by which ozone might induce protein leakage in CVD models, especially SHHF and JCR. Thus, the pulmonary response to ozone in CVD strains was likely linked to the defining gene expression profiles. Differential transcriptional patterns between healthy and CVD rat strains at baseline, and after ozone suggests that lung inflammation and injury might be influenced by multiple biological pathways affecting inflammation gene signatures.

  12. Cardiovascular and Perceptual Responses to an Ultraendurance Channel Swim: A Case Study.

    PubMed

    Judelson, Daniel A; Bagley, James R; Schumacher, Jennifer M; Wiersma, Lenny D

    2015-09-01

    Ultraendurance open water swimming presents unique physiological challenges. This case study aimed to describe cardiovascular and perceptual responses during a successful solo channel swim. Investigators followed a female swimmer's Catalina Channel (32.2 km) crossing, monitoring water temperature (T(water)) and air temperature (T(air)), distance remaining (DR), average velocity, and heart rate (HR(swim)) at regular intervals. Every 24 minutes, the swimmer reported perceived pain (on a scale of 0-10), rating of perceived exertion (RPE [scale of 6-20]), perceived thermal sensation (scale 0-8), and thirst (scale 1-9). Data are presented as mean ± SD where applicable. The participant finished in 9 hours, 2 minutes, and 48 seconds; T(water) averaged 19.1 ± 0.4ºC, and T(air) averaged 18.6 ± 0.9ºC. Her HR(swim) ranged from 148 to 155 beats/min, and thermal sensation ranged from 3 to 4. Pain inconsistently varied from 0 to 5 during the swim. The RPE remained between 12 and 14 for the first 8 hours, but increased dramatically near the end (reaching 18). Thirst sensation steadily increased throughout the swim, again reaching maximal values on completion. Physiologically and statistically significant correlations existed between thirst and DR (r = -0.905), RPE and HR(swim) (r = 0.741), RPE and DR (r = -0.694), and pain and DR (r = -0.671). The primary findings were that, despite fluctuations in perceptual stressors, the swimmer maintained a consistent exercise intensity as indicated by HR(swim); and during ultraendurance swimming, pain, RPE, and thirst positively correlated with distance swum. We hope these findings aid in the preparation and performance of future athletes by providing information on what swimmers may expect during an ultraendurance attempt and by increasing the understanding of physiological and perceptual responses during open water swimming. PMID:25819111

  13. Whole body plethysmography reveals differential ventilatory responses to ozone in rat models of cardiovascular disease.

    PubMed

    Dye, Janice A; Ledbetter, Allen D; Schladweiler, Mette C; Costa, Daniel L; Kodavanti, Urmila P

    2015-01-01

    To elucidate key factors of host susceptibility to air pollution, healthy and cardiovascular (CV)-compromised rats were exposed to air or ozone (O3) at 0.25, 0.5, or 1.0 ppm for 4 h. We hypothesized that rat strains with the least cardiac reserve would be most prone to develop significant health effects. Using flow whole body plethysmography (FWBP), ventilatory responses in healthy 3-month-old male rats [i.e. Wistar-Kyoto (WKY), Wistar (WIS), and Sprague-Dawley (SD) strains] were compared with hypertensive [i.e. spontaneously hypertensive (SH), fawn-hooded-hypertensive (FHH), and SH-stroke-prone (SHSP)] strains and obese [i.e. SH-heart failure-prone (SHHF) and JCR:LA-cp, atherosclerosis-prone (JCR)] strains. SH were slower to acclimate to the FWBP chambers. At 0-h post-air-exposure, SHSP and SHHF exhibited hyperpnea, indicative of cardiopulmonary insufficiency. At 0-h-post-O3, all but one strain showed significant concentration-dependent decreases in minute volume [MV = tidal volume (TV) × breathing frequency]. Comparing air with 1.0 ppm responses, MV declined 20-27% in healthy, 21-42% in hypertensive, and 33% in JCR rats, but was unchanged in SHHF rats. Penh increased significantly in all strains, with disproportionate increases in "responder" WKY and FHH strains. By 20 h, most changes had resolved, although Penh remained elevated in WKY, SH, and SHSP. Based on the effective dose estimates (O3 ppm × h × MV), the most CV-compromised (SHSP and SHHF) strains received significantly greater O3 lung deposition (25% and 40%, respectively). Data support epidemiologic associations that individuals with cardiopulmonary insufficiency are at greater risk for urban pollutant exposure due, in part, to enhanced lung deposition and exacerbation of hypoxia and pathophysiologic processes of heart failure. PMID:26667328

  14. Evaluation of cardiovascular protective effect of different apple varieties - Correlation of response with composition.

    PubMed

    Serra, Ana Teresa; Rocha, J; Sepodes, B; Matias, Ana A; Feliciano, Rodrigo P; de Carvalho, Agostinho; Bronze, Maria R; Duarte, Catarina M M; Figueira, M E

    2012-12-15

    Epidemiological evidence supports the concept that diets rich in fruits and vegetables promote health and attenuate or delay the onset of cardiovascular disease (CVD). In particular, a reduced risk of CVD has been associated with apple consumption, probably due to the cholesterol-lowering effect of the main bioactive compounds, namely fibre and polyphenols. In this work, the effect of diet supplementation with 20% of three Portuguese apple cultivars (Bravo de Esmolfe, Malápio Serra and Golden), containing distinct phenolic and fibre concentrations, on serum lipid profile and oxLDL of male Wistar rats fed a cholesterol-enriched diet (2%) was evaluated. After 30 days, only Bravo de Esmolfe apple was able to decrease significantly serum levels of triglycerides, total and LDL cholesterol concentrations (reductions of 27.2%, 21.0% and 20.4%, respectively, in relation to the cholesterol-enriched diet group, P<0.05). The levels of oxLDL were also significantly improved with the consumption of this apple variety (reductions of 20.0% and 11.9%, in relation to the cholesterol-enriched diet group and control group, respectively, P>0.05) as well as with Malapio da Serra apple (reductions of 9.8% in relation to the cholesterol-enriched diet group, P<0.05). Correlation of the bioactive response with chemical composition showed that catechin, epicatechin, procyanidin B1 and β-carotene are the major phytocompounds responsible for the cholesterol lowering ability of apples. The antioxidant potential may have also contributed to this beneficial effect.

  15. Aging alters muscle reflex control of autonomic cardiovascular responses to rhythmic contractions in humans.

    PubMed

    Sidhu, Simranjit K; Weavil, Joshua C; Venturelli, Massimo; Rossman, Matthew J; Gmelch, Benjamin S; Bledsoe, Amber D; Richardson, Russell S; Amann, Markus

    2015-11-01

    We investigated the influence of aging on the group III/IV muscle afferents in the exercise pressor reflex-mediated cardiovascular response to rhythmic exercise. Nine old (OLD; 68 ± 2 yr) and nine young (YNG; 24 ± 2 yr) males performed single-leg knee extensor exercise (15 W, 30 W, 80% max) under control conditions and with lumbar intrathecal fentanyl impairing feedback from group III/IV leg muscle afferents. Mean arterial pressure (MAP), cardiac output, leg blood flow (QL), systemic (SVC) and leg vascular conductance (LVC) were continuously determined. With no hemodynamic effect at rest, fentanyl blockade during exercise attenuated both cardiac output and QL ∼17% in YNG, while the decrease in cardiac output in OLD (∼5%) was significantly smaller with no impact on QL (P = 0.8). Therefore, in the face of similar significant ∼7% reduction in MAP during exercise with fentanyl blockade in both groups, LVC significantly increased ∼11% in OLD, but decreased ∼8% in YNG. The opposing direction of change was reflected in SVC with a significant ∼5% increase in OLD and a ∼12% decrease in YNG. Thus while cardiac output seems to account for the majority of group III/IV-mediated MAP responses in YNG, the impact of neural feedback on the heart may decrease with age and alterations in SVC become more prominent in mediating the similar exercise pressor reflex in OLD. Interestingly, in terms of peripheral hemodynamics, while group III/IV-mediated feedback plays a clear role in increasing LVC during exercise in the YNG, these afferents seem to actually reduce LVC in OLD. These peripheral findings may help explain the limited exercise-induced peripheral vasodilation often associated with aging.

  16. Contrasting effects of verapamil and amlodipine on cardiovascular stress responses in hypertension

    PubMed Central

    Lefrandt, Johan D; Heitmann, Jörg; Sevre, Knut; Castellano, Maurizio; Hausberg, Martin; Fallon, Maura; Urbigkeit, Anja; Rostrup, Morten; Agabiti-Rosei, Enrico; Rahn, Karl H; Murphy, Michael; Zannad, Faiez; de Kam, Pieter-Jan; Smit, Andries J

    2001-01-01

    Aims To compare the effects of two long-acting calcium antagonists of different types on cardiovascular stress responses in hypertension. Methods One-hundred and forty-five patients with mild to moderate hypertension and a mean (± s.e.mean) age of 51 ± 0.9 years received for 8 weeks the phenylalkylamine verapamil sustained release (240 mg) and the dihydropyridine amlodipine (5 mg) in a double-blind cross-over design, both after 4 weeks of placebo. Blood pressure, heart rate and plasma noradrenaline were monitored during 3 min of sustained isometric handgrip and 2 min of cold pressor. Results Blood pressure was equally reduced by both drugs. After 3 min handgrip, systolic blood pressure, heart rate and rate-pressure product were lower with verapamil compared with amlodipine. Verapamil attenuated the increases in systolic blood pressure (25 ± 2 vs 30 ± 2 mmHg, difference 4.6, 95% CI (1.0, 8.1), P < 0.01) and rate-pressure product (3.1 ± 0.2 vs 3.6 ± 0.3 × 103 mmHg × beats min−1, difference 0.5, 95% CI (0.1, 0.9), P < 0.01) during handgrip compared with amlodipine. Similar results were observed during cold pressor. Plasma noradrenaline levels were lower with verapamil compared with amlodipine at rest and after both tests, but the increases in plasma noradrenaline were not significantly different. Conclusions Verapamil is more effective in reducing blood pressure and rate-pressure product responses to stress compared with amlodipine. Although plasma noradrenaline is lower with verapamil at rest and after stress, the increase during stress is not different. PMID:11736880

  17. Aging alters muscle reflex control of autonomic cardiovascular responses to rhythmic contractions in humans.

    PubMed

    Sidhu, Simranjit K; Weavil, Joshua C; Venturelli, Massimo; Rossman, Matthew J; Gmelch, Benjamin S; Bledsoe, Amber D; Richardson, Russell S; Amann, Markus

    2015-11-01

    We investigated the influence of aging on the group III/IV muscle afferents in the exercise pressor reflex-mediated cardiovascular response to rhythmic exercise. Nine old (OLD; 68 ± 2 yr) and nine young (YNG; 24 ± 2 yr) males performed single-leg knee extensor exercise (15 W, 30 W, 80% max) under control conditions and with lumbar intrathecal fentanyl impairing feedback from group III/IV leg muscle afferents. Mean arterial pressure (MAP), cardiac output, leg blood flow (QL), systemic (SVC) and leg vascular conductance (LVC) were continuously determined. With no hemodynamic effect at rest, fentanyl blockade during exercise attenuated both cardiac output and QL ∼17% in YNG, while the decrease in cardiac output in OLD (∼5%) was significantly smaller with no impact on QL (P = 0.8). Therefore, in the face of similar significant ∼7% reduction in MAP during exercise with fentanyl blockade in both groups, LVC significantly increased ∼11% in OLD, but decreased ∼8% in YNG. The opposing direction of change was reflected in SVC with a significant ∼5% increase in OLD and a ∼12% decrease in YNG. Thus while cardiac output seems to account for the majority of group III/IV-mediated MAP responses in YNG, the impact of neural feedback on the heart may decrease with age and alterations in SVC become more prominent in mediating the similar exercise pressor reflex in OLD. Interestingly, in terms of peripheral hemodynamics, while group III/IV-mediated feedback plays a clear role in increasing LVC during exercise in the YNG, these afferents seem to actually reduce LVC in OLD. These peripheral findings may help explain the limited exercise-induced peripheral vasodilation often associated with aging. PMID:26386110

  18. Cardiovascular responses to water ingestion at rest and during isometric handgrip exercise.

    PubMed

    Mendonca, Goncalo V; Teixeira, Micael S; Pereira, Fernando D

    2012-07-01

    Water drinking activates sympathetic vasoconstriction in healthy young adults; however, this is not accompanied by a concomitant increase in resting blood pressure. It is not known whether the water pressor effect is unmasked by a physiological condition such as exercise. Therefore, we examined the effect of water ingestion (50 vs. 500 mL) on the cardiovascular and autonomic responses to isometric handgrip in 17 healthy participants (9 men, 8 women, aged 28.4 ± 9.7 years). Beat-to-beat blood pressure and R-R intervals were recorded in both conditions at rest (pre- and post-ingestion) and during handgrip at 30% of maximal voluntary contraction. R-R series were spectrally decomposed using an autoregressive approach. Water ingestion did not interact with the increase in mean arterial pressure (MAP) from rest to exercise, which was similar between conditions. In contrast, there was an overall bradycardic effect of water and this was accompanied by increased high frequency power (condition main effect, p < 0.05). When the differences in high frequency power between conditions were controlled for, MAP was significantly higher after drinking 500 mL of water (condition main effect, p < 0.05). In addition, water ingestion attenuated the increase in the low to high frequency power ratio from rest to handgrip (interaction effect, p < 0.05). In conclusion, the rise in blood pressure post-water ingestion is prevented both at rest and during isometric handgrip. Interestingly, this is not sustained after controlling for the enhanced vagal drive caused by water ingestion. Therefore, the mechanisms underlying this response most likely depend on reflex bradycardia of vagal origin.

  19. Cardiovascular fitness and haemodynamic responses to maximal cycle ergometer exercise test in children 6-8 years of age.

    PubMed

    Lintu, Niina; Tompuri, Tuomo; Viitasalo, Anna; Soininen, Sonja; Laitinen, Tomi; Savonen, Kai; Lindi, Virpi; Lakka, Timo A

    2014-01-01

    We investigated cardiovascular fitness and haemodynamic responses to maximal cycle ergometer exercise test in children. The participants were a population sample of 425 children (204 girls, 221 boys) aged 6-8 years. Heart rate (HR) and systolic blood pressure (SBP) were measured from the beginning of pre-exercise rest to the end of recovery period. We provided reference values for peak workload and changes in HR and SBP during and after maximal exercise test in girls and boys. Girls had a lower cardiovascular fitness, indicated by peak workload per body weight [mean (2 s) 2.7 (0.9) vs. 3.1 (1.0) W · kg(-1), P < 0.001] and lean mass [mean (2 s) 3.5 (0.9) vs. 3.8 (1.0) W · kg(-1), P < 0.001] than boys. Plateau or decline in SBP close to the end of the test was found in about third of children and was considered a normal SBP response. Girls had a slower HR decrease within 2 min after the test than boys [mean (2 s) 53 (18) vs. 59 (22) beats · min(-1), P < 0.001]. The results are useful for physicians and exercise physiologists to evaluate cardiovascular fitness and haemodynamic responses to exercise in children and to detect children with low exercise tolerance or abnormal haemodynamic responses to exercise.

  20. Effects of NASA-Fluid Loading Protocol on Cardiovascular Responses to Orthostatic Stress

    NASA Astrophysics Data System (ADS)

    Grinberg, Anna; Edgell, Heather; Gagne, Nathalie; Beavers, Keith; Hughson, Richard L.

    Fluid volume depletion is suspected to be a major contributor to orthostatic hypotension during prolonged bed-rest and spaceflight. Significant reductions in blood and plasma volumes are known to occur with spaceflight and bed-rest. The reductions are attributed to the hormonal responses reacting to a whole-body fluid shift resulting from the removal of the gravity vector seen in upright posture. NASA's proposed fluid loading protocol seeks to replace lost plasma volume by ingestion of salt tablets and water. The dosage is 15 ml/kg water with one 1-g salt tablet for each 125 ml of water over 2 hours. To examine the physiological effects of this fluid loading protocol on blood pressure regulation, seven subjects completed a 4-hour seated period with fluid loading occurring between 1.5 and 3.5 hours. Their responses to orthostatic stress were examined before and after fluid loading by simulating orthostasis in a lower-body negative-pressure (LBNP) box during a progressive test (0, -10, -20, -30, and -40 mmHg). Physiological variables such as heart rate, mean arterial pressure, systolic and diastolic blood pressure, pulse pressure, cardiac output, stroke volume, compliance, peripheral resistance, central venous pressure, and plasma volume were monitored. Data were analyzed using a twoway ANOVA, examining the effects of fluid loading and different levels of LBNP. Fluid loading did not influence cardiovascular variables as there were no significant differences in measured values between preand post-fluid loading conditions at each level of LBNP. This indicates that fluid loading does not increase plasma volume during four hour seated tests. The ingested water does not occupy the vascular bed, instead it may be mobilized to the extracellular space or the bladder. Fluid loading did not significantly affect responses to orthostatic stress, as there were no improvements in central venous pressure, stroke volume, and cardiac output during progressive levels of LBNP, and

  1. Acrolein Inhalation Alters Arterial Blood Gases and Triggers Carotid Body Mediated Cardiovascular Responses in Hypertensive Rats

    EPA Science Inventory

    Exposure to air pollution increases risk of cardiovascular morbidity and mortality, especially in individuals with underlying cardiopulmonary disease. While the mechanisms accounting for these effects are unclear, several epidemiological studies have reported decreases in oxygen ...

  2. Whole Body Plethysmography Reveals Differential Ventilatory Responses to Ozone in Rat Models of Cardiovascular Disease

    EPA Science Inventory

    Increasingly, urban air pollution is recognized as an important determinant of cardiovascular disease. Host susceptibility to air pollution can vary due to genetic predisposition and underlying disease. To elucidate key factors of host ...

  3. Pulmonary Transcriptional Response to Ozone in Healthy and Cardiovascular Compromised Rat Models

    EPA Science Inventory

    The genetic cardiovascular disease (CVD) and associated metabolic impairments can influence the lung injury from inhaled pollutants. We hypothesized that comparative assessment of global pulmonary expression profile of healthy and CVD-prone rat models will provide mechanistic ins...

  4. Fundus photography as a convenient tool to study microvascular responses to cardiovascular disease risk factors in epidemiological studies.

    PubMed

    De Boever, Patrick; Louwies, Tijs; Provost, Eline; Int Panis, Luc; Nawrot, Tim S

    2014-10-22

    The microcirculation consists of blood vessels with diameters less than 150 µm. It makes up a large part of the circulatory system and plays an important role in maintaining cardiovascular health. The retina is a tissue that lines the interior of the eye and it is the only tissue that allows for a non-invasive analysis of the microvasculature. Nowadays, high-quality fundus images can be acquired using digital cameras. Retinal images can be collected in 5 min or less, even without dilatation of the pupils. This unobtrusive and fast procedure for visualizing the microcirculation is attractive to apply in epidemiological studies and to monitor cardiovascular health from early age up to old age. Systemic diseases that affect the circulation can result in progressive morphological changes in the retinal vasculature. For example, changes in the vessel calibers of retinal arteries and veins have been associated with hypertension, atherosclerosis, and increased risk of stroke and myocardial infarction. The vessel widths are derived using image analysis software and the width of the six largest arteries and veins are summarized in the Central Retinal Arteriolar Equivalent (CRAE) and the Central Retinal Venular Equivalent (CRVE). The latter features have been shown useful to study the impact of modifiable lifestyle and environmental cardiovascular disease risk factors. The procedures to acquire fundus images and the analysis steps to obtain CRAE and CRVE are described. Coefficients of variation of repeated measures of CRAE and CRVE are less than 2% and within-rater reliability is very high. Using a panel study, the rapid response of the retinal vessel calibers to short-term changes in particulate air pollution, a known risk factor for cardiovascular mortality and morbidity, is reported. In conclusion, retinal imaging is proposed as a convenient and instrumental tool for epidemiological studies to study microvascular responses to cardiovascular disease risk factors.

  5. Fundus photography as a convenient tool to study microvascular responses to cardiovascular disease risk factors in epidemiological studies.

    PubMed

    De Boever, Patrick; Louwies, Tijs; Provost, Eline; Int Panis, Luc; Nawrot, Tim S

    2014-01-01

    The microcirculation consists of blood vessels with diameters less than 150 µm. It makes up a large part of the circulatory system and plays an important role in maintaining cardiovascular health. The retina is a tissue that lines the interior of the eye and it is the only tissue that allows for a non-invasive analysis of the microvasculature. Nowadays, high-quality fundus images can be acquired using digital cameras. Retinal images can be collected in 5 min or less, even without dilatation of the pupils. This unobtrusive and fast procedure for visualizing the microcirculation is attractive to apply in epidemiological studies and to monitor cardiovascular health from early age up to old age. Systemic diseases that affect the circulation can result in progressive morphological changes in the retinal vasculature. For example, changes in the vessel calibers of retinal arteries and veins have been associated with hypertension, atherosclerosis, and increased risk of stroke and myocardial infarction. The vessel widths are derived using image analysis software and the width of the six largest arteries and veins are summarized in the Central Retinal Arteriolar Equivalent (CRAE) and the Central Retinal Venular Equivalent (CRVE). The latter features have been shown useful to study the impact of modifiable lifestyle and environmental cardiovascular disease risk factors. The procedures to acquire fundus images and the analysis steps to obtain CRAE and CRVE are described. Coefficients of variation of repeated measures of CRAE and CRVE are less than 2% and within-rater reliability is very high. Using a panel study, the rapid response of the retinal vessel calibers to short-term changes in particulate air pollution, a known risk factor for cardiovascular mortality and morbidity, is reported. In conclusion, retinal imaging is proposed as a convenient and instrumental tool for epidemiological studies to study microvascular responses to cardiovascular disease risk factors. PMID

  6. The Implicit Positive and Negative Affect Test: Validity and Relationship with Cardiovascular Stress-Responses.

    PubMed

    van der Ploeg, Melanie M; Brosschot, Jos F; Thayer, Julian F; Verkuil, Bart

    2016-01-01

    Self-report, i.e., explicit, measures of affect cannot fully explain the cardiovascular (CV) responses to stressors. Measuring affect beyond self-report, i.e., using implicit measures, could add to our understanding of stress-related CV activity. The Implicit Positive and Negative Affect Test (IPANAT) was administered in two studies to test its ecological validity and relation with CV responses and self-report measures of affect. In Study 1 students (N = 34) viewed four film clips inducing anger, happiness, fear, or no emotion, and completed the IPANAT and the Positive And Negative Affect Scale at baseline and after each clip. Implicit negative affect (INA) was higher and implicit positive affect (IPA) was lower after the anger inducing clip and vice versa after the happiness inducing clip. In Study 2 students performed a stressful math task with (n = 14) or without anger harassment (n = 15) and completed the IPANAT and a Visual Analog Scale as an explicit measure afterwards. Systolic (SBP), diastolic (DBP) blood pressure, heart rate (HR), heart rate variability (HRV), and total peripheral resistance (TPR) were recorded throughout. SBP and DBP were higher and TPR was lower in the harassment condition during the task with a prolonged effect on SBP and DBP during recovery. As expected, explicit negative affect (ENA) was higher and explicit positive affect (EPA) lower after harassment, but ENA and EPA were not related to CV activity. Although neither INA nor IPA differed between the tasks, during both tasks higher INA was related to higher SBP, lower HRV and lower TPR and to slower recovery of DBP after both tasks. Low IPA was related to slower recovery of SBP and DBP after the tasks. Implicit affect was not related to recovery of HR, HRV, and TPR. In conclusion, the IPANAT seems to respond to film clip-induced negative and positive affect and was related to CV activity during and after stressful tasks. These findings support the theory that implicitly measured affect

  7. The Implicit Positive and Negative Affect Test: Validity and Relationship with Cardiovascular Stress-Responses.

    PubMed

    van der Ploeg, Melanie M; Brosschot, Jos F; Thayer, Julian F; Verkuil, Bart

    2016-01-01

    Self-report, i.e., explicit, measures of affect cannot fully explain the cardiovascular (CV) responses to stressors. Measuring affect beyond self-report, i.e., using implicit measures, could add to our understanding of stress-related CV activity. The Implicit Positive and Negative Affect Test (IPANAT) was administered in two studies to test its ecological validity and relation with CV responses and self-report measures of affect. In Study 1 students (N = 34) viewed four film clips inducing anger, happiness, fear, or no emotion, and completed the IPANAT and the Positive And Negative Affect Scale at baseline and after each clip. Implicit negative affect (INA) was higher and implicit positive affect (IPA) was lower after the anger inducing clip and vice versa after the happiness inducing clip. In Study 2 students performed a stressful math task with (n = 14) or without anger harassment (n = 15) and completed the IPANAT and a Visual Analog Scale as an explicit measure afterwards. Systolic (SBP), diastolic (DBP) blood pressure, heart rate (HR), heart rate variability (HRV), and total peripheral resistance (TPR) were recorded throughout. SBP and DBP were higher and TPR was lower in the harassment condition during the task with a prolonged effect on SBP and DBP during recovery. As expected, explicit negative affect (ENA) was higher and explicit positive affect (EPA) lower after harassment, but ENA and EPA were not related to CV activity. Although neither INA nor IPA differed between the tasks, during both tasks higher INA was related to higher SBP, lower HRV and lower TPR and to slower recovery of DBP after both tasks. Low IPA was related to slower recovery of SBP and DBP after the tasks. Implicit affect was not related to recovery of HR, HRV, and TPR. In conclusion, the IPANAT seems to respond to film clip-induced negative and positive affect and was related to CV activity during and after stressful tasks. These findings support the theory that implicitly measured affect

  8. The Implicit Positive and Negative Affect Test: Validity and Relationship with Cardiovascular Stress-Responses

    PubMed Central

    van der Ploeg, Melanie M.; Brosschot, Jos F.; Thayer, Julian F.; Verkuil, Bart

    2016-01-01

    Self-report, i.e., explicit, measures of affect cannot fully explain the cardiovascular (CV) responses to stressors. Measuring affect beyond self-report, i.e., using implicit measures, could add to our understanding of stress-related CV activity. The Implicit Positive and Negative Affect Test (IPANAT) was administered in two studies to test its ecological validity and relation with CV responses and self-report measures of affect. In Study 1 students (N = 34) viewed four film clips inducing anger, happiness, fear, or no emotion, and completed the IPANAT and the Positive And Negative Affect Scale at baseline and after each clip. Implicit negative affect (INA) was higher and implicit positive affect (IPA) was lower after the anger inducing clip and vice versa after the happiness inducing clip. In Study 2 students performed a stressful math task with (n = 14) or without anger harassment (n = 15) and completed the IPANAT and a Visual Analog Scale as an explicit measure afterwards. Systolic (SBP), diastolic (DBP) blood pressure, heart rate (HR), heart rate variability (HRV), and total peripheral resistance (TPR) were recorded throughout. SBP and DBP were higher and TPR was lower in the harassment condition during the task with a prolonged effect on SBP and DBP during recovery. As expected, explicit negative affect (ENA) was higher and explicit positive affect (EPA) lower after harassment, but ENA and EPA were not related to CV activity. Although neither INA nor IPA differed between the tasks, during both tasks higher INA was related to higher SBP, lower HRV and lower TPR and to slower recovery of DBP after both tasks. Low IPA was related to slower recovery of SBP and DBP after the tasks. Implicit affect was not related to recovery of HR, HRV, and TPR. In conclusion, the IPANAT seems to respond to film clip-induced negative and positive affect and was related to CV activity during and after stressful tasks. These findings support the theory that implicitly measured affect

  9. Cardiovascular Responses to an Isometric Handgrip Exercise in Females with Prehypertension

    PubMed Central

    Bond, Vernon; Curry, Bryan H.; Adams, Richard G.; Obisesan, Thomas; Pemminati, Sudhakar; Gorantla, Vasavi R.; Kadur, Kishan; Millis, Richard M.

    2016-01-01

    Background: Hypertensive individuals are known to exhibit greater increases in blood pressure during an isometric handgrip exercise (IHE) than their normotensive counterparts. Aim: This study tests the hypothesis that, compared to normotensive individuals, prehypertensive individuals exhibit an exaggerated response to IHE. Materials and Methods: In this study, the effects of IHE were compared in matched prehypertensive vs. normotensive healthy African-American females. Six healthy young adult African–American female university students were screened in a physician's office for blood pressure in the range of prehypertension, systolic blood pressure (SBP) 120–139 mmHg and diastolic blood pressure (DBP) 80–89 mmHg. Six young adult African–American women were also recruited to serve as a healthy normotensive control group with SBP ≤119 mmHg and DBP ≤79 mmHg. Cardiovascular fitness was determined by peak oxygen uptake (VO2 peak) measured during a progressive exercise test. Results: During the handgrip exercise, the prehypertensive group exhibited greater increases in SBP (from 139 ± 6 to 205 ± 11 mmHg, +48%) than the controls (from 132 ± 3 to 145 ± 3 mmHg, +10%); intergroup difference P < 0.001. The prehypertensive group also exhibited greater increases in DBP (from 77 ± 2 to 112 ± 5 mmHg, +46%) compared to the controls (from 72 ± 3 to 78 ± 4 mmHg, +8%); intergroup difference P < 0.001. The increase in systemic vascular resistance was also greater in the prehypertensive group (from 1713 ± 91 to 2807 ± 370 dyne.s.cm-5, +64%) than in the controls (from 1668 ± 80 to 1812 ± 169 dyne.s.cm-5, +9%); intergroup difference P < 0.05. Conclusion: These results suggest that blood pressure measurements performed during IHE may be a useful screening tool in evaluating prehypertensive individuals for antihypertensive treatments. PMID:27500128

  10. Studies on the desensitization of the central cardiovascular responses of histamine.

    PubMed

    Poulakos, J J; Gertner, S B

    1986-12-01

    Intraventricular administration of histamine (HA) in conscious freely moving rats produces a dose-dependent pressor response and bradycardia. These responses are diminished profoundly when a second injection of HA is given within a short time after the first injection. In this study, the specific HA H1 agonist, pyridylethylamine, and the specific H2 agonist, impromidine, were used to examine the nature of this tachyphylaxis. Blood pressure and heart rate were measured directly from indwelling carotid catheters, and drugs were administered in three consecutive intraventricular injections to conscious freely moving rats at 30-min intervals. HA, the H2 agonist, impromidine and the combined injection of pyridylethylamine and impromidine induced tachyphylaxis of the pressor response. The H1 agonist, pyridylethylamine and the HA-N-methyltransferase inhibitor, SKF-91488 (homodimaprit) did not show tachyphylaxis. Heart rate responses were more complex and only HA demonstrated tachyphylaxis of the bradycardia. It is concluded that the tachyphylaxis of the pressor response caused by repeated injections of HA results from the desensitization of central HA H2 receptors.

  11. Lessons from operational cardiovascular studies in space

    NASA Technical Reports Server (NTRS)

    Charles, J. B.; Yelle, J.; Sawin, C. F.

    1996-01-01

    The Space Shuttle program has produced a database of information on the cardiovascular responses to spaceflight, based on in-flight as well as pre- and post-flight assessments undertaken as part of the assessment of the health, safety, and efficiency of Shuttle crews. The methods used in routine cardiovascular assessments of Space Shuttle astronauts are reviewed, and the major findings of these investigations are presented.

  12. Cardiovascular and endocrine response to hemorrhage after. cap alpha. /sub 1/-blockade in lambs and ewes

    SciTech Connect

    Block, S.M.; Rose, J.C.; Ernest, J.M.; Flowe, K.; South, S.; Zimmerman, C.

    1987-02-01

    To evaluate the role of the ..cap alpha../sub 1/-adrenergic system in the response to hemorrhage during development, lambs and adult sheep were chronically catheterized and hemorrhaged after pretreatment with prazosin or vehicle. The adults became markedly more hypotensive after ..cap alpha../sub 1/-blockade and hemorrhage than after vehicle and hemorrhage, whereas the lambs were no more hypotensive when hemorrhaged after prazosin. In the adults and the lambs hemorrhage produced elevations in plasma renin activity and arginine vasopressin measured by radioimmunoassay. However, after prazosin, the adults had a far greater increase in arginine vasopressin levels than after vehicle treatment.

  13. The effects of high-intensity intermittent exercise training on cardiovascular response to mental and physical challenge.

    PubMed

    Heydari, Mehrdad; Boutcher, Yati N; Boutcher, Stephen H

    2013-02-01

    The purpose was to examine the effect of a 12-week exercise intervention on the cardiovascular and autonomic response of males to mental and physical challenge. Thirty four young overweight males were randomly assigned to either an exercise or control group. The exercise group completed a high-intensity intermittent exercise (HIIE) program three times per week for 12weeks. Cardiovascular response to the Stroop task was determined before and after the intervention by assessing heart rate (HR), stroke volume (SV), arterial stiffness, baroreflex sensitivity (BRS), and skeletal muscle blood flow. The exercise group improved their aerobic fitness levels by 17% and reduced their body weight by 1.6kg. Exercisers compared to controls experienced a significant reduction in HR (p<0.001) and a significant increase in SV (p<0.001) at rest and during Stroop and exercise. For exercisers, arterial stiffness significantly decreased at rest and during Stroop (p<0.01), whereas BRS was increased at rest and during Stroop (p<0.01). Forearm blood flow was significantly increased during the first two minutes of Stroop (p<0.05). HIIE induced significant cardiovascular and autonomic changes at rest and during mental and physical challenge after 12weeks of training. PMID:23220158

  14. Spectral analysis of resting cardiovascular variables and responses to oscillatory LBNP before and after 6 degree head dowm bedrest

    NASA Technical Reports Server (NTRS)

    Knapp, Charles F.; Evans, J. M.; Patwardhan, A.; Levenhagen, D.; Wang, M.; Charles, John B.

    1991-01-01

    A major focus of our research program is to develop noninvasive procedures for determining changes in cardiovascular function associated with the null gravity environment. We define changes in cardiovascular function to be (1) the result of the regulatory system operating at values different from 'normal' but with an overall control system basically unchanged by the null gravity exposure, or (2) the result of operating with a control system that has significantly different regulatory characteristics after an exposure. To this end, we have used a model of weightlessness that consisted of exposing humans to 2 hrs. in the launch position, followed by 20 hrs. of 6 deg head down bedrest. Our principal objective was to use this model to measure cardiovascular responses to the 6 deg head down bedrest protocol and to develop the most sensitive 'systems identification' procedure for indicating change. A second objective, related to future experiments, is to use the procedure in combination with experiments designed to determine the degree to which a regulatory pathway has been altered and to determine the mechanisms responsible for the changes.

  15. Exposure Assessment and Inflammatory Response Among Workers Producing Calcium Carbonate Nanomaterials

    NASA Astrophysics Data System (ADS)

    Cui, Ling

    . Modification is thought to be the primary emission source. It is discovered nanoparticles in the size range of 20-300nm dominate in this workplace, which consists of 90-98% of particle counts in the respirable fraction. Based on the sampling results from 2012, there was a strong relationship between number concentration in 5-25um range and the respirable mass concentration (r= 0.908); however, no such correlation was found between number concentration in nanoscale and respirable mass (r= 0.018). The deposited surface area in TB (r=0.66) and alveolar region (r=0.46) was modestly correlated with number concentration of particles in the nanoscale. A reduced FEV1 and increased BP were consistently found among medium-mass exposure compared to low-mass exposure, however no statistical significance was found. When comparing the four exposure metrics, we found number concentration and surface area concentration in general produce effects in similar direction, however opposite to mass concentration. Such observation is consistent with the correlation among these exposure metrics. Airway inflammatory responses presented a dose-response relationship using mass as exposure metric. The concentrations of IL1beta (p =0.043) and IL8 (p=0.008) in sputum among high mass-exposure group were statistically greater than that in low-mass exposure group. It suggested the inflammatory responses were associated with mass concentration of inhaled nanoparticle particles, which are mainly made up by agglomerated form of nanoparticles. At current stage, with limited understanding of the toxicological perspective of nanoparticle, a complete exposure assessment in nanoparticle facility needs to be conducted in both bulk- and nano-form.

  16. Roman Catholic beliefs produce characteristic neural responses to moral dilemmas.

    PubMed

    Christensen, Julia F; Flexas, Albert; de Miguel, Pedro; Cela-Conde, Camilo J; Munar, Enric

    2014-02-01

    This study provides exploratory evidence about how behavioral and neural responses to standard moral dilemmas are influenced by religious belief. Eleven Catholics and 13 Atheists (all female) judged 48 moral dilemmas. Differential neural activity between the two groups was found in precuneus and in prefrontal, frontal and temporal regions. Furthermore, a double dissociation showed that Catholics recruited different areas for deontological (precuneus; temporoparietal junction) and utilitarian moral judgments [dorsolateral prefrontal cortex (DLPFC); temporal poles], whereas Atheists did not (superior parietal gyrus for both types of judgment). Finally, we tested how both groups responded to personal and impersonal moral dilemmas: Catholics showed enhanced activity in DLPFC and posterior cingulate cortex during utilitarian moral judgments to impersonal moral dilemmas and enhanced responses in anterior cingulate cortex and superior temporal sulcus during deontological moral judgments to personal moral dilemmas. Our results indicate that moral judgment can be influenced by an acquired set of norms and conventions transmitted through religious indoctrination and practice. Catholic individuals may hold enhanced awareness of the incommensurability between two unequivocal doctrines of the Catholic belief set, triggered explicitly in a moral dilemma: help and care in all circumstances-but thou shalt not kill.

  17. Roman Catholic beliefs produce characteristic neural responses to moral dilemmas

    PubMed Central

    Flexas, Albert; de Miguel, Pedro; Cela-Conde, Camilo J.; Munar, Enric

    2014-01-01

    This study provides exploratory evidence about how behavioral and neural responses to standard moral dilemmas are influenced by religious belief. Eleven Catholics and 13 Atheists (all female) judged 48 moral dilemmas. Differential neural activity between the two groups was found in precuneus and in prefrontal, frontal and temporal regions. Furthermore, a double dissociation showed that Catholics recruited different areas for deontological (precuneus; temporoparietal junction) and utilitarian moral judgments [dorsolateral prefrontal cortex (DLPFC); temporal poles], whereas Atheists did not (superior parietal gyrus for both types of judgment). Finally, we tested how both groups responded to personal and impersonal moral dilemmas: Catholics showed enhanced activity in DLPFC and posterior cingulate cortex during utilitarian moral judgments to impersonal moral dilemmas and enhanced responses in anterior cingulate cortex and superior temporal sulcus during deontological moral judgments to personal moral dilemmas. Our results indicate that moral judgment can be influenced by an acquired set of norms and conventions transmitted through religious indoctrination and practice. Catholic individuals may hold enhanced awareness of the incommensurability between two unequivocal doctrines of the Catholic belief set, triggered explicitly in a moral dilemma: help and care in all circumstances—but thou shalt not kill. PMID:23160812

  18. CARDIOVASCULAR AND THERMOREGULATORY RESPONSES OF UNRESTRAINED RATS EXPOSED TO FILTERED OR UNFILTERED DIESEL EXHAUST

    EPA Science Inventory

    Diesel exhaust (DE) has been associated with adverse cardiovascular and pulmonary health effects. The relative contributions of the gas-phase and particulate (PM) components of DE are less well understood. We exposed WKY rats with or without implanted radiotransmitters to air or ...

  19. Central Cardiovascular Responses of Quadriplegic Subjects to Arm Exercise at Varying Levels of Oxygen Uptake.

    ERIC Educational Resources Information Center

    Figoni, Stephen F.

    The purpose of this study was to assess selected central cardiovascular functions of spinal cord injured, quadriplegic subjects at varying levels of oxygen uptake (VO sub 2). Subjects included 11 untrained, male college students with C5, C6, or C7 complete quadriplegia and 11 able-bodied reference subjects. Exercise was performed on a Monark cycle…

  20. A cardiovascular system model for lower-body negative pressure response

    NASA Technical Reports Server (NTRS)

    Mitchell, B. A., Jr.; Giese, R. P.

    1971-01-01

    Mathematical models used to study complex physiological control systems are discussed. Efforts were made to modify a model of the cardiovascular system for use in studying lower body negative pressure. A computer program was written which allows orderly, straightforward expansion to include exercise, metabolism (thermal stress), respiration, and other body functions.

  1. Community-Responsive Interventions to Reduce Cardiovascular Risk in American Indians

    ERIC Educational Resources Information Center

    Jobe, Jared B.; Adams, Alexandra K.; Henderson, Jeffrey A.; Karanja, Njeri; Lee, Elisa T.; Walters, Karina L.

    2012-01-01

    American Indian and Alaska Native (AI/AN) populations bear a heavy burden of cardiovascular disease (CVD), and they have the highest rates of risk factors for CVD, such as cigarette smoking, obesity, and diabetes, of any U.S. population group. Yet, few randomized controlled trials have been launched to test potential preventive interventions in…

  2. Histamine as a punisher in squirrel monkeys: effects of pentobarbital, chlordiazepoxide and H1- and H2-receptor antagonists on behavior and cardiovascular responses.

    PubMed

    Goldberg, S R

    1980-09-01

    Squirrel monkeys pressed a key under a two-component, 30-response fixed-ratio schedule of food presentation. In both nonpunishment and punishment components, every 30th key-pressing response resulted in food presentation. In the punishment component, the 11th and 22nd response in each 30-response fixed-ratio also produced a 200msec i.v. injection of 30 to 100 microgram/kg of histamine; this resulted in about an 80% suppression of responding in the punishment component. A second group of squirrel monkeys, with arterial catheters for monitoring of blood pressure and heart rate, received automatic i.v. injections of 30 and 100 microgram/kg of histamine; key presses had no programmed consequences. Mean arterial blood pressure decreased by 5 to 20 min Hg and heart rate increased by 60 to 120 beats/min after each injection of histamine. As an effective punisher, histamine was functionally similar to other noxious stimuli such as electric shock. Behavior suppressed by histamine could be markedly increased by presession i.m. treatment with pentobarbital (3-5.6 mg/kg) or chlordiazepoxide (10-30 mg/kg). Presession i.m. treatment with 1 to 3 mg/kg of the H1-receptor antagonist, diphenhydramine, reversed the punishment effects of histamine but only enhanced the cardiovascular effects of histamine. In contrast, 10 to 30 mg/kg of the H2-receptor antagonist, cimetidine, failed to reverse the punishment effects of histamine but markedly attenuated the cardiovascular effects of histamine. Thus, histamine's suppression of responding appeared to be an H1 effect and did not appear to be related to its effects on blood pressure and heart rate. PMID:6105208

  3. Blockade of 5-HT2A receptors suppresses hyperthermic but not cardiovascular responses to psychosocial stress in rats.

    PubMed

    Beig, M I; Baumert, M; Walker, F R; Day, T A; Nalivaiko, E

    2009-03-31

    The aim of this study was to determine whether 5-HT2A receptors mediate cardiovascular and thermogenic responses to acute psychological stresses. For this purpose, adult male Wistar hooded rats instrumented for telemetric recordings of either electrocardiogram (ECG) (n=12) or arterial pressure (n=12) were subjected, on different days, to four 15-min episodes of social defeat. Prior to stress, animals received s.c. injection of the selective 5-HT2A receptor antagonist SR-46349B (trans-4-((3Z)3-[(2-dimethylaminoethyl)oxyimino]-3-(2-fluorophenyl)propen-1-yl)-phenol, hemifumarate) (at doses of 0.3, 1.0 and 3.0 mg/kg) or vehicle. The drug had no effect on basal heart rate or heart rate variability indexes, arterial pressure, and core body temperature. Social defeat elicited significant and substantial tachycardic (347+/-7 to 500+/-7 bpm), pressor (77+/-4 to 97+/-4 mm Hg) and hyperthermic (37.0+/-0.3 to 38.5+/-0.1 degrees C) responses. Blockade of 5-HT2A receptors, at all doses of the antagonist, completely prevented stress-induced hyperthermia. In contrast, stress-induced cardiovascular responses were not affected by the blockade (except small reduction of tachycardia by the highest dose of the drug). We conclude that in rats, 5-HT2A receptors mediate stress-induced hyperthermic responses, but are not involved in the genesis of stress-induced rises in heart rate or arterial pressure, and do not participate in cardiovascular control at rest. PMID:19356699

  4. Blow fly responses to semiochemicals produced by decaying carcasses.

    PubMed

    Johansen, H; Solum, M; Knudsen, G K; Hågvar, E B; Norli, H R; Aak, A

    2014-03-01

    Volatiles from mouse carcasses in decay stages ranging from fresh to 33 days old were used to investigate oriented flight and landings in male and female blow flies of Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). Oriented flight increased significantly from 36% towards fresh carcasses to 68%, 61% and 65% towards carcasses aged 3 days, 6 days and 9 days, respectively. Carcasses aged 20 days and 33 days were significantly less attractive, achieving 51% and 41% attraction, respectively. No differences emerged between the sexes in oriented flight, but a significant increase in female landings at the most attractive carcasses was observed. Headspace collections from the different stages of decay showed a succession in the volatile profile emitted from the carcasses and identified nine chemicals which peak in quantity in concurrence with the most attractive stages of decay. Three of these chemicals also showed dose-response effects as indicated by a significant correlation between the amount present and the proportion of flies responding. Blow flies are important pests and efficient traps are needed. The significant interaction between fly sex and carcass age highlights behavioural differences between male and female blow flies which can be exploited in blow fly trapping. Three new volatile chemicals, butylated hydroxyl toluene, 3-hydroxy-2-butanone and nonanal, emitted from dead mice are suggested as potential attractants.

  5. Do behavioral responses mediate or moderate the relation between cardiovascular reactivity to stress and parental history of hypertension?

    PubMed

    Frazer, Nicole L; Larkin, Kevin T; Goodie, Jeffrey L

    2002-05-01

    To examine whether differences in behavioral responses to stress mediated or moderated the relation between cardiovascular response to stress and parental history of hypertension, 64 healthy undergraduates-16 men with hypertensive parents (PH+), 16 men without hypertensive parents (PH-), 16 PH+ women, and 16 PH- women-participated in a mental arithmetic task, mirror tracing task, and 2 interpersonal role plays. PH+ participants exhibited higher resting heart rates than PH- participants and higher resting systolic blood pressures (SBPs) than PH- women. PH+ participants exhibited greater SBP responses to tasks and engaged in more negative verbal and nonverbal behavior across tasks than PH- counterparts. Differences in behavioral responding neither mediated nor moderated the observed relation between parental history status and SBP response to stress.

  6. Evaluation of the ethanol antagonist' Ro15-4513 on cardiovascular and metabolic responses induced by ethanol

    SciTech Connect

    Lerner, M.R.; Gauvin, D.V.; Holloway, F.A.; Wilson, M.F.; Brackett, D.J. Veterans Affairs Medical Center, Oklahoma City, OK )

    1992-02-26

    The putative ethanol antagonist Ro15-4513 has been reported to attenuate many behavioral responses induced by ethanol, including motor coordination, narcosis, ethanol self administration and intake, and anticonvulsant actions. This study was designed to study the effect of Ro15-4513 on cardiovascular and metabolic responses elicited by intragastric ethanol in conscious rats. Four groups of rats were catheterized under enflurane anesthesia and allowed to regain consciousness. Each group was given either 3.2, 10.0, or 32.0 mg/kg Ro15-4513 or equivalent Tween (i.p.) following ethanol. Ro15-4513 had no effect at any concentration on the decreases in mean arterial pressure, cardiac output, central venous pressure, respiration rate, and cardiac stroke volume and the increases in systemic vascular resistance, heart rate, and glucose evoked by the ethanol challenge. Blood alcohol concentrations measured throughout the study were not affected by any concentration of Ro15-4513. These data suggest that even though Ro15-4513 has significant effects on behavioral responses induced by ethanol it has no effect on the cardiovascular and metabolic responses elicited during ethanol intoxication.

  7. Does mental arithmetic before head up tilt have an effect on the orthostatic cardiovascular and hormonal responses?

    NASA Astrophysics Data System (ADS)

    Goswami, Nandu; Lackner, Helmut Karl; Papousek, Ilona; Montani, Jean-Pierre; Jezova, Daniela; Hinghofer-Szalkay, Helmut G.

    2011-05-01

    Passive head up tilt (HUT) and mental arithmetic (MA) are commonly used for providing mental and orthostatic challenges, respectively. In animal experiments, even a single exposure to a stressor has been shown to modify the response to subsequent stress stimulus. We investigated whether MA applied before HUT elicits synergistic responses in orthostatic heart rate (HR), cardiac output (CO), heart rate variability and arterial blood pressure. The 15 healthy young males were subjected to two randomized protocols: (a) HUT and (b) HUT preceded by MA, with sessions randomized and ≥2 weeks apart. Beat to beat continuous hemodynamic variables were measured and saliva samples taken for hormonal assay. HUT alone increased HR from 59±7 (baseline) to 80±10 bpm (mean±SD) and mean blood pressure (MBP) from 88±10 to 91±14 mmHg. HUT results after MA were not different from those with HUT alone. The activity of alpha amylase showed differences during the experiments irrespective of the protocols. We conclude that mental challenge does not affect orthostatic cardiovascular responses when applied before; the timing of mental loading seems to be critical if it is intended to alter cardiovascular responses to upright standing.

  8. Characterisation of an oxidative response inhibitor produced by Streptococcus pneumoniae.

    PubMed Central

    Perry, F. E.; Elson, C. J.; Mitchell, T. J.; Andrew, P. W.; Catterall, J. R.

    1994-01-01

    BACKGROUND--Pneumonia caused by infection with Streptococcus pneumoniae is still a major clinical problem. Reactive oxygen species contribute to the killing of these bacteria by polymorphonuclear leucocytes (PMNs). Defence mechanisms of Str pneumoniae which counter reactive oxygen species are characterised. METHODS--PMNs were stimulated with phorbol myristate acetate (PMA) in the presence and absence of Str pneumoniae and supernatants from them, and superoxide (O2-) production was measured by the reduction of ferricytochrome c. RESULTS--Streptococcus pneumoniae, but not Klebsiella pneumoniae or Staphylococcus aureus, inhibited PMA stimulated superoxide production by PMNs. Washed PMNs which had been preincubated with Str pneumoniae autolysis phase supernatants also exhibited depressed H2O2 production in response to PMA. The inhibitory activity was not attributable to non-specific cytotoxicity as assessed by release of the cytoplasmic enzyme lactate dehydrogenase, nor did the supernatants inhibit PMA stimulated degranulation of PMNs. Fractionation of the autolysis phase supernatants revealed inhibitory activity in both the fractions greater than and less than 10 kD. Like pneumolysin the inhibitory activity was heat sensitive. However, both a parent and pneumolysin negative mutant Str pneumoniae, and autolysis phase supernatants from them, inhibited PMN superoxide production. Antisera to pneumolysin failed to abrogate the inhibitory effect of intact Str pneumoniae or autolysis phase supernatants from types 1 or 14 Str pneumoniae. CONCLUSIONS--The inhibitory effect of Str pneumoniae on the respiratory burst of PMNs is not shared by two other common lung pathogens. The existence of a novel inhibitor of the PMN respiratory burst, distinct from pneumolysin, has been demonstrated. The inhibitor is specific for the respiratory burst and is active both in the logarithmic phase of growth and during autolysis. PMID:8066562

  9. Effect of short-term weight loss on mental stress-induced cardiovascular and pro-inflammatory responses in women

    PubMed Central

    Endrighi, Romano; Hamer, Mark; Hackett, Ruth A.; Carvalho, Livia A.; Jackson, Sarah E.; Wardle, Jane; Steptoe, Andrew

    2015-01-01

    Abstract Epidemiologic evidence links psychosocial stress with obesity but experimental studies examining the mechanisms that mediates the effect of stress on adiposity are scarce. The aim of this study was to investigate whether changes in adiposity following minimal weight loss affect heightened stress responses in women, and examine the role of the adipokine leptin in driving inflammatory responses. Twenty-three overweight or obese, but otherwise healthy, women (M age = 30.41 ± 8.0 years; BMI = 31.9 ± 4.1 kg/m2) completed standardized acute mental stress before and after a 9-week calorie restriction program designed to modify adiposity levels. Cardiovascular (blood pressure and heart rate) and inflammatory cytokines (leptin and interleukin-6; IL-6) responses to mental stress were assessed several times between baseline and a 45-min post-stress recovery period. There were modest changes in adiposity measures while the adipokine leptin was markedly reduced (−27%) after the intervention. Blood pressure reactivity was attenuated (−3.38 ± 1.39 mmHg) and heart rate recovery was improved (2.07 ± 0.96 Bpm) after weight loss. Blood pressure responses were inversely associated with changes in waist to hip ratio post intervention. Decreased levels of circulating leptin following weight loss were inversely associated with the IL-6 inflammatory response to stress (r = −0.47). We offered preliminary evidence suggesting that modest changes in adiposity following a brief caloric restriction program may yield beneficial effect on cardiovascular stress responses. In addition, reductions in basal leptin activity might be important in blunting pro-inflammatory responses. Large randomized trials of the effect of adiposity on autonomic responses are thus warranted. PMID:26181102

  10. Effect of short-term weight loss on mental stress-induced cardiovascular and pro-inflammatory responses in women.

    PubMed

    Endrighi, Romano; Hamer, Mark; Hackett, Ruth A; Carvalho, Livia A; Jackson, Sarah E; Wardle, Jane; Steptoe, Andrew

    2015-01-01

    Epidemiologic evidence links psychosocial stress with obesity but experimental studies examining the mechanisms that mediates the effect of stress on adiposity are scarce. The aim of this study was to investigate whether changes in adiposity following minimal weight loss affect heightened stress responses in women, and examine the role of the adipokine leptin in driving inflammatory responses. Twenty-three overweight or obese, but otherwise healthy, women (M age = 30.41 ± 8.0 years; BMI = 31.9 ± 4.1 kg/m(2)) completed standardized acute mental stress before and after a 9-week calorie restriction program designed to modify adiposity levels. Cardiovascular (blood pressure and heart rate) and inflammatory cytokines (leptin and interleukin-6; IL-6) responses to mental stress were assessed several times between baseline and a 45-min post-stress recovery period. There were modest changes in adiposity measures while the adipokine leptin was markedly reduced (-27%) after the intervention. Blood pressure reactivity was attenuated (-3.38 ± 1.39 mmHg) and heart rate recovery was improved (2.07 ± 0.96 Bpm) after weight loss. Blood pressure responses were inversely associated with changes in waist to hip ratio post intervention. Decreased levels of circulating leptin following weight loss were inversely associated with the IL-6 inflammatory response to stress (r = -0.47). We offered preliminary evidence suggesting that modest changes in adiposity following a brief caloric restriction program may yield beneficial effect on cardiovascular stress responses. In addition, reductions in basal leptin activity might be important in blunting pro-inflammatory responses. Large randomized trials of the effect of adiposity on autonomic responses are thus warranted. PMID:26181102

  11. Effect of short-term weight loss on mental stress-induced cardiovascular and pro-inflammatory responses in women.

    PubMed

    Endrighi, Romano; Hamer, Mark; Hackett, Ruth A; Carvalho, Livia A; Jackson, Sarah E; Wardle, Jane; Steptoe, Andrew

    2015-01-01

    Epidemiologic evidence links psychosocial stress with obesity but experimental studies examining the mechanisms that mediates the effect of stress on adiposity are scarce. The aim of this study was to investigate whether changes in adiposity following minimal weight loss affect heightened stress responses in women, and examine the role of the adipokine leptin in driving inflammatory responses. Twenty-three overweight or obese, but otherwise healthy, women (M age = 30.41 ± 8.0 years; BMI = 31.9 ± 4.1 kg/m(2)) completed standardized acute mental stress before and after a 9-week calorie restriction program designed to modify adiposity levels. Cardiovascular (blood pressure and heart rate) and inflammatory cytokines (leptin and interleukin-6; IL-6) responses to mental stress were assessed several times between baseline and a 45-min post-stress recovery period. There were modest changes in adiposity measures while the adipokine leptin was markedly reduced (-27%) after the intervention. Blood pressure reactivity was attenuated (-3.38 ± 1.39 mmHg) and heart rate recovery was improved (2.07 ± 0.96 Bpm) after weight loss. Blood pressure responses were inversely associated with changes in waist to hip ratio post intervention. Decreased levels of circulating leptin following weight loss were inversely associated with the IL-6 inflammatory response to stress (r = -0.47). We offered preliminary evidence suggesting that modest changes in adiposity following a brief caloric restriction program may yield beneficial effect on cardiovascular stress responses. In addition, reductions in basal leptin activity might be important in blunting pro-inflammatory responses. Large randomized trials of the effect of adiposity on autonomic responses are thus warranted.

  12. Health monitoring of Japanese payload specialist: Autonomic nervous and cardiovascular responses under reduced gravity condition (L-0)

    NASA Technical Reports Server (NTRS)

    Sekiguchi, Chiharu

    1993-01-01

    In addition to health monitoring of the Japanese Payload Specialists (PS) during the flight, this investigation also focuses on the changes of cardiovascular hemodynamics during flight which will be conducted under the science collaboration with the Lower Body Negative Pressure (LBNP) Experiment of NASA. For the Japanese, this is an opportunity to examine firsthand the effects of microgravity of human physiology. We are particularly interested in the adaption process and how it relates to space motion sickness and cardiovascular deconditioning. By comparing data from our own experiment to data collected by others, we hope to understand the processes involved and find ways to avoid these problems for future Japanese astronauts onboard Space Station Freedom and other Japanese space ventures. The primary objective of this experiment is to monitor the health condition of Japanese Payload Specialists to maintain a good health status during and after space flight. The second purpose is to investigate the autonomic nervous system's response to space motion sickness. To achieve this, the function of the autonomic nervous system will be monitored using non-invasive techniques. Data obtained will be employed to evaluate the role of autonomic nervous system in space motion sickness and to predict susceptibility to space motion sickness. The third objective is evaluation of the adaption process of the cardiovascular system to microgravity. By observation of the hemodynamics using an echocardiogram we will gain insight on cardiovascular deconditioning. The last objective is to create a data base for use in the health care of Japanese astronauts by obtaining control data in experiment L-O in the SL-J mission.

  13. Neural regulation of cardiovascular response to exercise: role of central command and peripheral afferents.

    PubMed

    Nobrega, Antonio C L; O'Leary, Donal; Silva, Bruno Moreira; Marongiu, Elisabetta; Piepoli, Massimo F; Crisafulli, Antonio

    2014-01-01

    During dynamic exercise, mechanisms controlling the cardiovascular apparatus operate to provide adequate oxygen to fulfill metabolic demand of exercising muscles and to guarantee metabolic end-products washout. Moreover, arterial blood pressure is regulated to maintain adequate perfusion of the vital organs without excessive pressure variations. The autonomic nervous system adjustments are characterized by a parasympathetic withdrawal and a sympathetic activation. In this review, we briefly summarize neural reflexes operating during dynamic exercise. The main focus of the present review will be on the central command, the arterial baroreflex and chemoreflex, and the exercise pressure reflex. The regulation and integration of these reflexes operating during dynamic exercise and their possible role in the pathophysiology of some cardiovascular diseases are also discussed. PMID:24818143

  14. Dietary potassium: a key mediator of the cardiovascular response to dietary sodium chloride.

    PubMed

    Kanbay, Mehmet; Bayram, Yeter; Solak, Yalcin; Sanders, Paul W

    2013-01-01

    Potassium and sodium share a yin/yang relationship in the regulation of blood pressure (BP). BP is directly associated with the total body sodium and negatively correlated with the total body potassium. Epidemiologic, experimental, and clinical studies have shown that potassium is a significant regulator of BP and further improves cardiovascular outcomes. Hypertensive cardiovascular damage, stroke, and stroke-related death are accelerated by salt intake but might be curbed by increasing dietary potassium intake. The antihypertensive effect of potassium supplementation appears to occur through several mechanisms that include regulation of vascular sensitivity to catecholamines, promotion of natriuresis, limiting plasma renin activity, and improving endothelial function. In the absence of chronic kidney disease, the combined evidence suggests that a diet rich in potassium content serves a vasculoprotective function, particularly in the setting of salt-sensitive hypertension and prehypertension.

  15. Characterization of fluid physics effects on cardiovascular response to microgravity (G-572)

    NASA Technical Reports Server (NTRS)

    Pantalos, George M.; Bennett, Thomas E.; Sharp, M. Keith; Woodruff, Stewart; Oleary, Sean; Gillars, Kevin; Lemon, Mark; Sojka, Jan

    1995-01-01

    The investigation of cardiovascular adaptation to space flight has seen substantial advancement in the last several years. In-flight echocardiographic measurements of astronaut cardiac function on the Space Shuttle have documented an initial increase, followed by a progressive reduction in both left ventricular volume index and stroke volume with a compensatory increase in heart rate to maintain cardiac output. To date, the reduced cardiac size and stroke volume have been presumed to be the consequence of the reduction in circulating fluid volume within a few days after orbital insertion. However, no specific mechanism for the reduced stroke volume has been identified. The following investigation proposes the use of a hydraulic model of the cardiovascular system to examine the possibility that the observed reduction in stroke volume may, in part, be related to fluid physics effects on heart function. The automated model is being prepared to fly as a Get Away Special (GAS) payload within the next year.

  16. Strength and power training did not modify cardiovascular responses to aerobic exercise in elderly subjects.

    PubMed

    Kanegusuku, H; Queiroz, A C C; Chehuen, M R; Costa, L A R; Wallerstein, L F; Mello, M T; Ugrinowitsch, C; Forjaz, C L M

    2011-09-01

    Resistance training increases muscle strength in older adults, decreasing the effort necessary for executing physical tasks, and reducing cardiovascular load during exercise. This hypothesis has been confirmed during strength-based activities, but not during aerobic-based activities. This study determined whether different resistance training regimens, strength training (ST, constant movement velocity) or power training (PT, concentric phase performed as fast as possible) can blunt the increase in cardiovascular load during an aerobic stimulus. Older adults (63.9 ± 0.7 years) were randomly allocated to: control (N = 11), ST (N = 13, twice a week, 70-90% 1-RM) and PT (N = 15, twice a week, 30-50% 1-RM) groups. Before and after 16 weeks, oxygen uptake (VO(2)), systolic blood pressure (SBP), heart rate (HR), and rate pressure product (RPP) were measured during a maximal treadmill test. Resting SBP and RPP were similarly reduced in all groups (combined data = -5.7 ± 1.2 and -5.0 ± 1.7%, respectively, P < 0.05). Maximal SBP, HR and RPP did not change. The increase in measured VO(2), HR and RPP for the increment in estimated VO(2) (absolute load) decreased similarly in all groups (combined data = -9.1 ± 2.6, -14.1 ± 3.9, -14.2 ± 3.0%, respectively, P < 0.05), while the increments in the cardiovascular variables for the increase in measured VO(2) did not change. In elderly subjects, ST and PT did not blunt submaximal or maximal HR, SBP and RPP increases during the maximal exercise test, showing that they did not reduce cardiovascular stress during aerobic tasks.

  17. Cardiovascular responses of semi-arboreal snakes to chronic, intermittent hypergravity

    NASA Technical Reports Server (NTRS)

    Lillywhite, H. B.; Ballard, R. E.; Hargens, A. R.

    1996-01-01

    Cardiovascular functions were studied in semi-arboreal rat snakes (Elaphe obsoleta) following long-term, intermittent exposure to +1.5 Gz (head-to-tail acceleration) on a centrifuge. Snakes were held in a nearly straight position within horizontal plastic tubes during periods of centrifugation. Centrifugal acceleration, therefore, subjected snakes to a linear force gradient with the maximal force being experienced at the tail. Compared to non-centrifuged controls, Gz-acclimated snakes showed greater increases of heart rate during head-up tilt or acceleration, greater sensitivity of arterial pressure to circulating catecholamines, higher blood levels of corticosterone, and higher blood ratios of prostaglandin F 2 alpha/prostaglandin E2. Cardiovascular tolerance to increased gravity during graded Gz acceleration was measured as the maximum (caudal) acceleration force at which carotid arterial blood flow became null. When such tolerances were adjusted for effects of body size and other continuous variables incorporated into an analysis of covariance, the difference between the adjusted mean values of control and acclimated snakes (2.37 and 2.84 Gz, respectively) corresponded closely to the 0.5 G difference between the acclimation G (1.5) and Earth gravity (1.0). As in other vertebrates, cardiovascular tolerance to Gz stress tended to be increased by acclimation, short body length, high arterial pressure, and comparatively large blood volume. Voluntary body movements were important for promoting carotid blood flow at the higher levels of Gz stress.

  18. Role of Endogenous Factors in Response of Erythrocyte Membrane in Patients with Cardiovascular Diseases under Conditions of Ischemic Exposure.

    PubMed

    Pivovarov, Yu I; Kuznetsova, E E; Koryakina, L B; Gorokhova, V G; Kuril'skaya, T E

    2015-05-01

    We studied specific features of erythrocyte membrane response to short-term occlusion of the brachial artery in patients with cardiovascular pathology. Under ischemic conditions, processes of sorption were primarily intensified in patients with effort angina and processes of hemoglobin binding with erythrocyte membrane predominated in patients with essential hypertension. These changes in the cell membrane were related to modulation of aggregation properties of erythrocytes (in patients with angina) and plasminogen activity (in patients with essential hypertension). They can also be associated with changes in glucose levels (effort angina) and uric acid (essential hypertension) whose effects can be significantly modified by other endogenous factors.

  19. β-adrenergic impact underlies the effect of mood and hedonic instrumentality on effort-related cardiovascular response.

    PubMed

    Silvestrini, Nicolas; Gendolla, Guido H E

    2011-05-01

    After habituation, participants were first induced into negative vs. positive moods and performed then an attention task with either low vs. high hedonic instrumentality of success. In the high-instrumentality condition participants expected to see a funny movie after success and an unpleasant movie after failure; in the low-instrumentality condition participants expected an unpleasant movie after success and a pleasant movie after failure. Effort-related cardiovascular response (ICG, blood pressure) was assessed during mood inductions and task performance. As predicted by the mood-behavior-model (Gendolla, 2000), responses of cardiac pre-ejection period (PEP) and systolic blood pressure were stronger in the high-instrumentality/negative-mood condition than in the other three cells. Here the high hedonic instrumentality of success justified the high effort that was perceived as necessary in a negative mood. Moreover, the PEP effects indicate that cardiovascular response was driven by beta-adrenergic impact on the heart rather than by vascular adjustments. PMID:21382436

  20. Extending producer responsibility up and down the supply chain, challenges and limitation.

    PubMed

    Scheijgrond, Jan-Willem

    2011-09-01

    Producers are given increasing responsibility by governmental organizations to address environmental and human rights issues along the supply chain. While producers indeed have a responsibility to address these issues, governments' expectations of producers are often too high and in some cases unrealistic. Ruggie's framework to protect, respect and remedy provides a useful tool to determine the responsibilities of government and business in relation to human rights. If it is applied to product-related environmental aspects, which affect human rights, it offers a good tool to evaluate whether producer responsibility has been implemented in a way to institutionally align business and governments. An analysis of extended producer responsibility up and down the supply chain on the basis of waste electrical and electronic equipment (WEEE) legislation, REACH legislation and conflict minerals shows that such alignment has not been achieved. PMID:21771871

  1. Cardiovascular responses to peripheral chemoreflex activation and comparison of different methods to evaluate baroreflex gain in conscious mice using telemetry.

    PubMed

    Braga, Valdir A; Burmeister, Melissa A; Sharma, Ram V; Davisson, Robin L

    2008-10-01

    Peripheral chemoreceptors located in the carotid bodies are the primary sensors of systemic hypoxia. Although the pattern of responses elicited by peripheral chemoreceptor activation is well established in rats, lambs, and rabbits, the cardiovascular responses to peripheral chemoreflex activation in conscious mice have not been delineated. Here we report that stimulation of peripheral chemoreceptors by potassium cyanide (KCN) in conscious mice elicits a unique biphasic response in blood pressure that is characterized by an initial and robust rise followed by a decrease in blood pressure, which is accompanied by a marked reduction in heart rate. The depressor and bradycardic responses to KCN were abolished by muscarinic receptor blockade with atropine, and the pressor response was abolished by alpha-adrenergic receptor blockade with prazosin, suggesting that vagal and sympathetic drive to the heart and sympathetic drive to the vasculature mediate these cardiovascular responses. These studies characterized the chemoreflex in conscious mice and established the reliability of using them for studying hypoxia-related diseases such as obstructive sleep apnea. In another series of experiments, two methods for analyzing baroreflex sensitivity were compared: the classical pharmacological approach using phenylephrine and sodium nitroprusside (i.e., the Oxford technique) or the sequence method for analyzing spontaneous baroreflex activity. Our findings indicate that both methods are reliable, and the sequence method certainly has its benefits as a predictive tool in the context of long-term noninvasive studies using telemetry. However, for absolute determination of baroreflex function, analysis of spontaneous baroreflex activity should be complemented by the classical pharmacological method. PMID:18667715

  2. Cardiovascular actions of L-cysteine and L-cysteine sulfinic acid in the nucleus tractus solitarius of the rat.

    PubMed

    Takemoto, Yumi

    2014-07-01

    The sulfur-containing excitatory amino acid (EAA) L-cysteine sulfinic acid (CSA), a neurotransmitter candidate, is endogenously synthesized from L-cysteine (Cys). Exogenous Cys administration into the brain produces cardiovascular effects; these effects likely occur via synaptic stimulation of central nervous system (CNS) neurons that regulate peripheral cardiovascular function. However, the cardiovascular responses produced by CNS Cys administration could result from CSA biosynthesized in synapse. The present study examined the role of CSA in Cys-induced cardiovascular responses within the nucleus tractus solitarius (NTS) of anesthetized rats. The NTS receives input from various visceral afferents that gate autonomic reflexes, including cardiovascular reflexes. Within the NTS, both Cys and CSA microinjections produced decrease responses in arterial blood pressure and heart rate that were similar to those produced by L-glutamate. Co-injection of the ionotropic EAA receptor antagonist kynurenic acid abolished Cys-, but not CSA-, induced cardiovascular responses. This finding suggests that only Cys-induced cardiovascular responses are mediated by kynurenate-sensitive receptors. This study provides the first demonstration that Cys- and CSA-induced cardiovascular responses occur via different mechanisms in the NTS of rats. Further, this study also indicates that Cys-induced cardiovascular responses do not occur via CSA. Thus, within the NTS, endogenous Cys and/or CSA might be involved in cardiovascular regulation.

  3. Socioeconomic and Psychosocial Gradients in Cardiovascular Pathogen Burden and Immune Response: The Multi-Ethnic Study of Atherosclerosis

    PubMed Central

    Aiello, Allison E.; Diez-Roux, Ana; Noone, Anne-Michelle; Ranjit, Nalini; Cushman, Mary; Tsai, Michael Y.; Szklo, Moyses

    2009-01-01

    Background The biologic mechanisms linking socioeconomic position and psychosocial factors to cardiovascular disease (CVD) are not well understood. Immune response to persistent pathogens may be one of these mechanisms. Methods We analyzed cross-sectional data from the Multi-Ethnic Study of Atherosclerosis (N=999) composed of adults age 45–84. Log-binomial regression and ordinal logistic regression models were used to examine associations of socioeconomic factors and psychosocial factors with pathogen burden and immune response among those infected. Pathogen burden was assessed based on seroprevalence of Helicobacter pylori, cytomegalovirus, herpes simplex virus-1, and Chlamydia pneumoniae and antibody levels were used to characterize high immune response to all four pathogens. Results Low education was a strong and significant independent predictor of higher pathogen burden after adjustment for covariates (adjusted odds ratio (OR) 95% confidence interval (CI) 1.37, 1.19–1.57). Among subjects seropositive for all four pathogens, low education and a higher level of chronic psychosocial stress showed a positive association with higher antibody response, although associations were no longer significant in models with all covariates included (OR = 1.64, 95%CI 0.82–3.31 for lowest vs. highest educational category and OR= 1.29, 95%CI 0.96–1.73 for a one level increase in chronic stress). Conclusion Pathogen burden and heightened immune response may represent a biological pathway by which low socioeconomic position and chronic stress are related to increased rates of cardiovascular disease. PMID:19150399

  4. Human cardiovascular and vestibular responses in long minutes and low +Gz loading by short arm centrifuge.

    PubMed

    Yajima, K; Miyamoto, A; Ito, M; Maru, R; Maeda, T; Sanada, E; Nakazato, T; Saiki, C; Yamaguchi, Y; Igarashi, M; Matsumoto, S

    1994-07-01

    1.4 G, 1.7 G, and 2.0 G of +Gz and 60 minutes centrifugation was adopted to 20 healthy male subjects using 1.8 m radius centrifuge equipped to Nihon University School of Medicine. G was applied from lower G, considering G training effect for the subjects. Effects on performance decline and side effects of such a short-arm centrifugation were especially observed in the experiments, because this size of centrifuge could be used in space station in future for a strong countermeasure of cardiovascular deconditioning, demineralization from bone, etc. G training effect was observed same as higher and rapid G acceleration in fighter pilot. Subjects suffered from many types of discomfort; such as sensation of heaviness of diaphragm, cold sweat, nausea, irritable feeling, arrhythmia, tachycardia, rapid decrease of blood pressure, which sometimes caused interruption of G load. As 2.0 G and 60 minutes centrifugation seemed very tough load to the subjects, there should be necessary some G suit or other countermeasure, if we apply a higher G and/or longer G duration. Performance decline due to the load commonly continued for 1 hour or so. Side effects were observed in relation to neuro-vestibular, cardio-vascular, and autonomic nervous system. PMID:11539528

  5. Postnatal development of the pattern of respiratory and cardiovascular response to systemic hypoxia in the piglet: the roles of adenosine.

    PubMed Central

    Elnazir, B; Marshall, J M; Kumar, P

    1996-01-01

    1. In 3-day-old and 3-week-old spontaneously breathing piglets anaesthetized with Saffan, we have studied ventilatory and cardiovascular responses evoked by 5 min periods of hypoxia (breathing 10 and 6% O2). 2. In 3-day-old piglets both 10 and 6% O2 evoked an increase followed by a secondary fall in ventilation, a gradual tachycardia and a renal vasoconstriction, with an increase in femoral blood flow that was attributable to femoral vasodilatation. Arterial blood pressure rose initially but fell towards control values by the 5th minute of hypoxia. 3. The stable adenosine analogue 2-chloroadenosine (2-CA; 30 mg kg(-1) i.v.) evoked bradycardia and renal vasoconstriction, but had no effect on femoral vasculature. These responses were blocked by the adenosine receptor antagonist 8-phenyltheophylline (8-PT; 8 mg kg(-1) i.v.). 8-PT also abolished the secondary fall in ventilation evoked by 10 and 6% O2 and the renal vasoconstriction evoked by 10% O2, but had no effect on the tachycardia, or on the femoral vascular response. 4. By contrast, in 3-week-old piglets both 10 and 6% O2 evoked a sustained increase in ventilation, tachycardia and a rise in arterial pressure with renal vasoconstriction, but no change in renal blood flow and substantial femoral vasodilatation with an increase in femoral blood flow. 2-CA evoked bradycardia and renal vasoconstriction, as in 3-day-old piglets, but also evoked pronounced femoral vasodilatation. 8-PT blocked these responses and the hypoxia-induced femoral vasodilatation, but had no significant effect on other components of the hypoxia-induced response. 5. We propose that there is postnatal development of the ventilatory and cardiovascular responses evoked by systemic hypoxia and of the role of locally released adenosine in these responses: at 3 days, adenosine released within the central nervous system and within the kidney is a major contributor to the secondary fall in ventilation and renal vasoconstriction respectively, whereas at 3

  6. Elimination of behavior of mental patients by response-produced extinction.

    PubMed

    HOLZ, W C; AZRIN, N H; AYLLON, T

    1963-07-01

    Mental hospital patients were conditioned to respond at a high rate. Then an attempt was made to eliminate the response by means of a mild punishment consisting of a period of timeout from reinforcement (response-produced extinction). When only one response was available for obtaining the reinforcement, the mild punishment was not effective in eliminating that response. When an alternative response was also made available for obtaining the reinforcement, the mild punishment was completely effective. It appears that even very mild punishment may be effective if the over-all frequency of reinforcement can be maintained by means of an alternative unpunished response.

  7. Community-responsive interventions to reduce cardiovascular risk in American Indians.

    PubMed

    Jobe, Jared B; Adams, Alexandra K; Henderson, Jeffrey A; Karanja, Njeri; Lee, Elisa T; Walters, Karina L

    2012-08-01

    American Indian and Alaska Native (AI/AN) populations bear a heavy burden of cardiovascular disease (CVD), and they have the highest rates of risk factors for CVD, such as cigarette smoking, obesity, and diabetes, of any U.S. population group. Yet, few randomized controlled trials have been launched to test potential preventive interventions in Indian Country. Five randomized controlled trials were initiated recently in AI/AN communities to test the effectiveness of interventions targeting adults and/or children to promote healthy behaviors that are known to impact biological CVD risk factors. This article provides a context for and an overview of these five trials. The high burden of CVD among AI/AN populations will worsen unless behaviors and lifestyles affecting CVD risk can be modified. These five trials, if successful, represent a starting point in addressing these significant health disparities. PMID:22983753

  8. Treatment with nebivolol combined with physical training promotes improvements in the cardiovascular responses of hypertensive rats.

    PubMed

    Goessler, Karla Fabiana; Martins-Pinge, Marli; Veronez da Cunha, Natalia; Karlen-Amarante, Marlusa; de Andrade, Fábio Goulart; Brum, Patricia Chakur; Polito, Marcos Doederlein

    2014-03-01

    The aim of this study was to determine whether exercise training combined with beta-blocker treatment promotes additional cardiovascular benefits compared with either intervention on its own. For this we used 76 Wistar rats distributed among different groups: normotensive sedentary (NS), normotensive trained (NT), normotensive sedentary treated with beta-blocker (NS_BB), normotensive trained treated with beta-blocker (NT_BB), hypertensive sedentary (HS), hypertensive trained (HT), hypertensive sedentary treated with a beta-blocker (HS_BB), and hypertensive trained rats treated with beta-blocker (HT_BB). Exercise training consisted of 4 weeks of swimming for 60 min a day, 5 days a week. Hypertension was induced with l-NAME (4 weeks), whereas the control rats received saline, and both the control and test rats received nebivolol. The animals underwent surgery to directly record their blood pressure. The HS group showed higher mean arterial pressure (MAP) (P = 0.000), systolic arterial pressure (P = 0.000), and diastolic arterial pressure (P = 0.000) compared with NS. MAP was higher in the HS compared with the HT (P = 0.002), HS_BB (P = 0.018), and HT_BB (P = 0.015) groups. Hearts from the HS group had a higher percentage of collagen compared with the NS and HS_BB groups. The HT_BB and HT groups only had a higher percentage of cardiac collagen by comparison with the HS_BB group. The HT_BB group showed higher levels of macrophages and neutrophils by comparison with the HT and HS_BB groups. Thus, treatment with a beta-blocker combined with physical training was associated with increased cardiovascular benefits over either intervention alone. PMID:24593788

  9. A Proposed Study Examining Individual Differences in Temporal Profiles of Cardiovascular Responses to Head Down Tilt During Fluid Loading

    NASA Technical Reports Server (NTRS)

    Cowings, Patricia; Toscano, William; Winther, Sean; Martinez, Jacqueline; Dominguez, Margaret

    2012-01-01

    Susceptibility of healthy astronauts to orthostatic hypotension and presyncope is exacerbated upon return from spaceflight. The effect of altered gravity during space flight and planetary transition on human cardiovascular function is of critical importance to maintenance of astronaut health and safety. Hypovolemia, reduced plasma volume, is suspected to play an important role in cardiovascular deconditioning following exposure to spaceflight, which may lead to increased peripheral resistance, attenuated arterial baroreflex, and changes in cardiac function. A promising countermeasure for post-flight orthostatic intolerance is fluid loading used to restore lost plasma volume by giving crew salt tablets and water prior to re-entry. The main purpose of the proposed study is to define the temporal profile of cardiac responses to simulated 0-G conditions before and following a fluid loading countermeasure. 8 men and 8 women will be tested during 4 hour exposures at 6o head down tilt (HDT). Each subject will be given two exposures to HDT on separate days, one with and one without fluid loading (one liter of 0.9% saline solution). Stand tests (orthostatic stress) will be done before and after each HDT. Cardiac measures will be obtained with both impedance cardiography and echo ultrasound

  10. Effects of arginine vasotocin (AVT) on the behavioral, cardiovascular, and corticosterone responses of starlings (Sturnus vulgaris) to crowding.

    PubMed

    Nephew, Benjamin C; Aaron, Robert S; Romero, L Michael

    2005-03-01

    Previous studies in European starlings have concluded that conspecific crowding can be a significant stressor that is capable of simultaneously altering behavior, heart rate, and corticosterone (CORT) concentrations. It was hypothesized that the peptide hormone arginine vasotocin (AVT) has a role in the regulation of these three types of responses to crowding. Four male and four female resident starlings were submitted to nine combinations of 3 crowding treatments (0, 1, or 5 intruder starlings) and 3 subcutaneous injections (1, 4 microg AVT, and saline control). Resident starlings were given a treatment injection, their heart rate and behavior were monitored for 30 min, 0, 1, or 5 intruder Starlings were allowed to enter the residents cage, and HR and behavior were monitored for another 30 min. Blood samples were taken before and after all treatments to assess CORT concentrations. Exogenous AVT decreased the frequency of maintenance behaviors (feeding, drinking, preening, and beak wiping), as well as activity in resident starlings. Although aggressive behaviors upright posture, head feather expansion, and pecking) increased during crowding, these increases were significantly attenuated by AVT. Heart rate was significantly lower during these behavioral effects, and the CORT data indicate that the cardiovascular and behavioral effects are not dependent on significant increases in CORT. These data support the hypothesis that AVT's attenuation of general behavior and crowding induced aggression are modulated by a cardiovascular mechanism. PMID:15708756

  11. Autonomic Cardiovascular Responses in Acclimatized Lowlanders on Prolonged Stay at High Altitude: A Longitudinal Follow Up Study

    PubMed Central

    Dhar, Priyanka; Sharma, Vijay K.; Hota, Kalpana B.; Das, Saroj K.; Hota, Sunil K.; Srivastava, Ravi B.; Singh, Shashi B.

    2014-01-01

    Acute exposure to hypobaric hypoxia at high altitude is reported to cause sympathetic dominance that may contribute to the pathophysiology of high altitude illnesses. The effect of prolonged stay at high altitude on autonomic functions, however, remains to be explored. Thus, the present study aimed at investigating the effect of high altitude on autonomic neural control of cardiovascular responses by monitoring heart rate variability (HRV) during chronic hypobaric hypoxia. Baseline electrocardiography (ECG) data was acquired from the volunteers at mean sea level (MSL) (<250 m) in Rajasthan. Following induction of the study population to high altitude (4500–4800 m) in Ladakh region, ECG data was acquired from the volunteers after 6 months (ALL 6) and 18 months of induction (ALL 18). Out of 159 volunteers who underwent complete investigation during acquisition of baseline data, we have only included the data of 104 volunteers who constantly stayed at high altitude for 18 months to complete the final follow up after 18 months. HRV parameters, physiological indices and biochemical changes in serum were investigated. Our results show sympathetic hyperactivation along with compromise in parasympathetic activity in ALL 6 and ALL 18 when compared to baseline data. Reduction of sympathetic activity and increased parasympathetic response was however observed in ALL 18 when compared to ALL 6. Our findings suggest that autonomic response is regulated by two distinct mechanisms in the ALL 6 and ALL 18. While the autonomic alterations in the ALL 6 group could be attributed to increased sympathetic activity resulting from increased plasma catecholamine concentration, the sympathetic activity in ALL 18 group is associated with increased concentration of serum coronary risk factors and elevated homocysteine. These findings have important clinical implications in assessment of susceptibility to cardio-vascular risks in acclimatized lowlanders staying for prolonged duration at high

  12. Repeated Administration of a Mutant Cocaine Esterase: Effects on Plasma Cocaine Levels, Cocaine-Induced Cardiovascular Activity, and Immune Responses in Rhesus Monkeys

    PubMed Central

    Collins, Gregory T.; Brim, Remy L.; Noon, Kathleen R.; Narasimhan, Diwahar; Lukacs, Nicholas W.; Sunahara, Roger K.; Woods, James H.

    2012-01-01

    Previous studies have demonstrated the capacity of a long-acting mutant form of a naturally occurring bacterial double mutant cocaine esterase (DM CocE) to antagonize the reinforcing, discriminative, convulsant, and lethal effects of cocaine in rodents and reverse the increases in mean arterial pressure (MAP) and heart rate (HR) produced by cocaine in rhesus monkeys. This study was aimed at characterizing the immunologic responses to repeated dosing with DM CocE and determining whether the development of anti-CocE antibodies altered the capacity of DM CocE to reduce plasma cocaine levels and ameliorate the cardiovascular effects of cocaine in rhesus monkeys. Under control conditions, intravenous administration of cocaine (3 mg/kg) resulted in a rapid increase in the plasma concentration of cocaine (n = 2) and long-lasting increases in MAP and HR (n = 3). Administration of DM CocE (0.32 mg/kg i.v.) 10 min after cocaine resulted in a rapid hydrolysis of cocaine with plasma levels below detection limits within 5 to 8 min. Elevations in MAP and HR were significantly reduced within 25 and 50 min of DM CocE administration, respectively. Although slight (10-fold) increases in anti-CocE antibodies were observed after the fourth administration of DM CocE, these antibodies did not alter the capacity of DM CocE to reduce plasma cocaine levels or ameliorate cocaine's cardiovascular effects. Anti-CocE titers were transient and generally dissipated within 8 weeks. Together, these results suggest that highly efficient cocaine esterases, such as DM CocE, may provide a novel and effective therapeutic for the treatment of acute cocaine intoxication in humans. PMID:22518021

  13. Repeated administration of a mutant cocaine esterase: effects on plasma cocaine levels, cocaine-induced cardiovascular activity, and immune responses in rhesus monkeys.

    PubMed

    Collins, Gregory T; Brim, Remy L; Noon, Kathleen R; Narasimhan, Diwahar; Lukacs, Nicholas W; Sunahara, Roger K; Woods, James H; Ko, Mei-Chuan

    2012-07-01

    Previous studies have demonstrated the capacity of a long-acting mutant form of a naturally occurring bacterial double mutant cocaine esterase (DM CocE) to antagonize the reinforcing, discriminative, convulsant, and lethal effects of cocaine in rodents and reverse the increases in mean arterial pressure (MAP) and heart rate (HR) produced by cocaine in rhesus monkeys. This study was aimed at characterizing the immunologic responses to repeated dosing with DM CocE and determining whether the development of anti-CocE antibodies altered the capacity of DM CocE to reduce plasma cocaine levels and ameliorate the cardiovascular effects of cocaine in rhesus monkeys. Under control conditions, intravenous administration of cocaine (3 mg/kg) resulted in a rapid increase in the plasma concentration of cocaine (n = 2) and long-lasting increases in MAP and HR (n = 3). Administration of DM CocE (0.32 mg/kg i.v.) 10 min after cocaine resulted in a rapid hydrolysis of cocaine with plasma levels below detection limits within 5 to 8 min. Elevations in MAP and HR were significantly reduced within 25 and 50 min of DM CocE administration, respectively. Although slight (10-fold) increases in anti-CocE antibodies were observed after the fourth administration of DM CocE, these antibodies did not alter the capacity of DM CocE to reduce plasma cocaine levels or ameliorate cocaine's cardiovascular effects. Anti-CocE titers were transient and generally dissipated within 8 weeks. Together, these results suggest that highly efficient cocaine esterases, such as DM CocE, may provide a novel and effective therapeutic for the treatment of acute cocaine intoxication in humans. PMID:22518021

  14. Does exercise training during pregnancy influence fetal cardiovascular responses to an exercise stimulus? Insights from a randomised, controlled trial.

    PubMed

    Barakat, R; Ruiz, J R; Rodríguez-Romo, G; Montejo-Rodríguez, R; Lucia, A

    2010-08-01

    In this study, the effects of maternal physical activity level on several fetal haemodynamic parameters such as pulsatility index of the fetal middle cerebral and umbilical arteries and cerebral-to-fetal ratio, as well as on fetal heart rate responses to one bout of moderate exercise (20 min cycle-ergometry at approximately 60% of age-predicted maximum heart rate) during the third pregnancy trimester were assessed. 26 Sedentary and 26 physically active gravidae aged 29 (3) and 30 (2) years, respectively, were studied. Maternal exercise did not have a deleterious effect on fetal haemodynamics (particularly, cerebral-to-fetal ratio remained within normal limits with exercise). Overall, maternal training status did not influence the fetal cardiovascular variables studied.

  15. Acute Cardiovascular Response during Resistance Exercise with Whole-body Vibration in Sedentary Subjects: A Randomized Cross-over Trial.

    PubMed

    Dias, Thaisa; Polito, Marcos

    2015-01-01

    This study aimed to compare the acute cardiovascular responses during and after resistance exercise with and without whole-body vibration. Nineteen sedentary adults randomly performed one session of isometric squats without vibration and the same exercise with vibration. Systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), stroke volume (SV), cardiac output (CO) and systemic vascular resistance (SVR) were measured. SBP, DBP and HR were also measured for 20 min after the sessions. The exercise with vibration demonstrated significant values ​​(P < 0.05) for SBP (second to sixth sets), DBP (third to sixth sets) and SVR (second to sixth sets) compared with the exercise without vibration. After the sessions, the values ​​of SBP for both exercises were significantly lower than the respective resting values; with no difference between the sessions. In conclusion, exercise with vibration caused increases in SBP, DBP and SVR compared with exercise with no vibration in sedentary adults.

  16. Characterization of fluid physics effects on cardiovascular response to microgravity (G-572)

    NASA Technical Reports Server (NTRS)

    Pantalos, George M.; Sharp, M. Keith; Woodruff, Stewart J.; Lorange, Richard D.; Bennett, Thomas E.; Sojka, Jan J.; Lemon, Mark W.

    1993-01-01

    The recognition and understanding of cardiovascular adaptation to spaceflight has experienced substantial advancement in the last several years. In-flight echocardiographic measurements of astronaut cardiac function on the Space Shuttle have documented a 15 percent reduction in both left ventricular volume index and stroke volume with a compensatory increase in heart rate to maintain cardiac output. To date, the reduced cardiac size and stroke volume have been presumed to be the consequence of the reduction in circulating fluid volume following diuresis and other physiological processes to reduce blood volume within a few days after orbital insertion. However, no specific mechanism for the reduced stroke volume has been elucidated. The following investigation proposes the use of a hydraulic model of the cardiovascular system to examine the possibility that the observed reduction in stroke volume may, in part, be related to fluid physics effects on heart function. The automated model is being prepared to fly as a GAS payload. The experimental apparatus consists of a pneumatically actuated, elliptical artificial ventricle connected to a closed-loop, hydraulic circuit with compliance and resistance elements to create physiologic pressure and flow conditions. The ventricle is instrumented with high-fidelity, acceleration-insensitive, catheter-tip pressure transducers (Millar Instruments) in the apex and base to determine the instantaneous ventricular pressures and (delta)P(sub LV) across the left ventricle (LVP(sub apex)-LVP(sub base). The ventricle is also instrumented with a flow probe and pressure transducers immediately upstream of the inflow valve and downstream of the outflow valve. The experiment will be microprocessor controlled with analog signals stored on the FM data tape recorder. By varying the circulating fluid volume, ventricular function can be determined for varying preload pressures with fixed afterload pressure. Pilot experiments on board the NASA KC

  17. Studies on the cardiovascular effects produced by the spinal action of two substance P analogues in the rat: evidence for a central catecholaminergic mechanism.

    PubMed

    Couture, R; Gupta, A; Kérouac, R; Regoli, D

    1987-03-31

    The effects of two substance P (SP) analogues, [D-Trp7,9,10]SP (ana1) and [D-Pro4,Lys6,D-Trp7,9,10,Phe11]SP-(4-11) (ana2) on mean arterial pressure (MAP) and heart rate (HR) were measured following intrathecal administration at one of three spinal cord levels in rats anaesthetized with sodium pentobarbital. Following an initial increase, a profound and long-lasting fall in MAP and HR occurred when 6.5 nmol of either ana1 or ana2 was injected at T1-T3 or T8-T10. Only transient changes in MAP and a slight increase in HR was observed after injection of either peptide at L2-L4. The profound and long-lasting hypotension and bradycardia induced by ana1 were not significantly altered after intravenous injection of hexamethonium, phentolamine, propranolol, atropine, diphenhydramine, cimetidine, methysergide, naloxone or morphine. However, the biphasic effect of ana1 on MAP was prevented by the intrathecal administration of prazosin and yohimbine, suggesting that a central catecholaminergic mechanism including alpha 1- and alpha 2-adrenergic receptors is involved. The latter treatment did not prevent the tachycardia which occurred when the bradycardia was blocked, indicating that different mechanisms mediate the spinal action of ana1 on MAP and HR. Finally, cervical transection of the spinal cord eliminated the profound and long-lasting depressor effect of ana2, suggesting that a supraspinal mechanism is involved in this cardiovascular response.

  18. The relationship of hostility, negative affect and ethnicity to cardiovascular responses: an ambulatory study in Singapore.

    PubMed

    Enkelmann, Hwee Chong; Bishop, George D; Tong, Eddie M W; Diong, Siew Maan; Why, Yong Peng; Khader, Majeed; Ang, Jansen

    2005-05-01

    This study tested the hypotheses that ambulatory heart rate and blood pressure would be higher for individuals high but not low in hostility when they experienced negative affect or social stress and that this interaction would be stronger for Indians compared with other Singapore ethnic groups. Ambulatory blood pressure monitoring was done on 108 male Singapore patrol officers as they went about their daily duties. After each BP measurement participants completed a computerized questionnaire including items on emotional experience. Individuals high in hostility showed higher systolic blood pressure when reporting negative affect whereas this was not true for those low in hostility. Ethnic differences were obtained such that Indians showed an increase in mean arterial pressure when angered whereas MAP was negatively related to anger for Malays and unrelated for Chinese. Also a three-way interaction between ethnicity, hostility, and social stress indicated that hostility and social stress interacted in their effects on DBP for Indian participants but not for Chinese or Malays. Finally, a three-way interaction was obtained between ethnicity, hostility and negative affect for heart rate in which heart rate increased with increasing levels of negative affect for Chinese high in hostility and Malays low in hostility but decreased with increasing negative affect for all other participants. These data are consistent with higher CHD rates among individuals high in hostility and also provide additional evidence on ethnic differences in cardiovascular reactivity in Singapore.

  19. Involvement of the histaminergic system in renal sympathetic and cardiovascular responses to leptin and ghrelin.

    PubMed

    Tanida, Mamoru; Kaneko, Hidekazu; Shen, Jiao; Nagai, Katsuya

    2007-02-01

    Previous studies have demonstrated that histamine affects blood pressure (BP) in anesthetized rats. Here, we examined the effects of lateral cerebral ventricular (LCV) injection of various doses of histamine on renal sympathetic nerve activity (RSNA) and BP in anesthetized rats. LCV injection of a low dose of histamine (0.0001nmol) suppressed RSNA and BP. Conversely, a high dose of histamine (100nmol) elevated both RSNA and BP. Moreover, inhibiting effects of a low dose of histamine were eliminated by LCV pre-injection of thioperamide, an antagonist of histaminergic H3-receptor, and accelerating effects of a high dose of histamine were abolished by LCV pre-injection of diphenhydramine, an antagonist of histaminergic H1-receptor. Thus, these evidences suggest that central histamine affects RSNA and BP via histaminergic receptors. In addition, we examined a role for histaminergic system in cardiovascular modulators such as leptin and ghrelin. The LCV pre-injection of thioperamide clearly blocked suppressing effects of ghrelin on RSNA and BP. The LCV pre-injection of diphenhydramine also blocked elevating effects of leptin. Therefore, these results suggest that leptin and ghrelin might affect RSNA and BP by mediating central histaminegic H1- and H3-receptors, respectively.

  20. Hemoglobin βCys93 is essential for cardiovascular function and integrated response to hypoxia.

    PubMed

    Zhang, Rongli; Hess, Douglas T; Qian, Zhaoxia; Hausladen, Alfred; Fonseca, Fabio; Chaube, Ruchi; Reynolds, James D; Stamler, Jonathan S

    2015-05-19

    Oxygen delivery by Hb is essential for vertebrate life. Three amino acids in Hb are strictly conserved in all mammals and birds, but only two of those, a His and a Phe that stabilize the heme moiety, are needed to carry O2. The third conserved residue is a Cys within the β-chain (βCys93) that has been assigned a role in S-nitrosothiol (SNO)-based hypoxic vasodilation by RBCs. Under this model, the delivery of SNO-based NO bioactivity by Hb redefines the respiratory cycle as a triune system (NO/O2/CO2). However, the physiological ramifications of RBC-mediated vasodilation are unknown, and the apparently essential nature of βCys93 remains unclear. Here we report that mice with a βCys93Ala mutation are deficient in hypoxic vasodilation that governs blood flow autoregulation, the classic physiological mechanism that controls tissue oxygenation but whose molecular basis has been a longstanding mystery. Peripheral blood flow and tissue oxygenation are decreased at baseline in mutant animals and decline excessively during hypoxia. In addition, βCys93Ala mutation results in myocardial ischemia under basal normoxic conditions and in acute cardiac decompensation and enhanced mortality during transient hypoxia. Fetal viability is diminished also. Thus, βCys93-derived SNO bioactivity is essential for tissue oxygenation by RBCs within the respiratory cycle that is required for both normal cardiovascular function and circulatory adaptation to hypoxia.

  1. Response-produced timeouts under a progressive-ratio schedule with a punished reset option

    NASA Technical Reports Server (NTRS)

    Dardano, J. F.

    1974-01-01

    An attempt is made to extend the generality of timeouts from positive reinforcement to more complex performances. Pigeons were provided with three continuously available options. Responses on one key resulted in food reinforcement under a progressive-ratio schedule, which requires a larger number of responses for successive reinforcements; responses on a second key, which were shocked, reset the progressive-ratio schedule to its first step; and responses on a third key produced a 3-min timeout. Some of these conditions have been studied previously (Dardano, 1968, 1973; Findley, 1958). Questions of general interest included the frequency and stability of response-produced timeouts, changes in the properties of the progressive-ratio performance resulting from the occurrence of timeouts, and the similarity of the relationships between timeouts and the reinforced behavior to relationships found under simpler conditions of reinforcement.

  2. Daytime Napping and the Risk of Cardiovascular Disease and All-Cause Mortality: A Prospective Study and Dose-Response Meta-Analysis

    PubMed Central

    Yamada, Tomohide; Hara, Kazuo; Shojima, Nobuhiro; Yamauchi, Toshimasa; Kadowaki, Takashi

    2015-01-01

    Study Objectives: To summarize evidence about the association between daytime napping and the risk of cardiovascular disease and all-cause mortality, and to quantify the potential dose-response relation. Design: Meta-analysis of prospective cohort studies. Methods and Results: Electronic databases were searched for articles published up to December 2014 using the terms nap, cardiovascular disease, and all-cause mortality. We selected well-adjusted prospective cohort studies reporting risk estimates for cardiovascular disease and all-cause mortality related to napping. Eleven prospective cohort studies were identified with 151,588 participants (1,625,012 person-years) and a mean follow-up period of 11 years (60% women, 5,276 cardiovascular events, and 18,966 all-cause deaths). Pooled analysis showed that a long daytime nap (≥ 60 min/day) was associated with a higher risk of cardiovascular disease (rate ratio [RR]: 1.82 [1.22–2.71], P = 0.003, I2 = 37%) compared with not napping. All-cause mortality was associated with napping for ≥ 60 min/day (RR: 1.27 [1.11–1.45], P < 0.001, I2 = 0%) compared with not napping. In contrast, napping for < 60 min/day was not associated with cardiovascular disease (P = 0.98) or all-cause mortality (P = 0.08). Meta-analysis demonstrated a significant J-curve dose-response relation between nap time and cardiovascular disease (P for nonlinearity = 0.01). The RR initially decreased from 0 to 30 min/day. Then it increased slightly until about 45 min/day, followed by a sharp increase at longer nap times. There was also a positive linear relation between nap time and all-cause mortality (P for non-linearity = 0.97). Conclusions: Nap time and cardiovascular disease may be associated via a J-curve relation. Further studies are needed to confirm the efficacy of a short nap. Citation: Yamada T, Hara K, Shojima N, Yamauchi T, Kadowaki T. Daytime napping and the risk of cardiovascular disease and all-cause mortality: a prospective study and

  3. Association of variants in NEDD4L with blood pressure response and adverse cardiovascular outcomes in hypertensive patients treated with thiazide diuretics

    PubMed Central

    McDonough, Caitrin W.; Burbage, Sarah E.; Duarte, Julio D.; Gong, Yan; Langaee, Taimour Y.; Turner, Stephen T.; Gums, John G.; Chapman, Arlene B.; Bailey, Kent R.; Beitelshees, Amber L.; Boerwinkle, Eric; Pepine, Carl J.; Cooper-DeHoff, Rhonda M.; Johnson, Julie A.

    2013-01-01

    Objective Single-nucleotide polymorphisms (SNPs) in NEDD4L may influence the ability of the NEDD4L protein to reduce epithelial sodium channel expression. A variant in NEDD4L, rs4149601, was associated with antihypertensive response and cardiovascular outcomes during treatment with thiazide diuretics and β-blockers in a Swedish population. We sought to further evaluate associations between NEDD4L polymorphisms, blood pressure response and cardiovascular outcomes with thiazide diuretics and β-blockers. Methods Four SNPs, rs4149601, rs292449, rs1008899 and rs75982813, were genotyped in 767 patients from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) clinical trial and association was assessed with blood pressure response to hydrochlorothiazide and atenolol. One SNP, rs4149601, was also genotyped in 1345 patients from the International Verapmil SR Trandolapril Study (INVEST), and association was examined with adverse cardiovascular outcomes relative to hydrochlorothiazide treatment. Results Significant associations or trends were found between rs4149601, rs292449, rs75982813 and rs1008899 and decreases in blood pressure in whites on hydrochlorothiazide, and a significant association was observed with increasing copies of the GC rs4149601-rs292449 haplotype and greater blood pressure response to hydrochlorothiazide in whites (P = 0.0006 and 0.006, SBP and DBP, respectively). Significant associations were also seen with rs4149601 and an increased risk for adverse cardiovascular outcomes in whites not treated with hydrochlorothiazide [P = 0.022, odds ratio (95% confidence interval) = 10.65 (1.18–96.25)]. Conclusion NEDD4L rs4149601, rs292449 and rs75982813 may be predictors for blood pressure response to hydrochlorothiazide in whites, and NEDD4L rs4149601 may be a predictor for adverse cardiovascular outcomes in whites not treated with hydrochlorothiazide. PMID:23353631

  4. [Resting heart rate and cardiovascular disease].

    PubMed

    Brito Díaz, Buenaventura; Alemán Sánchez, José Juan; Cabrera de León, Antonio

    2014-07-01

    Heart rate reflects autonomic nervous system activity. Numerous studies have demonstrated that an increased heart rate at rest is associated with cardiovascular morbidity and mortality as an independent risk factor. It has been shown a link between cardiac autonomic balance and inflammation. Thus, an elevated heart rate produces a micro-inflammatory response and is involved in the pathogenesis of endothelial dysfunction. In turn, decrease in heart rate produces benefits in congestive heart failure, myocardial infarction, atrial fibrillation, obesity, hyperinsulinemia, insulin resistance, and atherosclerosis. Alteration of other heart rate-related parameters, such as their variability and recovery after exercise, is associated with risk of cardiovascular events. Drugs reducing the heart rate (beta-blockers, calcium antagonists and inhibitors of If channels) have the potential to reduce cardiovascular events. Although not recommended in healthy subjects, interventions for reducing heart rate constitute a reasonable therapeutic goal in certain pathologies.

  5. A dose-response of consuming high fructose corn syrup-sweetened beverages on lipid/lipoprotein risk factors for cardiovascular disease in young adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    National Health and Nutrition Examination Survey data show increased risk of cardiovascular disease (CVD) mortality with increased intake of added sugar across quintiles. Objective: To determine the dose response effects of consuming beverages sweetened with high fructose corn syrup (HFCS) at zero, ...

  6. Cardiovascular responses to catecholamines at 12 degrees C in the American bullfrog (Rana catesbeiana).

    PubMed

    Herman, C A; Robleto, D O; Mata, P L; Heller, R S

    1986-10-01

    The effects of epinephrine, norepinephrine, phenylephrine, and isoproterenol on blood pressure and heart rate were studied in cannulated American bullfrogs, Rana catesbeiana. The bullfrogs were chronically cannulated with a T cannula in the right sciatic artery. In warm-acclimated (22 degrees C) bullfrogs, preinjection mean systemic arterial pressure (SAP) prior to experimental treatment was 13.1 +/- 0.7 mm Hg. Preinjection heart rate was 34.8 +/- 1.8 beats per minute. These parameters were lower in cold-acclimated (12 degrees C) bullfrogs. Cold-acclimated animals had mean SAP values of 8.2 +/- 0.3 mm Hg, and heart rate was 11.1 +/- 1.1 beats per minute. Epinephrine, norepinephrine, and phenylephrine increased blood pressure to an equivalent degree in warm- and cold-acclimated animals. Dose-related decreases in heart rate in response to these catecholamines were observed in warm- but not in cold-acclimated bullfrogs. Warm-acclimated animals were more responsive to isoproterenol from 0.03 micrograms/kg body weight (bw) to 10 micrograms/kg bw than were cold-acclimated animals. The response to isoproterenol was effectively blocked by propranolol (5 mg/kg bw) in both warm- and cold-acclimated animals. Propranolol alone decreased mean SAP in both warm- and cold-acclimated animals, suggesting blockade of endogenous sympathetic activity. Beta receptor response thus appears diminished, but not absent at 12 degrees C. However, the alpha receptors responsible for elevation of blood pressure equally responsive at 12 degrees and 22 degrees C.

  7. Role of aortic input impedance in the decreased cardiovascular response to exercise with aging in dogs.

    PubMed Central

    Yin, F C; Weisfeldt, M L; Milnor, W R

    1981-01-01

    The diminished cardiac output response to exercise with advancing age may be attributable to intrinsic inability of the old ventricle to respond appropriately and/or to an additional loading imposed upon the ventricle by the aged vascular system. The steady (resistance) and pulsatile (characteristic impedance) load components together comprise the vascular load faced by the ejecting ventricle. To study the effect of exercise on both vascular components of load, the aortic input impedance was measured in chronically instrumented young and old beagle dogs during graded treadmill exercise before and after beta blockade. Ascending aortic flow was measured by a cuff electromagnetic flow probe, and pressure was measured by a high-fidelity semiconductor transducer. At low levels of exercise the old animals demonstrated a striking 20% increase in characteristic impedance and a 28% decrease in peripheral resistance with no increase in stroke volume. This vascular loading and limitation in stroke volume persisted across the higher exercise levels. In contrast, the young group demonstrated no increase in characteristic impedence, a progressive decrease in peripheral resistance, and a progressive increase in stroke volume across the same exercise levels. These age differences in vascular response and ventricular output were abolished by beta blockade. The groups did not demonstrate a difference in heart rate response, but the young had a greater increase in external left ventricular power than the old across exercise. These data demonstrated a profound difference in the response of young and old vasculature to exercise. At low and intermediate exercise levels the pulsatile vascular load appeared to be a major factor in the limitation of stroke volume in old dogs. At high levels of exercise, the limited exercise response in the old dog may be caused in part by a diminished inotropic responsiveness as well as by the vascular loading. PMID:7251864

  8. Coffee consumption and mortality from all causes, cardiovascular disease, and cancer: a dose-response meta-analysis.

    PubMed

    Crippa, Alessio; Discacciati, Andrea; Larsson, Susanna C; Wolk, Alicja; Orsini, Nicola

    2014-10-15

    Several studies have analyzed the relationship between coffee consumption and mortality, but the shape of the association remains unclear. We conducted a dose-response meta-analysis of prospective studies to examine the dose-response associations between coffee consumption and mortality from all causes, cardiovascular disease (CVD), and all cancers. Pertinent studies, published between 1966 and 2013, were identified by searching PubMed and by reviewing the reference lists of the selected articles. Prospective studies in which investigators reported relative risks of mortality from all causes, CVD, and all cancers for 3 or more categories of coffee consumption were eligible. Results from individual studies were pooled using a random-effects model. Twenty-one prospective studies, with 121,915 deaths and 997,464 participants, met the inclusion criteria. There was strong evidence of nonlinear associations between coffee consumption and mortality for all causes and CVD (P for nonlinearity < 0.001). The largest risk reductions were observed for 4 cups/day for all-cause mortality (16%, 95% confidence interval: 13, 18) and 3 cups/day for CVD mortality (21%, 95% confidence interval: 16, 26). Coffee consumption was not associated with cancer mortality. Findings from this meta-analysis indicate that coffee consumption is inversely associated with all-cause and CVD mortality.

  9. Cardiovascular and metabolic responses of trained and untrained middle-aged men to a graded treadmill walking test.

    PubMed Central

    Williams, D. H.; Williams, C.

    1983-01-01

    A treadmill walking test was developed in order to provide a suitable method of assessing the fitness levels of sedentary middle-aged men (mean age, 44.3 yrs) at submaximal intensity. The incremental stages of the test enabled subjects to terminate the workload whenever undue discomfort was experienced. The test procedure was used in a preliminary experiment to compare the cardiovascular and metabolic responses of trained and untrained middle-aged men to exercise. Heart rate responses to the test were significantly higher (p less than 0.01) in the untrained, compared with the trained, men as were the post-exercise blood lactic acid concentrations (p less than 0.01), Respiratory Exchange Ratios (p less than 0.01), Ventilatory Equivalents (p less than 0.05) and Rate of Perceived Exertion (p less than 0.01). However, there were no differences in the oxygen cost of walking between the two groups. Images p110-a p110-b PMID:6883018

  10. Mind over Matter: Reappraising Arousal Improves Cardiovascular and Cognitive Responses to Stress

    ERIC Educational Resources Information Center

    Jamieson, Jeremy P.; Nock, Matthew K.; Mendes, Wendy Berry

    2012-01-01

    Researchers have theorized that changing the way we think about our bodily responses can improve our physiological and cognitive reactions to stressful events. However, the underlying processes through which mental states improve downstream outcomes are not well understood. To this end, we examined whether reappraising stress-induced arousal could…

  11. Cardiovascular and Affective Responses to Social Stress in Adolescents with Internalizing and Externalizing Problems

    ERIC Educational Resources Information Center

    Hastings, Paul D.; Zahn-Waxler, Carolyn; Usher, Barbara A.

    2007-01-01

    Behavioral responses to stress and challenge are based in emotional and physiological arousal reactions. Adolescents with maladaptive or problematic behavior patterns, such as internalizing or externalizing problems, are likely to show atypical emotional and physiological reactions to stress. Relations between problems and reactions to stress were…

  12. Metabolic and Cardiovascular Responses during Aquatic Exercise in Water at Different Temperatures in Older Adults

    ERIC Educational Resources Information Center

    Bergamin, Marco; Ermolao, Andrea; Matten, Sonia; Sieverdes, John C.; Zaccaria, Marco

    2015-01-01

    Purpose: The aim of this study was to investigate the physiological responses during upper-body aquatic exercises in older adults with different pool temperatures. Method: Eleven older men (aged 65 years and older) underwent 2 identical aquatic exercise sessions that consisted of 3 upper-body exercises using progressive intensities (30, 35, and 40…

  13. Thermoregulatory, Cardiovascular, and Metabolic Responses to Mild Caloric Restriction in the Brown Norway Rat

    EPA Science Inventory

    Caloric restriction (CR) has been demonstrated to prolong the life span of a variety of species. CR-induced reduction in core temperature (Tc) is considered a key mechanism responsible for prolonging life span in rodents; however, little is known on the regulation of CR-induced h...

  14. Cardiovascular responses induced by Catalase Inhibitior into the Fourth Cerebral Ventricle is changed in Wistar rats exposed to sidestream cigarette smoke

    PubMed Central

    Valenti, Vitor E.; de Abreu, Luiz Carlos; Fonseca, Fernando L. A.; Figueiredo, Jose-Luiz; Adami, Fernando; Ferreira, Celso

    2013-01-01

    Objectives This experimental study aimed to evaluate the effects of central catalase inhibition on cardiovascular responses in rats exposed to sidestream cigarette smoke (SSCS) for 3 weeks. Methodology A total of 20 males Wistar rats (320–370g) were implanted with a stainless steel guide cannula into the fourth cerebral ventricle (4thV). Femoral artery and vein were cannulated for mean arterial pressure (MAP) and heart rate (HR) measurement and drug infusion, respectively. Rats were exposed to SSCS for three weeks, 180 minutes per day, 5 days/week [carbon monoxide (CO): 100–300 ppm)]. Baroreflex was tested with one pressor dose of phenylephrine (PHE, 8 μg/kg, bolus) and one depressor dose of sodium nitroprusside (SNP, 50 μg/kg, bolus). Cardiovascular responses were evaluated before and 15 minutes after 3-amino-1, 2, 4-triazole (ATZ, catalase inhibitor, 0.001g/100μL) injection into the 4th V. Results Vehicle treatment into the 4th V did not change cardiovascular responses. Central catalase inhibition increased tachycardic peak, attenuated bradycardic peak and reduced HR range at 15 minutes, increased MAP at 5, 15 and 30 min and increased HR at 5 and 15 min. In rats exposed to SSCS, central ATZ increased basal MAP after 5 min and increased HR at 5, 15 and 30 minutes, respectively, and attenuated bradycardic peak at 15 minutes. Conclusion This study suggests that brain oxidative stress caused by SSCS influences autonomic regulation of the cardiovascular system. PMID:24421748

  15. Cardiovascular responses to a laboratory stressor in women: Assessing the role of body awareness

    PubMed Central

    Lustyk, M. Kathleen B.; Douglas, Haley A.C.; Bentley, Jacob A.; Gerrish, Winslow G.

    2016-01-01

    Body awareness (BA) is characterised by a general tendency towards awareness and recognition of normal, non-emotive bodily processes and physical sensations. BA considers one’s sensitivity towards and belief in how well they can sense, predict, and describe their bodily functions and sensations. This study investigated the role of BA in haemodynamic and anxiety responses to a laboratory stressor. Women (n = 40) completed assessments of BA and state/trait anxiety. Women with low BA displayed higher blood pressure (BP) and heart rate (HR) reactivity in response to the stressor than women with high BA. Delayed HR recovery poststressor was observed in women with low BA. BA was a significant predictor of haemodynamic reactivity over and above trait anxiety. BA effects on state anxiety were not observed. Thus, greater BA is associated with less haemodynamic stress reactivity in women lending further support for the development of BA interventions aimed at stress reduction.

  16. Central and peripheral cardiovascular responses to electrically induced and voluntary leg exercise

    NASA Technical Reports Server (NTRS)

    Saltin, B.; Strange, S.; Bangsbo, J.; Kim, C. K.; Duvoisin, M.; Hargens, A.; Gollnick, P. D.

    1990-01-01

    With long missions in space countermeasures have to be used to secure safe operations in space and a safe return to Earth. Exercises of various forms have been used, but the question has arisen whether electrically induced contractions of muscle especially sensitive to weightlessness and crucial for man's performance would aid in maintaining their optimal function. The physiological responses both to short term and prolonged dynamic exercise performed either voluntarily or induced by electrical stimulation were considered. The local and systemic circulatory responses were similar for the voluntary and electrically induced contractions. The metabolic response was slightly more pronounced with electrical stimulation. This could be a reflection of not only slow twitch (type 1) but also fast twitch (type 2) fibers being recruited when the contractions were induced electrically. Intramuscular pressure recordings indicated that the dominant fraction of the muscle group was engaged regardless of mode of activation. Some 70 percent of the short term peak voluntary exercise capacity could be attained with electrical stimulation. Thus, electrically induced contractions of specific muscle groups should indeed be considered as an efficient countermeasure.

  17. Haemodynamic modeling of the cardiovascular system using mock circulation loops to test cardiovascular devices.

    PubMed

    Timms, Daniel L; Gregory, Shaun D; Stevens, Michael C; Fraser, John F

    2011-01-01

    Comprehensive testing and evaluation of cardiovascular device function and performance is required prior to clinical implementation. Initial proof of concept investigations are conducted within in-vitro mock circulation loops, before proof of principle is demonstrated via in-vivo animal testing. To facilitate the rapid transition of cardiovascular devices through this development period, a testing apparatus was developed that closely models the natural human cardiovascular system haemodynamics. This mock circulation system accurately replicates cardiac function, coupled to systemic and pulmonary circulations. The physiological response produced by a number of clinical cardiovascular conditions can be actively controlled by variable parameters such as vascular resistance, arterial/venous compliance, ventricle contractility, heart rate, and heart /vascular volumes, while anatomical variations such as valve regurgitation and septal defects can be included. Auto-regulation of these parameters was attempted to reproduce the Frank-Starling mechanism, baroreceptor reflex, skeletal muscle pump, and postural changes. Steady state validation of loop performance was achieved by replicating the progression of a patient's clinical haemodynamics from heart failure, through VAD support, to heart transplantation. The system has been used to evaluate pulsatile and non-pulsatile ventricular assist devices, counter pulsation devices, non-invasive cardiac output monitors and cardiovascular stents. The interaction of these devices with the cardiovascular system was also investigated with regards to physiological control strategies and cannula placement. The system is a valuable tool for the accelerated progression of cardiovascular device development.

  18. Short-term exercise training improves the cardiovascular response to exercise in the postural orthostatic tachycardia syndrome

    PubMed Central

    Shibata, Shigeki; Fu, Qi; Bivens, Tiffany B; Hastings, Jeffrey L; Wang, Wade; Levine, Benjamin D

    2012-01-01

    Recent studies have suggested the presence of cardiac atrophy as a key component of the pathogenesis of the postural orthostatic tachycardia syndrome (POTS), similar to physical deconditioning. It has also been shown that exercise intolerance is associated with a reduced stroke volume (SV) in POTS, and that the high heart rate (HR) observed at rest and during exercise in these patients is due to this low SV. We tested the hypotheses that (a) circulatory control during exercise is normal in POTS; and (b) that physical ‘reconditioning’ with exercise training improves exercise performance in patients with POTS. Nineteen (18 women) POTS patients completed a 3 month training programme. Cardiovascular responses during maximal exercise testing were assessed in the upright position before and after training. Resting left ventricular diastolic function was evaluated by Doppler echocardiography. Results were compared with those of 10 well-matched healthy sedentary controls. A lower SV resulted in a higher HR in POTS at any given oxygen uptake () during exercise while the cardiac output ()– relationship was normal. was lower in POTS than controls (26.1 ± 1.0 (SEM) vs. 36.3 ± 0.9 ml kg−1 min−1; P < 0.001) due to a lower peak SV (65 ± 3 vs. 80 ± 5 ml; P = 0.009). After training in POTS, HR became lower at any given due to increased SV without changes in the – relationship. increased by 11% (P < 0.001) due to increased peak SV (P = 0.021) and was proportional to total blood volume. Peak HR was similar, but HR recovery from exercise was faster after training than before training (P = 0.036 for training and 0.009 for interaction). Resting diastolic function was mostly normal in POTS before training, though diastolic suction was impaired (P = 0.023). There were no changes in any Doppler index after training. These results suggest that short-term exercise training improves physical fitness and cardiovascular responses during exercise in patients with POTS. PMID

  19. Blunted GABA-mediated inhibition within the dorsomedial hypothalamus potentiates the cardiovascular response to emotional stress in rats fed a high-fat diet.

    PubMed

    Abreu, A R; de Abreu, A R; Santos, L T; de Souza, A A; da Silva, L G; Chianca, D A; de Menezes, R C

    2014-03-14

    Rats fed a high-fat diet (HFD) present an exaggerated endocrine response to stress conditions, which, like obesity, show a high correlation with cardiovascular diseases. Meanwhile the GABAergic neurotransmission within the dorsomedial hypothalamus (DMH) is involved in the regulation of the physiological responses during emotional stress. Here we evaluated the influence of obesity, induced by a HFD, on the cardiovascular responses induced by air jet stress in rats, and the role of the GABAergic tonus within the DMH in these changes. Our results showed that consumption of a HFD (45% w/w fat) for 9 weeks induced obesity and increases in baseline mean arterial pressure (MAP) and heart rate (HR). Moreover, obesity potentiated stress responsiveness, evidenced by the greater changes in MAP and HR induced by stress in obese rats. The injection of muscimol into the DMH reduced the maximal increases in HR and MAP induced by stress in both groups; however, the reduction in the maximal increases in MAP in the HFD group was less pronounced. Moreover, the injection of muscimol into the DMH of obese rats was less effective in reducing the stress-induced tachycardia, since the HR attained the same levels at the end of the stress paradigm as after the vehicle injection. Injection of bicuculline into DMH induced increases in MAP and HR in both groups. Nevertheless, obesity shortened the tachycardic response to bicuculline injection. These data show that obesity potentiates the cardiovascular response to stress in rats due to an inefficient GABAA-mediated inhibition within the DMH.

  20. Response-Based Strengthening in Task Shifting: Evidence from Shift Effects Produced by Errors

    ERIC Educational Resources Information Center

    Steinhauser, Marco; Hubner, Ronald

    2006-01-01

    The hypothesis is introduced that 1 source of shift costs is the strengthening of task-related associations occurring whenever an overt response is produced. The authors tested this account by examining shift effects following errors and error compensation processes. The authors predicted that following a specific type of error, called task…

  1. Flood-Producing Rainfall and Storm Event Hydrologic Response in Urban Watersheds near Baltimore, MD

    NASA Astrophysics Data System (ADS)

    Smith, B. K.; Smith, J. A.; Baeck, M. L.; Villarini, G.

    2012-12-01

    Previous work has shown a spectrum of storm event hydrologic response across watersheds in the Baltimore, MD metropolitan area. Differences in storm event hydrologic response between urban basins cannot be explained by impervious surface or land use alone. We further explore these differences through a closer look at flood-producing rainfall properties and through numerical experimentation using a watershed model. Rainfall analyses utilize a high resolution radar rainfall dataset (1-km and 15-min resolution, processed through Hydro-NEXRAD and bias corrected) for a ten-year period from 2000-2009. Spatial heterogeneities in flood-producing rainfall suggest that some urban basins may be more prone to flooding due to higher rainfall intensities over the basin. For example, Moores Run, the flashiest basin in the contiguous United States, is located near a rainfall maximum to the northeast of Baltimore. Spatial patterns of flood-producing rainfall vary between urban and non-urban basins. We examine contrasts in storm structure and evolution for storms producing flood in urban and non-urban watersheds. Storm event hydrologic response is examined through analyses using a watershed model of the Dead Run basin based on the Gridded Surface/ Subsurface Hydrologic Analysis (GSSHA) model. The model is used to explore the sensitivity of urban storm event hydrologic response to properties of urban soils, surface and storm drain network structure, and detention basin storage.

  2. Double-lumen tube intubation using video laryngoscopy causes a milder cardiovascular response compared to classic direct laryngoscopy

    PubMed Central

    Wei, Wei; Tian, Ming

    2016-01-01

    Objective: To determine whether there is a clinically relevant difference between the circulatory responses to double-lumen tube intubation (DLTI) with the GlideScope video laryngoscope versus the Macintosh direct laryngoscope. Methods: Eighty adult patients requiring double-lumen tubes for thoracic surgery were randomly and equally allocated to either a Macintosh direct laryngoscope group (DL group, n = 40) or a Glide Scope video laryngoscope group (GS group, n = 40). DLTI was performed after airway evaluations and induction of anesthesia. Systolic blood pressure (SBP) and heart rate (HR) were recorded before induction (baseline values), immediately before intubation (post-induction values), at intubation and after intubation. Rate-pressure-product (RPP), and the areas under SBP- and HR-time curves were calculated. All data obtained by the two devices were compared. Results: After laryngoscope insertion, SBP of DL and GS groups changed significantly differently (13.1% vs. 4.6%, P< 0.001), while HR changed similarly (17.2% vs. 14.6%, P = 0.074). One minute after intubation, both SBP and HR significantly increased in both groups (SBP: 11.6% vs. 11.9%; HR: 18.4% vs. 10.8%), but there were no significant differences between the two groups. RPP significantly increased in both groups after laryngoscope insertion (32.6%, P=0.001; 18.2%, P=0.002), and there was a significant difference between the two groups (P =0.001). Throughout intubation, the areas under SBP-time curves had a significant difference between the two groups (P = 0.042), while those under HR-time curves did not differ significantly (P=0.06). Conclusion: The intubation response was most significant upon laryngoscope insertion during the whole intubation process. The GlideScope video laryngoscope induced milder circulatory fluctuations than the Macintosh direct laryngoscope did, suggesting that DLTI using video laryngoscopy can help reduce the cardiovascular response to intubation. PMID:27022341

  3. The role of autacoids and the autonomic nervous system in cardiovascular responses to radio-frequency energy heating.

    PubMed

    Jauchem, J R

    2006-04-01

    Among the potential effects of exposure to high levels of radio-frequency energy (RFE) (which includes microwaves), an increase in body temperature is the primary consequence. Release of autacoids and activity of the autonomic nervous system may influence (or be directly responsible for) some of the physiological changes that occur in conjunction with this hyperthermia. The main focus of this review is the interaction of autacoids and the autonomic nervous system with cardiovascular changes during heating. Differences between environmental and RFE-induced heating (such as rate of temperature change and degree of skin vs. core heating) may be important when considering these effects. Antihistamines exhibited no beneficial effect on circulatory collapse during RFE-induced heating. The serotonergic blocker methysergide decreased survival time in rats during terminal RFE exposure, despite no effects on heart rate (HR) or blood pressure. Although blockade of platelet-activating factor resulted in lower HR before RFE exposure, there was a lack of effect on the subsequent increase in HR during heating. Nitric oxide did not contribute to the hypotension that occurs due to rapid heating by RFE exposure. There have been either no or very limited studies of effects of prostaglandins, bradykinin, or angiotensin on RFE-induced heating responses. beta-Adrenoceptor antagonism with propranolol resulted in significantly decreased survival times and lower final colonic temperatures during RFE exposure. A lack of effects of nadolol on survival time and temperature, coupled with its poor ability to traverse the blood-brain barrier, suggests that central beta-adrenergic stimulation rather than peripheral stimulation may alter thermoregulation. Effects of the autonomic nervous system (as studied by adrenoceptor blockade) on potassium changes during heating have not been fully investigated. Such changes could be important in animals' responses to RFE and other modalities of heating, and

  4. Renal and cardiovascular effects of caffeine: a dose-response study.

    PubMed

    Passmore, A P; Kondowe, G B; Johnston, G D

    1987-06-01

    The effects of increasing oral doses of caffeine (45, 90, 180 and 360 mg) on effective renal plasma flow (ERPF), plasma renin activity (PRA), serum electrolytes, plasma noradrenaline, blood pressure and heart rate were studied in eight healthy male volunteers. Urine volume was increased by 360 mg of caffeine only. At caffeine doses greater than 90 mg urinary sodium excretion was significantly increased. There were no changes in ERPF. Serum potassium was significantly reduced by 360 mg of caffeine. Caffeine increased systolic pressure in a dose related manner. Diastolic pressure was also increased, but not in relation to dose. A 360 mg dose of caffeine produced a late increase in heart rate. These changes were not associated with any alterations in PRA or in plasma noradrenaline. PMID:3297472

  5. The antigravity suit in neurosurgery. Cardiovascular responses in seated neurosurgical patients.

    PubMed

    Brodrick, P M; Ingram, G S

    1988-09-01

    The haemodynamic responses associated with inflation of the antigravity suit (G suit, aviation type) to 8.0 kPa were studied in a series of 40 patients who underwent neurosurgical operations in the sitting position. The study showed statistically significant increases in systolic arterial pressure (p less than 0.005) and mean central venous pressure (p less than 0.001) with inflation of the suit. The systolic arterial and mean central venous pressures remained significantly elevated immediately before deflation of the suit at the end of the operation (p less than 0.001 and p less than 0.005 respectively). The addition of 0.8-1.0 kPa positive end expiratory pressure during suit inflation was also investigated. A further increase in central venous pressure occurred but this did not achieve statistical significance.

  6. Cardiovascular and intestinal responses to oxidative and nitrosative stress during prolonged magnesium deficiency.

    PubMed

    Weglicki, William B; Chmielinska, Joanna J; Kramer, Jay H; Mak, I Tong

    2011-08-01

    In rodents with dietary magnesium deficiency (Mg deficiency), hypomagnesemia, occurs leading to a rise in circulating substance P from neuronal tissues to trigger systemic inflammatory stress in cardiac and intestinal tissues. Sustained elevations of substance P may result from impaired neutral endopeptidase (NEP) activity due to reactive oxygen and reactive nitrogen species. Associated increase in intestinal permeability includes infiltration of WBC and endotoxemia, which can further amplify the systemic inflammatory response that leads to impaired contractile function associated with up-regulation of the cardiac CD14 endotoxin receptor. The neurogenic signal transduction pathways that we have identified in the pro-oxidant/pro-inflammatory processes found with prolonged hypomagnesemia are described in this report. PMID:21747282

  7. The cardiovascular responses of the freshwater turtle Trachemys scripta to warming and cooling.

    PubMed

    Galli, Gina; Taylor, E W; Wang, Tobias

    2004-04-01

    Seven freshwater turtles Trachemys scripta were instrumented with flow probes and cannulated for blood pressure measurements. The turtles were warmed from 24 to 34 degrees C, and cooled down to 24 degrees C, with and without atropine. Animals exhibited a hysteresis of heart rate and blood flow to both the pulmonary and systemic circulations, which was not cholinergically mediated. Blood pressure remained constant during both warming and cooling, while systemic resistance decreased during heating and increased during cooling, indicating a barostatic response. There was a large right-to-left (R-L) shunt during warming and cooling in untreated animals, which remained relatively constant. Atropinisation resulted in a large L-R shunt, which decreased during warming and increased during cooling. Nevertheless, heating rates were the same in untreated and atropinised animals, and cooling rates were significantly longer in atropinised animals, indicating that shunt patterns contribute little to heat exchange. PMID:15037641

  8. Cardiovascular responses during arm exercise and orthostatic challenge in individuals with paraplegia.

    PubMed

    Raymond, J; Davis, G M; Clarke, J; Bryant, G

    2001-07-01

    In this study the cardiorespiratory responses during arm crank ergometry (ACE) performed at two submaximal intensities (30% and 50% of heart rate reserve) and moderate orthostatic challenge were investigated in individuals with paraplegia (PARA). The effect of concurrent electrical stimulation (ES)-induced leg muscle contractions on the responses to ACE during orthostatic challenge was also investigated. Eight PARA (T5-T12) and eight able-bodied (AB) individuals participated in this study, however only seven subjects from each group completed all tests and were used in subsequent data analyses. Oxygen uptake (VO2), heart rate (fc), stroke volume (SV) and cardiac output (Qc) were assessed during (1) ACE alone, (2) ACE and lower body negative pressure (ACE + LBNP), and, in PARA only, (3) ACE + LBNP with ES (ACE + LBNP+ ES). In both PARA and AB, ACE + LBNP decreased SV (by 13-18% and 20-23%, respectively) and increased fc (by 13-15% and 16%, respectively) compared to ACE alone. The decrease in SV was greater in AB than in PARA (significant group x trial interaction; both ACE intensities pooled), but there was no difference in the magnitude of increase in fc between groups. ES-induced leg muscle contractions increased SV (up to 16%) but did not change VO2 or Qc. The smaller reduction in SV from ACE to ACE + LBNP in PARA may indicate a mechanism by which adequate central blood volume can be maintained in the face of orthostatic challenge, despite the absence of supraspinal control below the spinal cord lesion. With ES-induced leg muscle contractions, the decrease in SV, which occurred during ACE + LBNP, was reversed via reactivation of the lower limb muscle pump and augmented venous return.

  9. Thermoregulatory, cardiovascular, and metabolic responses to mild caloric restriction in the Brown Norway rat.

    PubMed

    Aydin, Cenk; Gordon, Christopher J

    2013-07-01

    Caloric restriction (CR) has been demonstrated to prolong the life span of a variety of species. CR-induced reduction in core temperature (Tc) is considered a key mechanism responsible for prolonging life span in rodents; however, little is known about the regulation of CR-induced hypothermia as a function of the circadian cycle. We assessed how mild CR that resulted in a 10% reduction in body weight affected the 24 h patterns of Tc as well as heart rate (HR) and motor activity (MA) of the Brown Norway rat. Telemetered rats were allowed to feed for 20 weeks ad libitum (AL) or given a CR diet. Tc, HR, and MA of CR rats exhibited nocturnal reductions and diurnal elevations, opposite to that of AL rats. The effects of CR appeared to peak at ∼4 weeks. Metabolic rate (MR) and respiratory exchange ratio (RER) were measured overnight after 18 weeks of CR. MR and RER were elevated markedly at the time of feeding in CR rats and then declined during the night. We found that the pattern of Tc was altered with CR, characterized by elimination of high nocturnal Tc's typically observed in AL animals. In terms of mechanisms to prolong life span in CR animals, we suggest that the shift in the pattern of Tc during CR (i.e., elimination of high Tc's) may be as critical as the overall mean reduction in Tc. Future studies should address how the time of feeding may affect the thermoregulatory response in calorically restricted rats. PMID:24303105

  10. Seaweed supplements normalise metabolic, cardiovascular and liver responses in high-carbohydrate, high-fat fed rats.

    PubMed

    Kumar, Senthil Arun; Magnusson, Marie; Ward, Leigh C; Paul, Nicholas A; Brown, Lindsay

    2015-02-02

    Increased seaweed consumption may be linked to the lower incidence of metabolic syndrome in eastern Asia. This study investigated the responses to two tropical green seaweeds, Ulva ohnoi (UO) and Derbesia tenuissima (DT), in a rat model of human metabolic syndrome. Male Wistar rats (330-340 g) were fed either a corn starch-rich diet or a high-carbohydrate, high-fat diet with 25% fructose in drinking water, for 16 weeks. High-carbohydrate, high-fat diet-fed rats showed the signs of metabolic syndrome leading to abdominal obesity, cardiovascular remodelling and non-alcoholic fatty liver disease. Food was supplemented with 5% dried UO or DT for the final 8 weeks only. UO lowered total final body fat mass by 24%, systolic blood pressure by 29 mmHg, and improved glucose utilisation and insulin sensitivity. In contrast, DT did not change total body fat mass but decreased plasma triglycerides by 38% and total cholesterol by 17%. UO contained 18.1% soluble fibre as part of 40.9% total fibre, and increased magnesium, while DT contained 23.4% total fibre, essentially as insoluble fibre. UO was more effective in reducing metabolic syndrome than DT, possibly due to the increased intake of soluble fibre and magnesium.

  11. Attenuated cardiovascular hypertrophy and oxidant generation in response to angiotensin II infusion in glutaredoxin-1 knockout mice

    PubMed Central

    Bachschmid, Markus M.; Xu, Shanqin; Maitland-Toolan, Karlene A.; Ho, Ye-Shih; Cohen, Richard A.; Matsui, Reiko

    2010-01-01

    Glutaredoxin-1 (Glrx) is a thioltransferase that regulates protein S-glutathiolation. To elucidate the role of endogenous Glrx in cardiovascular disease, Glrx knockout (KO) mice were infused with angiotensin II (Ang II) for 6 days. After Ang II infusion, body weight and blood pressure were similar between WT and Glrx KO mice. However, compared to WT mice, Glrx KO mice demonstrated (1) less cardiac and aortic medial hypertrophy, (2) less oxidant generation in aorta assessed by dihydroethidium staining and nitrotyrosine, (3) decreased phosphorylation of Akt in the heart, and (4) less expression of inducible NOS (iNOS) in aorta and heart. In cultured embryonic fibroblasts from Glrx KO mice, S-glutathiolation of actin was enhanced and actin depolymerization was impaired after hydrogen peroxide stimulation compared with WT cells. Furthermore, oxidant generation in phorbol ester-stimulated fibroblasts and RAW 264.7 macrophage-like cells was lower with Glrx siRNA knockdown. These data indicate that Ang II-induced oxidant production and hypertrophic responses were attenuated in Glrx KO mice, which may result from impaired NADPH oxidase activation. PMID:20638471

  12. Matricryptic sites control tissue injury responses in the cardiovascular system: relationships to pattern recognition receptor regulated events.

    PubMed

    Davis, George E

    2010-03-01

    This review addresses new concepts related to the importance of how cells within the cardiovascular system respond to matricryptic sites generated from the extracellular matrix (ECM) following tissue injury. A model is presented whereby matricryptic sites exposed from the ECM result in activation of multiple cell surface receptors including integrins, scavenger receptors, and toll-like receptors which together are hypothesized to coactivate downstream signaling pathways which alter cell behaviors following tissue injury. Of great interest are the relationships between matricryptic fragments of ECM called matricryptins and other stimuli that activate cells during injury states such as released components from cells (DNA, RNA, cytoskeletal components such as actin) or products from infectious agents in innate immunity responses. These types of cell activating molecules, which are composed of repeating molecular elements, are known to interact with pattern recognition receptors that (i) are expressed from cell surfaces, (ii) are released from cells following tissue injury, or (iii) circulate as components of plasma. Thus, cell recognition of matricryptic sites from the ECM appears to be an important component of a broad cell and tissue sensory system to detect and respond to environmental cues generated following varied types of tissue injury.

  13. Seaweed supplements normalise metabolic, cardiovascular and liver responses in high-carbohydrate, high-fat fed rats.

    PubMed

    Kumar, Senthil Arun; Magnusson, Marie; Ward, Leigh C; Paul, Nicholas A; Brown, Lindsay

    2015-02-01

    Increased seaweed consumption may be linked to the lower incidence of metabolic syndrome in eastern Asia. This study investigated the responses to two tropical green seaweeds, Ulva ohnoi (UO) and Derbesia tenuissima (DT), in a rat model of human metabolic syndrome. Male Wistar rats (330-340 g) were fed either a corn starch-rich diet or a high-carbohydrate, high-fat diet with 25% fructose in drinking water, for 16 weeks. High-carbohydrate, high-fat diet-fed rats showed the signs of metabolic syndrome leading to abdominal obesity, cardiovascular remodelling and non-alcoholic fatty liver disease. Food was supplemented with 5% dried UO or DT for the final 8 weeks only. UO lowered total final body fat mass by 24%, systolic blood pressure by 29 mmHg, and improved glucose utilisation and insulin sensitivity. In contrast, DT did not change total body fat mass but decreased plasma triglycerides by 38% and total cholesterol by 17%. UO contained 18.1% soluble fibre as part of 40.9% total fibre, and increased magnesium, while DT contained 23.4% total fibre, essentially as insoluble fibre. UO was more effective in reducing metabolic syndrome than DT, possibly due to the increased intake of soluble fibre and magnesium. PMID:25648511

  14. Cardiovascular and behavioral responses of gray wolves to ketamine-xylazine immobilization and antagonism by yohimbine

    USGS Publications Warehouse

    Kreeger, T.J.; Faggella, A.M.; Seal, U.S.; Mech, L.D.; Callahan, M.; Hall, B.

    1987-01-01

    Adult wolves (Canis lupus) were immobilized with 6.6 mg/kg ketamine hydrochloride (KET) and 2.2 mg/kg xylazine hydrochloride (XYL) administered intramuscularly. Induction time was 4.6 +/- 0.3 min (mean +/- SE). Immobilization resulted in significant bradycardia and hypertension (P less than 0.05). Twenty min after induction, the wolves were given 0.05-0.60 mg/kg yohimbine hydrochloride (YOH). Yohimbine given intravenously produced dose-related increases in heart rate (HR) with doses greater than 0.15 mg/kg resulting in extreme tachycardia (greater than 300 bpm). All doses of YOH caused a temporary decrease in mean arterial blood pressure (MABP) with some individual animals manifesting profound hypotension (less than 30 torr) at doses greater than 0.15 mg/kg. Increasing the dose of YOH above 0.15 mg/kg did not significantly decrease either arousal or ambulation times. Administering YOH at 40 or 60 min after induction resulted in decreased arousal and ambulation times. Stimulation by weighing and taking repeated blood samples during anesthesia did not shorten arousal times. We recommend that wolves immobilized with XYL-KET be antagonized with doses of YOH less than 0.15 mg/kg.

  15. Brain vasopressin V(1) receptors contribute to enhanced cardiovascular responses to acute stress in chronically stressed rats and rats with myocardial infarcton.

    PubMed

    Cudnoch-Jedrzejewska, Agnieszka; Szczepanska-Sadowska, Ewa; Dobruch, Jakub; Gomolka, Ryszard; Puchalska, Liana

    2010-03-01

    The present study was designed to determine the role of central vasopressin 1 receptors (V(1)R) in the regulation of cardiovascular parameters in chronically stressed infarcted rats and sham-operated rats under resting conditions and during exposure to acute alarming stress. The experiments were performed on four groups of conscious sham-operated and four groups of infarcted rats subjected to intraventricular infusion of either vehicle or a V(1)R antagonist (V(1)RANT). Two groups of infarcted and two groups of sham-operated rats were subjected to mild chronic stressing. Mean arterial blood pressure (MABP) and heart rate (HR) were determined under resting conditions and after exposure to acute stress (air jet). During vehicle infusion, MABP and HR increases in response to acute stress in the infarcted rats not subjected to chronic stress, and in the infarcted and sham-operated chronically stressed rats, were significantly greater than in the sham-operated rats not exposed to chronic stress. However, MABP and HR responses to acute stress in the chronically stressed infarcted rats and chronically stressed sham-operated rats did not differ. V(1)RANT abolished differences in cardiovascular responses to acute stress between the experimental groups. Resting cardiovascular parameters were not affected by any of the experimental treatments. It is concluded that chronic stressing enhances the pressor and tachycardic responses to acute stress in the sham-operated rats but does not further intensify these responses in infarcted rats.The results provide evidence that central V(1)Rs are involved in potentiation of cardiovascular responses to acute stress in chronically stressed rats, infarcted rats, and chronically stressed infarcted rats.

  16. Aging, isometric strength and endurance, and cardiovascular responses to static effort.

    PubMed

    Petrofsky, J S; Lind, A R

    1975-01-01

    Previous studies on the relationship of age to isometric muscular strength are few, on isometric endurance rare, and on the physiological responses to static effort nonexistent. This investigation assessed the maximal handgrip strength, the duration of a fatiguing handgrip contraction at a tension of 40% of maximal strength and the heart rate and blood pressure during that contraction of 100 men aged from 22 to 62 yr. The subjects of this study were all men employed in a machine shop for a large aircraft corporation. The homogeneity of their occupations may well explain why, unlike previous reports, we found no change in muscular strength or muscular endurance with age. However, although heart rate increased during the contraction in all subjects, the increase in heart rate was greater in younger men. In contrast, while both systolic and diastolic blood pressures increased during the contraction in all subjects, the largest increase in systolic blood pressure was attained by the men in the older decades; there was no difference due to age in the diastolic blood pressures. The implications of these findings are discussed. PMID:1110248

  17. Switchable and responsive liquid crystal-functionalized microfibers produced via coaxial electrospinning

    NASA Astrophysics Data System (ADS)

    Lagerwall, Jan P. F.

    2012-03-01

    "Wearable technology" or "smart textiles" are concepts that are very rapidly gaining in attention around the world, as industry as well as academia are making major advances in integrating advanced devices with various textiles around our household. The technological challenges involved in this development are however considerable, calling for new solutions, new materials and truly original thinking. An attractive approach to realize certain classes of wearable devices may be to use textile fibers functionalized by responsive materials such as liquid crystals, normally not connected to textiles. We can produce non-woven textiles with such fibers by means of electrospinning, a technique for producing very thin polymer fibers that can be uniform or with core-sheath geometries. Since the core can be made out of traditionally non-spinnable materials we can use coaxial electrospinning (one fluid spun inside another) to produce composite fibers with a core of liquid crystal inside a polymer sheath. The resulting fibers constitute an entirely new configuration for applying liquid crystals, giving the fibers functionality and responsiveness. For instance, with a cholesteric core we can produce non-woven mats with iridescent color that can be tuned (or removed) e.g. by heating or cooling. In this paper I describe our method of producing these novel functionalized fibers and their characterization, and I will discuss the directions for future research and application possibilities, e.g. in clothing-integrated sensors and indicators.

  18. Polymorphisms in LEP and NPY genes modify the response to soluble fibre Plantago ovata husk intake on cardiovascular risk biomarkers.

    PubMed

    Crescenti, Anna; Solà, Rosa; Valls, Rosa M; Anguera, Anna; Arola, Lluís

    2013-01-01

    The satiating effect of fibre consumption has been related to gut hormones, such as peptide YY and leptin. These peptides may also influence cardiovascular (CVD) risk biomarkers. Nevertheless, there is wide interindividual variation in metabolic responses to fibre consumption. The objective was to investigate differences in the effects of soluble fibre, in the form of Plantago ovata husk (Po-husk) treatment, on CVD risk biomarkers according to selected polymorphisms in genes related to satiety. The study was a multi-centred, double-blind, placebo-controlled, parallel and randomised trial in mild-moderate hypercholesterolaemic patients (age range: 43-67 years). Eight polymorphisms in three genes related to satiety (LEP, NPY and PYY) were identified in 178 participants; 88 patients in the placebo (microcrystalline cellulose 14 g/day) group and 90 in the Po-husk (14 g/day) group, which had added to a low-saturated-fat diet for 8 weeks. The CVD biomarkers measured included the following: lipid profile, blood pressure (BP), glucose, insulin, hs-CRP, oxidised LDL and IL-6. Relative to the placebo, Po-husk consumption lowered the plasma total cholesterol concentration by 3.3 % according to rs7799039 polymorphism in the LEP gene (p < 0.05). Furthermore, the Po-husk reduced systolic BP (mean [95 % CI]) by -8 mmHg (-14.16; -1.90) and hs-CRP by 24.9 % in subjects with the AA genotype of the rs16147 polymorphism in the NPY gene (32 % of our total population; p < 0.05), which remained significant after Bonferroni correction. In conclusion, polymorphisms in the LEP and NPY genes potentiate the response to Po-husk, particularly the effects on systolic BP and the hs-CRP plasma concentration. PMID:22669627

  19. Polymorphisms in LEP and NPY genes modify the response to soluble fibre Plantago ovata husk intake on cardiovascular risk biomarkers.

    PubMed

    Crescenti, Anna; Solà, Rosa; Valls, Rosa M; Anguera, Anna; Arola, Lluís

    2013-01-01

    The satiating effect of fibre consumption has been related to gut hormones, such as peptide YY and leptin. These peptides may also influence cardiovascular (CVD) risk biomarkers. Nevertheless, there is wide interindividual variation in metabolic responses to fibre consumption. The objective was to investigate differences in the effects of soluble fibre, in the form of Plantago ovata husk (Po-husk) treatment, on CVD risk biomarkers according to selected polymorphisms in genes related to satiety. The study was a multi-centred, double-blind, placebo-controlled, parallel and randomised trial in mild-moderate hypercholesterolaemic patients (age range: 43-67 years). Eight polymorphisms in three genes related to satiety (LEP, NPY and PYY) were identified in 178 participants; 88 patients in the placebo (microcrystalline cellulose 14 g/day) group and 90 in the Po-husk (14 g/day) group, which had added to a low-saturated-fat diet for 8 weeks. The CVD biomarkers measured included the following: lipid profile, blood pressure (BP), glucose, insulin, hs-CRP, oxidised LDL and IL-6. Relative to the placebo, Po-husk consumption lowered the plasma total cholesterol concentration by 3.3 % according to rs7799039 polymorphism in the LEP gene (p < 0.05). Furthermore, the Po-husk reduced systolic BP (mean [95 % CI]) by -8 mmHg (-14.16; -1.90) and hs-CRP by 24.9 % in subjects with the AA genotype of the rs16147 polymorphism in the NPY gene (32 % of our total population; p < 0.05), which remained significant after Bonferroni correction. In conclusion, polymorphisms in the LEP and NPY genes potentiate the response to Po-husk, particularly the effects on systolic BP and the hs-CRP plasma concentration.

  20. Cardiovascular responses to locomotor activity and feeding in unrestrained three-toed sloths, Bradypus variegatus.

    PubMed

    Duarte, D P F; Jaguaribe, A M; Pedrosa, M A C; Clementino, A C C R; Barbosa, A A; Silva, A F V; Gilmore, D P; Da Costa, C P

    2004-10-01

    Heart rate (HR) and systolic (SBP), diastolic (DBP) and mean (MBP) blood pressure were recorded by biotelemetry in nine conscious unrestrained sloths for 1 min every 15 min over a 24-h period. The animals were allowed to freely move in an acoustically isolated and temperature-controlled (24 +/- 1 degree C) experimental room with light-dark cycle (12/12 h). Behavior was closely monitored through a unidirectional visor and classified as resting (sitting or suspended), feeding (chewing and swallowing embauba leaves, Cecropia adenops), or locomotor activity around the tree trunk or on the room floor. Locomotor activity caused statistically significant increases in SBP (+8%, from 121 +/- 22 to 131 +/- 18 mmHg), DBP (+7%, from 86 +/- 17 to 92 +/- 10 mmHg), MBP (+8%, from 97 +/- 19 to 105 +/- 12 mmHg), and HR (+14%, from 84 +/- 15 to 96 +/- 15 bpm) compared to resting values, indicating a possible major influence of the autonomic nervous system on the modulation of cardiac function during this behavior. During feeding, the increase in blood pressure was even higher (SBP +27%, from 119 +/- 21 to 151 +/- 21 mmHg; DBP +21%, from 85 +/- 16 to 103 +/- 15 mmHg; MBP +24%, from 96 +/- 17 to 119 +/- 17 mmHg), while HR remained at 14% (from 84 +/- 15 to 96 +/- 10 bpm) above resting values. The proportionally greater increase in blood pressure than in HR during feeding suggests an increase in peripheral vascular resistance as part of the overall response to this behavior.

  1. Effects of hypnosis on plasma proenkephalin peptide F and perceptual and cardiovascular responses during submaximal exercise.

    PubMed

    Kraemer, W J; Lewis, R V; Triplett, N T; Koziris, L P; Heyman, S; Noble, B J

    1992-01-01

    Little information is available concerning the influence of subconscious mechanisms on neuroendocrine function, more specifically, proenkephalin peptide F release. Ten men [5 middle distance runners (21.6 (SD 0.54 years) and 5 untrained men (24.0 (SD 4.3 years)] consented to be volunteers in this investigation. Submaximal exercise intensities of 25% and 50% of peak oxygen consumption (VO2) (8 min stages) were used for both the control and hypnosis treatments. A traditional hypnotic induction was used, with the suggestion of two higher intensities of exercise stress (50% and 75% peak VO2) previously experienced in familiarization and testing by each subject. Each minute oxygen consumption was measured using open circuit spirometry, heart rate via an ECG, and ratings of perceived exertion (RPE) using the Borg scale. Plasma peptide F immunoreactivity (ir) [preproenkephalin-(107-140)] in blood sampled from an indwelling cannula was measured by radioimmunoassay at 7-8 min of each stage of the exercise test. Expected significant increases were observed for all cardiorespiratory and perceptual variables over the increasing exercise intensities and there were no significant differences between trained and untrained groups for peptide F if response patterns. Hypnosis did not significantly affect peptide F ir concentrations (P > 0.05) and did not significantly alter exercise heart rate, RPE or minute ventilation (P > 0.05). However, hypnosis did significantly increase oxygen consumption during exercise (P = 0.0095) but not of the magnitude needed for the metabolic demands of the higher exercise intensities. Thus, traditional hypnosis was unable to make functionally significant changes in the cardiorespiratory variables.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1483448

  2. Short-term physiological responses of wild and hatchery-produced red drum during angling

    USGS Publications Warehouse

    Gallman, E.A.; Isely, J.J.; Tomasso, J.R.; Smith, T.I.J.

    1999-01-01

    Serum cortisol concentrations, plasma glucose concentrations, plasma lactate concentrations, and plasma osmolalities increased in red drum Sciaenops ocellatus (26.0-65.5 cm total length) during angling in estuarine waters (17-33 g/L salinity, 21-31??C). Angling time varied from as fast as possible (10 s) to the point when fish ceased resisting (up to 350 s). The increases in the physiological characteristics were similar in wild and hatchery-produced fish. This study indicates that hatchery-produced red drum may be used in catch-and-release studies to simulate the responses of wild fish.

  3. Anabolic steroids and cardiovascular risk.

    PubMed

    Angell, Peter; Chester, Neil; Green, Danny; Somauroo, John; Whyte, Greg; George, Keith

    2012-02-01

    Recent reports from needle exchange programmes and other public health initiatives have suggested growing use of anabolic steroids (AS) in the UK and other countries. Data indicate that AS use is not confined to body-builders or high-level sportsmen. Use has spread to professionals working in emergency services, casual fitness enthusiasts and subelite sportsmen and women. Although the precise health consequences of AS use is largely undefined, AS use represents a growing public health concern. Data regarding the consequences of AS use on cardiovascular health are limited to case studies and a modest number of small cohort studies. Numerous case studies have linked AS use with a variety of cardiovascular disease (CVD) events or endpoints, including myocardial infarction, stroke and death. Large-scale epidemiological studies to support these links are absent. Consequently, the impact of AS use upon known CVD risk factors has been studied in relatively small, case-series studies. Data relating AS use to elevated blood pressure, altered lipid profiles and ECG abnormalities have been reported, but are often limited in scope, and other studies have often produced equivocal outcomes. The use of AS has been linked to the appearance of concentric left ventricular hypertrophy as well as endothelial dysfunction but the data again remains controversial. The mechanisms responsible for the negative effect of AS on cardiovascular health are poorly understood, especially in humans. Possibilities include direct effects on myocytes and endothelial cells, reduced intracellular Ca2+ levels, increased release of apoptogenic factors, as well as increased collagen crosslinks between myocytes. New data relating AS use to cardiovascular health risks are emerging, as novel technologies are developed (especially in non-invasive imaging) that can assess physiological structure and function. Continued efforts to fully document the cardiovascular health consequences of AS use is important to

  4. Transcriptomic responses of the calanoid copepod Calanus finmarchicus to the saxitoxin producing dinoflagellate Alexandrium fundyense

    PubMed Central

    Roncalli, Vittoria; Cieslak, Matthew C.; Lenz, Petra H.

    2016-01-01

    In the Gulf of Maine, the copepod Calanus finmarchicus co-occurs with the neurotoxin-producing dinoflagellate, Alexandrium fundyense. The copepod is resistant to this toxic alga, but little is known about other effects. Gene expression profiles were used to investigate the physiological response of females feeding for two and five days on a control diet or a diet containing either a low or a high dose of A. fundyense. The physiological responses to the two experimental diets were similar, but changed between the time points. At 5-days the response was characterized by down-regulated genes involved in energy metabolism. Detoxification was not a major component of the response. Instead, genes involved in digestion were consistently regulated, suggesting that food assimilation may have been affected. Thus, predicted increases in the frequency of blooms of A. fundyense could affect C. finmarchicus populations by changing the individuals’ energy budget and reducing their ability to build lipid reserves. PMID:27181871

  5. L-Asparaginase II Produced by Salmonella Typhimurium Inhibits T Cell Responses and Mediates Virulence

    PubMed Central

    Kullas, Amy L.; McClelland, Michael; Yang, Hee-Jeong; Tam, Jason W.; Torres, AnnMarie; Porwollik, Steffen; Mena, Patricio; McPhee, Joseph B.; Bogomolnaya, Lydia; Andrews-Polymenis, Helene; van der Velden, Adrianus W.M.

    2013-01-01

    SUMMARY Salmonella enterica serovar Typhimurium avoids clearance by the host immune system by suppressing T cell responses; however, the mechanisms that mediate this immunosuppression remain unknown. We show that S. Typhimurium inhibit T cell responses by producing L-Asparaginase II, which catalyzes the hydrolysis of L-asparagine to aspartic acid and ammonia. L-Asparaginase II is necessary and sufficient to suppress T cell blastogenesis, cytokine production, and proliferation and to downmodulate expression of the T cell receptor. Furthermore, S. Typhimurium-induced inhibition of T cells in vitro is prevented upon addition of L-asparagine. S. Typhimurium lacking the L-Asparaginase II gene (STM3106) are unable to inhibit T cell responses and exhibit attenuated virulence in vivo. L-Asparaginases are used to treat acute lymphoblastic leukemia through mechanisms that likely involve amino acid starvation of leukemic cells, and these findings indicate that pathogens similarly use L-asparagine deprivation to limit T cell responses. PMID:23245323

  6. Effect of Pregabalin on Cardiovascular Responses to Exercise and Postexercise Pain and Fatigue in Fibromyalgia: A Randomized, Double-Blind, Crossover Pilot Study

    PubMed Central

    White, Andrea T.; Light, Kathleen C.; Bateman, Lucinda; Hughen, Ronald W.; Vanhaitsma, Timothy A.; Light, Alan R.

    2015-01-01

    Pregabalin, an approved treatment for fibromyalgia (FM), has been shown to decrease sympathetic nervous system (SNS) activity and inhibit sympathetically maintained pain, but its effects on exercise responses have not been reported. Methods. Using a randomized double-blind crossover design, we assessed the effect of 5 weeks of pregabalin (versus placebo) on acute cardiovascular and subjective responses to moderate exercise in 19 FM patients. Blood pressure (BP), heart rate (HR), and ratings of perceived exertion (RPE) during exercise and ratings of pain, physical fatigue, and mental fatigue before, during, and for 48 hours after exercise were compared in patients on pregabalin versus placebo and also versus 18 healthy controls. Results. On placebo, exercise RPE and BP were significantly higher in FM patients than controls (p < 0.04). Pregabalin responders (n = 12, defined by patient satisfaction and symptom changes) had significantly lower exercise BP, HR, and RPE on pregabalin versus placebo (p < 0.03) and no longer differed from controls (p > 0.26). Cardiovascular responses of nonresponders (n = 7) were not altered by pregabalin. In responders, pregabalin improved ratings of fatigue and pain (p < 0.04), but negative effects on pain and fatigue were seen in nonresponders. Conclusions. These preliminary findings suggest that pregabalin may normalize cardiovascular and subjective responses to exercise in many FM patients. PMID:27026828

  7. DIFFERENCES IN CARDIOVASCULAR RESPONSE TO PM EXPOSURE BETWEEN SPONTANEOUSLY HYPERTENSIVE STROKE-PRONE (SHSP) AND WISTAR-KYOTO (WKY) RATS.

    EPA Science Inventory

    ABSTRACT BODY: Epidemiological studies have shown that cardiovascular morbidity and mortality are associated with exposure to elevated levels of ambient particulate matter (PM), notably in people with pre-existing cardiopulmonary disease. To better understand the mechanisms of PM...

  8. Rat Models of Cardiovascular Disease Demonstrate Distinctive Pulmonary Gene Expressions for Vascular Response Genes: Impact of Ozone Exposure

    EPA Science Inventory

    Comparative gene expression profiling of multiple tissues from rat strains with genetic predisposition to diverse cardiovascular diseases (CVD) can help decode the transcriptional program that governs organ-specific functions. We examined expressions of CVD genes in the lungs of ...

  9. Variability and cardiovascular homeostasis.

    PubMed

    Hughson, R L; Gharib, C

    1995-01-01

    The inability to maintain the upright posture due to a failure in the arterial blood pressure regulatory mechanisms on return from space travel or after a period of head down tilt bed rest (HDBR) is the ultimate sign of cardiovascular deconditioning. Yet, the final response of syncope is potentially heralded by a series of precursor events that can be quantified and analyzed in new, more insightful ways to attempt to understand the integrative nature of autonomic control of the cardiovascular system.

  10. Cardiovascular Effects of Caffeine

    PubMed Central

    Myers, Martin G.

    1992-01-01

    A review of the literature on the cardiovascular effects of caffeine indicates that moderate caffeine consumption does not cause cardiac arrhythmias, hypertension, or an increased incidence of coronary heart disease. Caffeine use is often associated with atherogenic behavior, such as cigarette smoking. Failure to take into account covariables for cardiovascular disease could be responsible for commonly held misconceptions about caffeine and heart disease. PMID:21221403

  11. Ethnicity and genetics are more important than diabetes mellitus and hypertension in producing cardiovascular events in patients with the metabolic syndrome: emphasis in the Puerto Rico population.

    PubMed

    Altieri, Pablo I; Marcial, José M; Banchs, Héctor; Escobales, Nelson; Crespo, María

    2013-01-01

    Metabolic syndrome is a cluster of risk factors for cardiovascular disease that affects an estimated 50 million Americans. The present article reviews the metabolic syndrome with respect to its definition, epidemiology, pathophysiology and management. A primary focus in research has been to elucidate the processes determined to cause insulin resistance, the fundamental mechanism underlying the metabolic syndrome. Namely, the incidence, component characteristics and complications of the metabolic syndrome in the island of Puerto Rico are described alongside the fact that the metabolic syndrome may be milder in Puerto Rico than in the mainland United States because it is characterized by less aggressive coronary disease and a relatively normal lipid profile. This suggests that the cardiovascular complications are more influenced by genetics and culture than diabetes mellitus and hypertension.

  12. [Methodological approaches to the hygienic evaluation of total artificial lighting of classrooms with different light sources on the basis of the response of the cardiovascular system of schoolchildren].

    PubMed

    Teksheva, L M; Zvezdina, I V

    2014-01-01

    Hygienic evaluation of innovative equipment in educational institutions requires the use of appropriate methods permitting to establish valuable criterias for the effectiveness of the application of new technologies. The study of the response of the cardiovascular system of schoolchildren under using different light sources allowed to establish the increase in adaptive capacities and the improvement of the functional state of the organism in LED in comparison with fluorescent lighting.

  13. Cardiovascular Deconditioning

    NASA Technical Reports Server (NTRS)

    Charles, John B.; Fritsch-Yelle, Janice M.; Whitson, Peggy A.; Wood, Margie L.; Brown, Troy E.; Fortner, G. William

    1999-01-01

    Spaceflight causes adaptive changes in cardiovascular function that may deleteriously affect crew health and safety. Over the last three decades, symptoms of cardiovascular changes have ranged from postflight orthostatic tachycardia and decreased exercise capacity to serious cardiac rhythm disturbances during extravehicular activities (EVA). The most documented symptom of cardiovascular dysfunction, postflight orthostatic intolerance, has affected a significant percentage of U.S. Space Shuttle astronauts. Problems of cardiovascular dysfunction associated with spaceflight are a concern to NASA. This has been particularly true during Shuttle flights where the primary concern is the crew's physical health, including the pilot's ability to land the Orbiter, and the crew's ability to quickly egress and move to safety should a dangerous condition arise. The study of astronauts during Shuttle activities is inherently more difficult than most human research. Consequently, sample sizes have been small and results have lacked consistency. Before the Extended Duration Orbiter Medical Project (EDOMP), there was a lack of normative data on changes in cardiovascular parameters during and after spaceflight. The EDOMP for the first time allowed studies on a large enough number of subjects to overcome some of these problems. There were three primary goals of the Cardiovascular EDOMP studies. The first was to establish, through descriptive studies, a normative data base of cardiovascular changes attributable to spaceflight. The second goal was to determine mechanisms of cardiovascular changes resulting from spaceflight (particularly orthostatic hypotension and cardiac rhythm disturbances). The third was to evaluate possible countermeasures. The Cardiovascular EDOMP studies involved parallel descriptive, mechanistic, and countermeasure evaluations.

  14. Comparison of cardiovascular response to combined static-dynamic effort, postprandial dynamic effort and dynamic effort alone in patients with chronic ischemic heart disease

    SciTech Connect

    Hung, J.; McKillip, J.; Savin, W.; Magder, S.; Kraus, R.; Houston, N.; Goris, M.; Haskell, W.; DeBusk, R.

    1982-06-01

    The cardiovascular responses to combined static-dynamic effort, postprandial dynamic effort and dynamic effort alone were evaluated by upright bicycle ergometry during equilibrium-gated blood pool scintigraphy in 24 men, mean age 59 +/- 8 years, with chronic ischemic heart disease. Combined static-dynamic effort and the postprandial state elicited a peak cardiovascular response similar to that of dynamic effort alone. Heart rate, intraarterial systolic and diastolic pressures, rate-pressure product and ejection fraction were similar for the three test conditions at the onset of ischemia and at peak effort. The prevalence and extent of exercise-induced ischemic left ventricular dysfunction, ST-segment depression, angina pectoris and ventricular ectopic activity were also similar during the three test conditions. Direct and indirect measurements of systolic and diastolic blood pressure were highly correlated. The onset of ischemic ST-segment depression and angina pectoris correlated as strongly with heart rate alone as with the rate-pressure product during all three test conditions. The cardiovascular response to combined static-dynamic effort and to postprandial dynamic effort becomes more similar to that of dynamic effort alone as dynamic effort reaches a symptom limit. If significant ischemic and arrhythmic abnormalities are absent during symptom-limited dynamic exercise testing, they are unlikely to appear during combined static-dynamic or postprandial dynamic effort.

  15. The response of primary producer assemblages to mitigation measures to reduce eutrophication in a temperate estuary

    NASA Astrophysics Data System (ADS)

    Leston, S.; Lillebø, A. I.; Pardal, M. A.

    2008-05-01

    The Mondego estuary is a well-described system located on the North Atlantic Ocean, where cultural eutrophication progressed over the last decades of the 20th century. Consequently, and due to a large productivity of Ulva spp., Zostera noltii meadows were severely reduced with a concomitant decrease in environmental quality. In 1998, experimental mitigation measures were implemented, via changes in hydrology to increase circulation and diversion of nutrient-rich freshwater inflow, to reverse the process in the most affected area of the estuary - its South arm. The objective of this study was to assess the differences in response of primary producer assemblages to the implemented measures to reduce eutrophication. Results show that the mean concentrations of DIN suffered a notorious decrease due to a significant reduction in the ammonium concentration in the water column, while DIP increased significantly. Primary producer assemblages showed different responses to these changes: phytoplankton, measured as concentration of chlorophyll a, did not show any significant changes; green macroalgae, mostly Ulva spp., suffered a large reduction in biomass, whereas Gracilaria gracilis and the macrophyte Zostera noltii biomasses increased greatly. Results show that phytoplankton biomass has remained constant and suggest that the reduction in ammonium could have been responsible for the changes in the green macroalgal biomass. Light was the most likely factor in the response of seagrass whereas red macroalgal reaction seemed to be dependent on both light and ammonium.

  16. Recycling research on spent fluorescent lamps on the basis of extended producer responsibility in China.

    PubMed

    Peng, Lihong; Wang, Yejun; Chang, Chang-Tang

    2014-11-01

    Mercury is a physiological toxin released by spent fluorescent lamps (SFLs) and is considered a serious pollutant. As the world's largest producer of fluorescent lamps, China suffers from SFL pollution because of inefficient recycling and management of SFLs. Drawing upon the most successful practices worldwide, this paper suggests the recycling of SFLs on the basis of the extended producer responsibility (EPR) system in China. Manufacturers and importers are the main parties responsible for the take-back, recycling, and disposal ofSFLs in the EPR system. In view of the situation in China and to address the objectives of the EPR system, this paper recommends the implementation of a third-party take-back mode for small- and medium-scale enterprises and of a takeback mode for large enterprises to be carried out by original equipment manufacturers. This paper suggests an extended responsibility fund to finance and support the SFL recycling system and discusses in detail the different recycling network systems and fund flows of the two take-back modes. By conducting a case study, the authors determine that the subsidy rate for SFLs that a recycling company can obtain from the extended responsibility fund for recycling and disposing of lamps can be set at $1.35/kg. The authors also predict the levy level that fluorescent lamp manufacturers must submit.

  17. Effects of Music on Cardiovascular Responses in Men with Essential Hypertension Compared with Healthy Men Based on Introversion and Extraversion

    PubMed Central

    Namdar, Hossein; Taban Sadeghi, Mohammadreza; Sabourimoghaddam, Hassan; Sadeghi, Babak; Ezzati, Davoud

    2014-01-01

    Introduction: The present research investigated the effects of two different types of music on cardiovascular responses in essential hypertensive men in comparison with healthy men based on introversion and extraversion. Methods: One hundred and thirteen hypertensive men referred to Madani Heart Hospital in Tabriz completed the NEO-FFI Questionnaire and after obtaining acceptable scores were classified in four groups: introvert patients, extravert patients, introvert healthy subjects, and extravert healthy subjects (each group with 25 samples with age range 31-50). Baseline blood pressure and heart rate of each subject was recorded without any stimulus. Then subjects were exposed to slow-beat music and blood pressure and heart rate were recorded. After15 minute break, and a little cognitive task for distraction, subjects were exposed to fast-beat music and blood pressure and heart rate were recorded again. Results: Multivariate analysis of covariance (MANCOVA) test showed that extravert patient subjects obtained greater reduction in systolic blood pressure and heart rate after presenting slow-beat music compared with introvert patients (P= 0.035, and P= 0.033 respectively). And extravert healthy subjects obtained greater reduction in heart rate after presenting slow-beat music compared with introvert healthy subjects (P= 0.036). However, there are no significant differences between introvert and extravert groups in systolic and diastolic blood pressure and heart rate after presenting fast-beat music. Conclusion: Based on our results, introvert subjects experience negative emotions more than extravert subjects and negative emotions cause less change in blood pressure in these subjects compared with extravert subjects. PMID:25320667

  18. A dose-response study of consuming high-fructose corn syrup–sweetened beverages on lipid/lipoprotein risk factors for cardiovascular disease in young adults123456

    PubMed Central

    Medici, Valentina; Bremer, Andrew A; Lee, Vivien; Lam, Hazel D; Nunez, Marinelle V; Chen, Guoxia X; Keim, Nancy L; Havel, Peter J

    2015-01-01

    Background: National Health and Nutrition Examination Survey data show an increased risk of cardiovascular disease (CVD) mortality with an increased intake of added sugar. Objective: We determined the dose-response effects of consuming beverages sweetened with high-fructose corn syrup (HFCS) at zero, low, medium, and high proportions of energy requirements (Ereq) on circulating lipid/lipoprotein risk factors for CVD and uric acid in adults [age: 18–40 y; body mass index (in kg/m2): 18–35]. Design: We conducted a parallel-arm, nonrandomized, double-blinded intervention study in which adults participated in 3.5 inpatient days of baseline testing at the University of California Davis Clinical and Translational Science Center’s Clinical Research Center. Participants then consumed beverages sweetened with HFCS at 0% (aspartame sweetened, n = 23), 10% (n = 18), 17.5% (n = 16), or 25% (n = 28) of Ereq during 13 outpatient days and during 3.5 inpatient days of intervention testing at the research center. We conducted 24-h serial blood collections during the baseline and intervention testing periods. Results: Consuming beverages containing 10%, 17.5%, or 25% Ereq from HFCS produced significant linear dose-response increases of lipid/lipoprotein risk factors for CVD and uric acid: postprandial triglyceride (0%: 0 ± 4; 10%: 22 ± 8; 17.5%: 25 ± 5: 25%: 37 ± 5 mg/dL, mean of Δ ± SE, P < 0.0001 effect of HFCS-dose), fasting LDL cholesterol (0%: −1.0 ± 3.1; 10%: 7.4 ± 3.2; 17.5%: 8.2 ± 3.1; 25%: 15.9 ± 3.1 mg/dL, P < 0.0001), and 24-h mean uric acid concentrations (0%: −0.13 ± 0.07; 10%: 0.15 ± 0.06; 17.5%: 0.30 ± 0.07; 25%: 0.59 ± 0.09 mg/dL, P < 0.0001). Compared with beverages containing 0% HFCS, all 3 doses of HFCS-containing beverages increased concentrations of postprandial triglyceride, and the 2 higher doses increased fasting and/or postprandial concentrations of non–HDL cholesterol, LDL cholesterol, apolipoprotein B, apolipoprotein CIII, and

  19. Predicting in vivo cardiovascular properties of β-blockers from cellular assays: a quantitative comparison of cellular and cardiovascular pharmacological responses.

    PubMed

    Baker, Jillian G; Kemp, Philip; March, Julie; Fretwell, Laurice; Hill, Stephen J; Gardiner, Sheila M

    2011-12-01

    β-Adrenoceptor antagonists differ in their degree of partial agonism. In vitro assays have provided information on ligand affinity, selectivity, and intrinsic efficacy. However, the extent to which these properties are manifest in vivo is less clear. Conscious freely moving rats, instrumented for measurement of heart rate (β1; HR) and hindquarters vascular conductance (β2; HVC) were used to measure receptor selectivity and ligand efficacy in vivo. CGP 20712A caused a dose-dependent decrease in basal HR (P<0.05, ANOVA) at 5 doses between 6.7 and 670 μg/kg (i.v.) and shifted the dose-response curve for isoprenaline to higher agonist concentrations without altering HVC responses. In contrast, at doses of 67 μg/kg (i.v.) and above, ICI 118551 substantially reduced the HVC response to isoprenaline without affecting HR responses. ZD 7114, xamoterol, and bucindolol significantly increased basal HR (ΔHR: +122 ± 12, + 129 ± 11, and + 59 ± 11 beats/min, respectively; n=6), whereas other β-blockers caused significant reductions (all at 2 mg/kg i.v.). The agonist effects of xamoterol and ZD 7114 were equivalent to that of the highest dose of isoprenaline. Bucindolol, however, significantly antagonized the response to the highest doses isoprenaline. An excellent correlation was obtained between in vivo and in vitro measures of β1-adrenoceptor efficacy (R(2)=0.93; P<0.0001). PMID:21865315

  20. Effects of the administration of a catalase inhibitor into the fourth cerebral ventricle on cardiovascular responses in spontaneously hypertensive rats exposed to sidestream cigarette smoke

    PubMed Central

    Valenti, Vitor E.; de Abreu, Luiz Carlos; Fonseca, Fernando L. A.; Adami, Fernando; Sato, Monica A.; Vanderlei, Luiz Carlos M.; Ferreira, Lucas Lima; Rodrigues, Luciano M.; Ferreira, Celso

    2013-01-01

    OBJECTIVE: Previous studies have demonstrated a relationship between brain oxidative stress and cardiovascular regulation. We evaluated the effects of central catalase inhibition on cardiovascular responses in spontaneously hypertensive rats exposed to sidestream cigarette smoke. METHODS: Male Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SH) (16 weeks old) were implanted with a stainless steel guide cannula leading into the fourth cerebral ventricle (4th V). The femoral artery and vein were cannulated for arterial pressure and heart rate measurement and drug infusion, respectively. The rats were exposed to sidestream cigarette smoke for 180 minutes/day, 5 days/week for 3 weeks (CO: 100-300 ppm). The baroreflex was tested using a pressor dose of phenylephrine (8 μg/kg, bolus) and a depressor dose of sodium nitroprusside (50 μg/kg, bolus). Cardiovascular responses were evaluated before and 5, 15, 30 and 60 minutes after injection of a catalase inhibitor (3-amino-1,2,4-triazole, 0.001 g/100 μL) into the 4th V. RESULTS: Vehicle administration into the 4th V did not affect the cardiovascular response, whereas administration of the central catalase inhibitor increased the basal HR and attenuated the bradycardic peak (p<0.05) to a greater extent in WKY rats exposed to sidestream cigarette smoke than in WKY rats exposed to fresh air. However, in spontaneously hypertensive rats, the effect of the catalase inhibitor treatment was stronger in the fresh air condition (p<0.05). CONCLUSION: Administration of a catalase inhibitor into the 4th V combined with exposure to sidestream cigarette smoke has a stronger effect in WKY rats than in SH rats. PMID:23778493

  1. Impaired cardiovascular function caused by different stressors elicits a common pathological and transcriptional response in zebrafish embryos.

    PubMed

    Chen, Jing

    2013-09-01

    Zebrafish embryos have been widely used to study the genes and processes needed for normal vertebrate heart development. We recently observed that exposure to 2,3,7,8-tetra-chlorodibenzo-p-dioxin (TCDD) or retinoic acid (RA) produces very similar signs of heart failure in developing zebrafish via divergent molecular pathways. The fact that diverse stressors and mutations cause severe pericardial edema and circulatory collapse in developing zebrafish has been largely unexplored. We hypothesized that unrelated chemicals can trigger a common pathological response leading to the same end-stage heart failure. To test this hypothesis, we compared the effects of TCDD, RA, carbaryl, valproic acid, and morpholino oligonucleotide (MO) knockdown of TBX5 on the developing heart in zebrafish embryos. These model stressors have all been previously reported to affect zebrafish heart development, and elicited very similar signs of embryonic heart failure. Microarray analysis showed that one cluster of 92 transcripts affected by these different treatments was significantly downregulated by all treatments. This gene cluster is composed of transcripts required for chromosome assembly, DNA replication, and cell cycle progression. We refer to this cluster as the cell cycle gene cluster (CCGC). Immunohistochemistry revealed that downregulation of the CCGC precedes a halt in cardiomyocyte proliferation in the hearts of zebrafish exposed to any of the treatments. Previous work has shown that the initial response to TCDD is a decrease in cardiac output. Since this precedes the signs of edema, heart failure, and fall in CCGC expression, we postulated that any factor that decreases cardiac output will produce the same syndrome of heart failure responses. To test this, we used MO knockdown of cardiac troponin T2 (TNNT2) to specifically block contractility. The TNNT2-MO produced exactly the same signs of cardiotoxicity as the other treatments, including downregulation of the signature CCGC

  2. Immunoglobulin classes of antibodies produced in the primary and secondary responses in man*

    PubMed Central

    Bandilla, K. K.; McDuffie, F. C.; Gleich, G. J.

    1969-01-01

    A method, radio-immunoprecipitation, is described which measures the antibody in the different classes in whole sera by its antigen binding capacity. In nineteen of twenty-four individuals immunized with Limulus polyphemus haemocyanin, haemagglutinating antibodies were produced in the primary response, but in only five were amounts significant enough to measure by radio-immunoprecipitation. In these five individuals, the primary response was characterized by an early appearance of IgM and IgA antibodies; IgG antibody was detectable but only in small amounts and not before the 18th day after immunization. All twenty-four individuals responded to a secondary injection. A sharp rise in IgG antibody after the secondary injection is typical of the secondary response. A definite but much lower anamnestic response for IgM and IgA is observed. The difference is so uniform and striking that it may well be characteristic for some primary responses in man. PMID:4189127

  3. Autophagy in cardiovascular biology

    PubMed Central

    Lavandero, Sergio; Chiong, Mario; Rothermel, Beverly A.; Hill, Joseph A.

    2015-01-01

    Cardiovascular disease is the leading cause of death worldwide. As such, there is great interest in identifying novel mechanisms that govern the cardiovascular response to disease-related stress. First described in failing hearts, autophagy within the cardiovascular system has been widely characterized in cardiomyocytes, cardiac fibroblasts, endothelial cells, vascular smooth muscle cells, and macrophages. In all cases, a window of optimal autophagic activity appears to be critical to the maintenance of cardiovascular homeostasis and function; excessive or insufficient levels of autophagic flux can each contribute to heart disease pathogenesis. In this Review, we discuss the potential for targeting autophagy therapeutically and our vision for where this exciting biology may lead in the future. PMID:25654551

  4. Autophagy in cardiovascular biology.

    PubMed

    Lavandero, Sergio; Chiong, Mario; Rothermel, Beverly A; Hill, Joseph A

    2015-01-01

    Cardiovascular disease is the leading cause of death worldwide. As such, there is great interest in identifying novel mechanisms that govern the cardiovascular response to disease-related stress. First described in failing hearts, autophagy within the cardiovascular system has been widely characterized in cardiomyocytes, cardiac fibroblasts, endothelial cells, vascular smooth muscle cells, and macrophages. In all cases, a window of optimal autophagic activity appears to be critical to the maintenance of cardiovascular homeostasis and function; excessive or insufficient levels of autophagic flux can each contribute to heart disease pathogenesis. In this Review, we discuss the potential for targeting autophagy therapeutically and our vision for where this exciting biology may lead in the future.

  5. Emerging role of neurotensin in regulation of the cardiovascular system.

    PubMed

    Osadchii, Oleg E

    2015-09-01

    There is increasing evidence in support of an important role played by neurotensin (NT), a tridecapeptide originally found in bovine hypothalamus, in regulation of cardiovascular system. Elevated systemic levels of NT may contribute to pathogenesis of acute circulatory disoders, and predict the risk for cardiovascular morbidity and mortality in population-based studies. Within cardiovascular system, NT-containing neural fibers are found in close contact with atrial and ventricular cardiac myocytes, cardiac conduction system, intracardiac ganglia, as well as coronary vessels in humans and various animal species. The density of NT-immunoreactive innervation is reduced in cardiac disease. NT produces a variety of cardiovascular actions including effects on heart rate, myocardial contractility, systemic blood pressure, coronary vascular tone, venous smooth muscle tone, and regional blood flow in gastrointestinal tract, cutaneous and adipose tissue. NT could trigger cardiovascular reflexes by stimulating primary visceral afferents synaptically connected with preganglionic sympathetic neurons at the spinal cord. Structural determinants of biological activity of NT reside primarily in the C-terminal portion of its molecule which is responsible for receptor activation. NT effects are mediated via activation of NT receptors, or produced indirectly via stimulation of release of various endogenous neuromodulators/neurotransmitters such as histamine, catecholamines and prostaglandins. Three subtypes of NT receptor (NTS1, NTS2 and NTS3) have been shown to be expressed in the myocardium. NTS1, a high-affinity NT binding site coupled to phospholipase C-inositoltrisphosphate transduction pathway, is thought to mediate NT-induced cardiovascular responses.

  6. Traditional games resulted in post-exercise hypotension and a lower cardiovascular response to the cold pressor test in healthy children.

    PubMed

    Rauber, Suliane B; Boullosa, Daniel A; Carvalho, Ferdinando O; de Moraes, José F V N; de Sousa, Ioranny R C; Simões, Herbert G; Campbell, Carmen S G

    2014-01-01

    The present study aimed to verify if blood pressure (BP) reactivity could be reduced through a previous single session of active playing when compared to sedentary leisure. Sixteen pre-pubertal healthy children participated in this study. After familiarization with procedures and anthropometric evaluation, participants performed three sessions in randomized order: (1) 30 min of traditional Brazilian games (PLAY); (2) 30 min of video game playing (DDR); and (3) 30 min of watching TV (TV). Each session lasted 80 min, being 10 min of rest; 30 min of intervention activity; and 40 min of recovery. After recovery, the Cold Pressor Test (CPT) was used for the assessment of acute cardiovascular reactivity. BP was recorded at 30 s and 1 min during the CPT. Analysis of variance showed post-exercise hypotension (PEH) only after PLAY, and that systolic and diastolic BP were significantly increased in all conditions during CPT. However, the magnitude of the CPT-induced BP response was significantly less in PLAY compared to DDR and TV. The PEH observed during recovery and the reduced BP response to CPT following playing traditional games may be due its higher cardiovascular and metabolic demand as was indicated by the increased heart rate, oxygen consumption, and BP. It was concluded that BP reactivity to stress may be reduced through a previous single session of traditional games and that PEH was recorded only after this exercise form. This benefit indicates a potential role of playing strategies for cardiovascular health in childhood. PMID:25009506

  7. Evaluating the hemodynamical response of a cardiovascular system under support of a continuous flow left ventricular assist device via numerical modeling and simulations.

    PubMed

    Bozkurt, Selim; Safak, Koray K

    2013-01-01

    Dilated cardiomyopathy is the most common type of the heart failure which can be characterized by impaired ventricular contractility. Mechanical circulatory support devices were introduced into practice for the heart failure patients to bridge the time between the decision to transplant and the actual transplantation which is not sufficient due to the state of donor organ supply. In this study, the hemodynamic response of a cardiovascular system that includes a dilated cardiomyopathic heart under support of a newly developed continuous flow left ventricular assist device--Heart Turcica Axial--was evaluated employing computer simulations. For the evaluation, a numerical model which describes the pressure-flow rate relations of Heart Turcica Axial, a cardiovascular system model describing the healthy and pathological hemodynamics, and a baroreflex model regulating the heart rate were used. Heart Turcica Axial was operated between 8000 rpm and 11,000 rpm speeds with 1000 rpm increments for assessing the pump performance and response of the cardiovascular system. The results also give an insight about the range of the possible operating speeds of Heart Turcica Axial in a clinical application. Based on the findings, operating speed of Heart Turcica Axial should be between 10,000 rpm and 11,000 rpm.

  8. Proteomic Analysis of Erythritol-Producing Yarrowia lipolytica from Glycerol in Response to Osmotic Pressure.

    PubMed

    Yang, Li-Bo; Dai, Xiao-Meng; Zheng, Zhi-Yong; Zhu, Li; Zhan, Xiao-Bei; Lin, Chi-Chung

    2015-07-01

    Osmotic pressure is a critical factor for erythritol production with osmophilic yeast. Protein expression patterns of an erythritol-producing yeast, Yarrowia lipolytica, were analyzed to identify differentially-expressed proteins in response to osmotic pressure. In order to analyze intracellular protein levels quantitatively, two-dimensional gel electrophoresis was performed to separate and visualize the differential expression of the intracellular proteins extracted from Y. lipolytica cultured under low (3.17 osmol/kg) and high (4.21 osmol/kg) osmotic pressures. Proteomic analyses allowed identification of 54 differentially-expressed proteins among the proteins distributed in the range of pI 3-10 and 14.4-97.4 kDa molecular mass between the osmotic stress conditions. Remarkably, the main proteins were involved in the pathway of energy, metabolism, cell rescue, and stress response. The expression of such enzymes related to protein and nucleotide biosynthesis was inhibited drastically, reflecting the growth arrest of Y. lipolytica under hyperosmotic stress. The improvement of erythritol production under high osmotic stress was due to the significant induction of a range of crucial enzymes related to polyols biosynthesis, such as transketolase and triosephosphate isomerase, and the osmotic stress responsive proteins like pyridoxine-4-dehydrogenase and the AKRs family. The polyols biosynthesis was really related to an osmotic response and a protection mechanism against hyperosmotic stress in Y. lipolytica. Additionally, the high osmotic stress could also induce other cell stress responses as with heat shock and oxidation stress responses, and these responsive proteins, such as the HSPs family, catalase T, and superoxide dismutase, also had drastically increased expression levels under hyperosmotic pressure.

  9. Proteomic Analysis of Erythritol-Producing Yarrowia lipolytica from Glycerol in Response to Osmotic Pressure.

    PubMed

    Yang, Li-Bo; Dai, Xiao-Meng; Zheng, Zhi-Yong; Zhu, Li; Zhan, Xiao-Bei; Lin, Chi-Chung

    2015-07-01

    Osmotic pressure is a critical factor for erythritol production with osmophilic yeast. Protein expression patterns of an erythritol-producing yeast, Yarrowia lipolytica, were analyzed to identify differentially-expressed proteins in response to osmotic pressure. In order to analyze intracellular protein levels quantitatively, two-dimensional gel electrophoresis was performed to separate and visualize the differential expression of the intracellular proteins extracted from Y. lipolytica cultured under low (3.17 osmol/kg) and high (4.21 osmol/kg) osmotic pressures. Proteomic analyses allowed identification of 54 differentially-expressed proteins among the proteins distributed in the range of pI 3-10 and 14.4-97.4 kDa molecular mass between the osmotic stress conditions. Remarkably, the main proteins were involved in the pathway of energy, metabolism, cell rescue, and stress response. The expression of such enzymes related to protein and nucleotide biosynthesis was inhibited drastically, reflecting the growth arrest of Y. lipolytica under hyperosmotic stress. The improvement of erythritol production under high osmotic stress was due to the significant induction of a range of crucial enzymes related to polyols biosynthesis, such as transketolase and triosephosphate isomerase, and the osmotic stress responsive proteins like pyridoxine-4-dehydrogenase and the AKRs family. The polyols biosynthesis was really related to an osmotic response and a protection mechanism against hyperosmotic stress in Y. lipolytica. Additionally, the high osmotic stress could also induce other cell stress responses as with heat shock and oxidation stress responses, and these responsive proteins, such as the HSPs family, catalase T, and superoxide dismutase, also had drastically increased expression levels under hyperosmotic pressure. PMID:25737116

  10. [Biological responses of a Streptomyces strain producing-Nikkomycin to space flight].

    PubMed

    Luo, A; Gao, C; Song, Y; Tan, H; Liu, Z

    1998-12-01

    In order to see biological responses to the production of Nikkomycins in general and Nikkomycin X and Z in particular by space conditions, Streptomyces ansochromogenus, a Nikkomycins-producing strain, was carried onboard a satellite for 15 d in 1996. Several strains were isolated from the treated sample and found that the productivity of Nikkomycins in all was increased by 13-18 percent, and the proportion of Nikkomycin X and Z increased correspondingly. Besides, some biological properties of the isolated strains varied markedly.

  11. Investigation of protein expression profiles of erythritol-producing Candida magnoliae in response to glucose perturbation.

    PubMed

    Kim, Hyo Jin; Lee, Hyeong-Rho; Kim, Chang Sup; Jin, Yong-Su; Seo, Jin-Ho

    2013-08-15

    Protein expression patterns of an erythritol-producing yeast, Candida magnoliae, were analyzed to identify differentially expressed proteins in response to glucose perturbation. Specifically, wild type C. magnoliae was grown under high and low glucose conditions and the cells were harvested at both mid-exponential and erythritol production phases for proteomic studies. In order to analyze intracellular protein abundances from the harvested cells quantitatively, total intracellular proteins were extracted and applied to two-dimensional gel electrophoresis for separation and visualization of individual proteins. Among the proteins distributed in the range of pI 4-7 and molecular weight 29-97kDa, five osmo-responsive proteins were drastically changed in response to glucose perturbation. Hsp60 (Heat-shock protein 60), transaldolase and NADH:quinone oxidoreductase were down-regulated under the high glucose condition and Bro1 (BCK1-like Resistance to Osmotic shock) and Eno1 (enolase1) were up-regulated. These proteins are directly or indirectly related with cellular stress response. Importantly, protein expression patterns of Hsp60, Bro1 and Eno1 were strongly correlated with previous studies identifying the proteins perturbed by osmotic stress for other organisms including Saccharomyces cerevisiae.

  12. Investigation of Responsiveness to Thyrotropin-Releasing Hormone in Growth Hormone-Producing Pituitary Adenomas

    PubMed Central

    Chin, Sang Ouk; Hwang, You-Cheol; Jeong, In-Kyung; Oh, Seungjoon

    2013-01-01

    Objective. The aim of this study was to investigate how the paradoxical response of GH secretion to TRH changes according to tumor volumes. Methods. Patients with newly diagnosed acromegaly were classified as either TRH responders or nonresponders according to the results of a TRH stimulation test (TST), and their clinical characteristics were compared according to responsiveness to TRH and tumor volumes. Results. A total of 41 acromegalic patients who underwent the TST were included in this study. Between TRH responders and nonresponders, basal GH, IGF-I levels, peak GH levels, and tumor volume were not significantly different, but the between-group difference of GH levels remained near significant over the entire TST time. ΔGHmax-min during the TST were significantly different according to the responsiveness to TRH. Peak GH levels and ΔGHmax-min during the TST showed significantly positive correlations with tumor volume with higher levels in macroadenomas than in microadenomas. GH levels over the entire TST time also remained significantly higher in macroadenomas than in microadenomas. Conclusion. Our data demonstrated that the paradoxical response of GH secretion to TRH in GH-producing pituitary adenomas was not inversely correlated with tumor volumes. PMID:24348552

  13. A Functional Polymorphism in the 5HTR2C Gene Associated with Stress Responses Also Predicts Incident Cardiovascular Events

    PubMed Central

    Brummett, Beverly H.; Babyak, Michael A.; Jiang, Rong; Shah, Svati H.; Becker, Richard C.; Haynes, Carol; Chryst-Ladd, Megan; Craig, Damian M.; Hauser, Elizabeth R.; Siegler, Ilene C.; Kuhn, Cynthia M.; Singh, Abanish; Williams, Redford B.

    2013-01-01

    Previously we have shown that a functional nonsynonymous single nucleotide polymorphism (rs6318) of the 5HTR2C gene located on the X-chromosome is associated with hypothalamic-pituitary-adrenal axis response to a stress recall task, and with endophenotypes associated with cardiovascular disease (CVD). These findings suggest that individuals carrying the rs6318 Ser23 C allele will be at higher risk for CVD compared to Cys23 G allele carriers. The present study examined allelic variation in rs6318 as a predictor of coronary artery disease (CAD) severity and a composite endpoint of all-cause mortality or myocardial infarction (MI) among Caucasian participants consecutively recruited through the cardiac catheterization laboratory at Duke University Hospital (Durham, NC) as part of the CATHGEN biorepository. Study population consisted of 6,126 Caucasian participants (4,036 [65.9%] males and 2,090 [34.1%] females). A total of 1,769 events occurred (1,544 deaths and 225 MIs; median follow-up time =  5.3 years, interquartile range  = 3.3–8.2). Unadjusted Cox time-to-event regression models showed, compared to Cys23 G carriers, males hemizygous for Ser23 C and females homozygous for Ser23C were at increased risk for the composite endpoint of all-cause death or MI: Hazard Ratio (HR)  = 1.47, 95% confidence interval (CI)  = 1.17, 1.84, p  = .0008. Adjusting for age, rs6318 genotype was not related to body mass index, diabetes, hypertension, dyslipidemia, smoking history, number of diseased coronary arteries, or left ventricular ejection fraction in either males or females. After adjustment for these covariates the estimate for the two Ser23 C groups was modestly attenuated, but remained statistically significant: HR  = 1.38, 95% CI = 1.10, 1.73, p = .005. These findings suggest that this functional polymorphism of the 5HTR2C gene is associated with increased risk for CVD mortality and morbidity, but this association is apparently not

  14. Subchronic toxicity and cardiovascular responses in spontaneously hypertensive rats after exposure to multiwalled carbon nanotubes by intratracheal instillation.

    PubMed

    Chen, Rui; Zhang, Lili; Ge, Cuicui; Tseng, Michael T; Bai, Ru; Qu, Ying; Beer, Christiane; Autrup, Herman; Chen, Chunying

    2015-03-16

    The tremendous demand of the market for carbon nanotubes has led to their massive production that presents an increasing risk through occupational exposure. Lung deposition of carbon nanotubes is known to cause acute localized pulmonary adverse effects. However, systemic cardiovascular damages associated with acute pulmonary lesion have not been thoroughly addressed. Four kinds of multiwalled carbon nanotubes (MWCNTs) with different lengths and/or iron contents were used to explore the potential subchronic toxicological effects in spontaneously hypertensive (SH) rats and normotensive control Wistar-Kyoto (WKY) rats after intratracheal instillation. MWCNTs penetrated the lung blood-gas barrier and accumulated in the liver, kidneys, and spleen but not in the heart and aorta of SH rats. The pulmonary toxicity and cardiovascular effects were assessed at 7 and 30 days postexposure. Compared to the WKY rats, transient influences on blood pressure and up to 30 days persistent decrease in the heart rate of SH rats were found by electrocardiogram monitoring. The subchronic toxicity, especially the sustained inflammation of the pulmonary and cardiovascular system, was revealed at days 7 and 30 in both SH and WKY rat models. Histopathological results showed obvious morphological lesions in abdominal arteries of SH rats 30 days after exposure. Our results suggest that more attention should be paid to the long-term toxic effects of MWCNTs, and particularly, occupationally exposed workers with preexisting cardiovascular diseases should be monitored more thoroughly.

  15. Acute and delayed effects of intermittant ozone on cardiovascular and thermoregulatory responses of young and aged rats

    EPA Science Inventory

    Ozone (03) is associated with cardiovascular and respiratory diseases. The aged population is considered to be more sensitive to air pollutants but relatively few studies have demonstrated increased susceptibility in animal models of aging. To study the acute and delayed physiolo...

  16. Producer responsibility for e-waste management: key issues for consideration - learning from the Swiss experience.

    PubMed

    Khetriwal, Deepali Sinha; Kraeuchi, Philipp; Widmer, Rolf

    2009-01-01

    E-waste, a relatively recent addition to the waste stream in the form of discarded electronic and electric equipment, is getting increasing attention from policy makers as the quantity being generated is rising rapidly. One of the most promising policy options to address this issue is to extend the producers responsibility for their products beyond the point of sale, until end-of-product-life. This paper briefly introduces the concept of extended producer responsibility (EPR) and its applicability in the area of the end-of-life management of electronic and electrical equipment (EEE). It then examines the decade-long experience of Switzerland in using EPR to manage its e-waste, elaborating on the experience of the Swiss system in overcoming specific issues, and finally wrapping up with a synopsis of the lessons for policy makers. We consider each issue as an enquiry of questions confronting a policy maker and the choices that may present themselves. The five issues discussed are: (i) the challenges in getting an EPR based system started; (ii) securing financing to ensure a self-sustaining and smooth functioning system; (iii) organising a logistics network for the take back and collection of the e-waste; (iv) ensuring compliance of the various actors involved; and finally (v) reducing the threat of monopolistic practices.

  17. A comparison of the inflammatory response produced by commercial eugenol and purified eugenol.

    PubMed

    Webb, J G; Bussell, N E

    1981-09-01

    Eugenol "purified" by HPLC20 was compared to commercial USP eugenol to determine if any difference exists between the inflammatory response caused by each. Mixtures of each eugenol with zinc oxide were also compared. Each material was injected subcutaneously beneath the abdominal skin of 40 Walter Reed white rats. Ten animals were sacrificed at four different dates, and the degree of necrosis and inflammation was compared. The purified eugenol caused less necrosis and inflammation at all times than did the commercial eugenol. The purified ZOE mixture produced less necrosis and inflammation than the commercial ZOE mixture at each sacrifice date. The two mixtures of ZOE and the two samples of eugenol produced roughly parallel amounts of inflammation, suggesting that the degree of inflammation of ZOE mixtures is strongly influenced by the amounts of free eugenol in the mixtures. This study suggests that the impurities in commercial eugenol do cause an increase in the inflammatory response in the rat system studied. This increase is most evident at day two and after day ten.

  18. Producer responsibility for e-waste management: key issues for consideration - learning from the Swiss experience.

    PubMed

    Khetriwal, Deepali Sinha; Kraeuchi, Philipp; Widmer, Rolf

    2009-01-01

    E-waste, a relatively recent addition to the waste stream in the form of discarded electronic and electric equipment, is getting increasing attention from policy makers as the quantity being generated is rising rapidly. One of the most promising policy options to address this issue is to extend the producers responsibility for their products beyond the point of sale, until end-of-product-life. This paper briefly introduces the concept of extended producer responsibility (EPR) and its applicability in the area of the end-of-life management of electronic and electrical equipment (EEE). It then examines the decade-long experience of Switzerland in using EPR to manage its e-waste, elaborating on the experience of the Swiss system in overcoming specific issues, and finally wrapping up with a synopsis of the lessons for policy makers. We consider each issue as an enquiry of questions confronting a policy maker and the choices that may present themselves. The five issues discussed are: (i) the challenges in getting an EPR based system started; (ii) securing financing to ensure a self-sustaining and smooth functioning system; (iii) organising a logistics network for the take back and collection of the e-waste; (iv) ensuring compliance of the various actors involved; and finally (v) reducing the threat of monopolistic practices. PMID:18162284

  19. Changes in cholesterol homeostasis and acute phase response link pulmonary exposure to multi-walled carbon nanotubes to risk of cardiovascular disease.

    PubMed

    Poulsen, Sarah S; Saber, Anne T; Mortensen, Alicja; Szarek, Józef; Wu, Dongmei; Williams, Andrew; Andersen, Ole; Jacobsen, Nicklas R; Yauk, Carole L; Wallin, Håkan; Halappanavar, Sabina; Vogel, Ulla

    2015-03-15

    Adverse lung effects following pulmonary exposure to multi-walled carbon nanotubes (MWCNTs) are well documented in rodents. However, systemic effects are less understood. Epidemiological studies have shown increased cardiovascular disease risk after pulmonary exposure to airborne particles, which has led to concerns that inhalation exposure to MWCNTs might pose similar risks. We analyzed parameters related to cardiovascular disease, including plasma acute phase response (APR) proteins and plasma lipids, in female C57BL/6 mice exposed to a single intratracheal instillation of 0, 18, 54 or 162μg/mouse of small, entangled (CNTSmall, 0.8±0.1μm long) or large, thick MWCNTs (CNTLarge, 4±0.4μm long). Liver tissues and plasma were harvested 1, 3 and 28days post-exposure. In addition, global hepatic gene expression, hepatic cholesterol content and liver histology were used to assess hepatic effects. The two MWCNTs induced similar systemic responses despite their different physicochemical properties. APR proteins SAA3 and haptoglobin, plasma total cholesterol and low-density/very low-density lipoprotein were significantly increased following exposure to either MWCNTs. Plasma SAA3 levels correlated strongly with pulmonary Saa3 levels. Analysis of global gene expression revealed perturbation of the same biological processes and pathways in liver, including the HMG-CoA reductase pathway. Both MWCNTs induced similar histological hepatic changes, with a tendency towards greater response following CNTLarge exposure. Overall, we show that pulmonary exposure to two different MWCNTs induces similar systemic and hepatic responses, including changes in plasma APR, lipid composition, hepatic gene expression and liver morphology. The results link pulmonary exposure to MWCNTs with risk of cardiovascular disease.

  20. Practicalities of individual producer responsibility under the WEEE directive: experiences in Germany.

    PubMed

    Rotter, Vera Susanne; Chancerel, Perrine; Schill, Wolf-Peter

    2011-09-01

    In theory, individual producer responsibility (IPR) creates incentives for 'design-for-recycling'. Yet in practice, implementing IPR is challenging, particularly if applied to waste electric and electronic equipment. This article discusses different options for implementing IPR schemes under German WEEE legislation. In addition, practical aspects of a German 'return share' brand sampling scheme are examined. Concerning 'new' WEEE put on the market after 13 August 2006, producers in Germany can choose between two different methods of calculating take-back obligations. These can be determined on the basis of 'return shares' or 'market shares'. While market shares are regularly monitored by a national clearing house, the 'return share' option requires sampling and sorting of WEEE. Herein it is shown that the specifics of the German WEEE take-back scheme require high sample sizes and multi-step test procedures to ensure a statistically sound sampling approach. Since the market share allocation continues to apply for historic waste, producers lack incentives for choosing the costly brand sampling option. However, even return share allocation might not imply a decisive step towards IPR, as it merely represents an alternative calculation of market shares. Yet the fundamental characteristics of the German take-back system remain unchanged: the same anonymous mix of WEEE goes to the same treatment operations.

  1. A gene responsible for prolyl-hydroxylation of moss-produced recombinant human erythropoietin.

    PubMed

    Parsons, Juliana; Altmann, Friedrich; Graf, Manuela; Stadlmann, Johannes; Reski, Ralf; Decker, Eva L

    2013-01-01

    Recombinant production of pharmaceutical proteins is crucial, not only for personalized medicine. While most biopharmaceuticals are currently produced in mammalian cell culture, plant-made pharmaceuticals gain momentum. Post-translational modifications in plants are similar to those in humans, however, existing differences may affect quality, safety and efficacy of the products. A frequent modification in higher eukaryotes is prolyl-4-hydroxylase (P4H)-catalysed prolyl-hydroxylation. P4H sequence recognition sites on target proteins differ between humans and plants leading to non-human posttranslational modifications of recombinant human proteins produced in plants. The resulting hydroxyprolines display the anchor for plant-specific O-glycosylation, which bears immunogenic potential for patients. Here we describe the identification of a plant gene responsible for non-human prolyl-hydroxylation of human erythropoietin (hEPO) recombinantly produced in plant (moss) bioreactors. Targeted ablation of this gene abolished undesired prolyl-hydroxylation of hEPO and thus paves the way for plant-made pharmaceuticals humanized via glyco-engineering in moss bioreactors.

  2. A plant-produced antigen elicits potent immune responses against West Nile virus in mice.

    PubMed

    He, Junyun; Peng, Li; Lai, Huafang; Hurtado, Jonathan; Stahnke, Jake; Chen, Qiang

    2014-01-01

    We described the rapid production of the domain III (DIII) of the envelope (E) protein in plants as a vaccine candidate for West Nile Virus (WNV). Using various combinations of vector modules of a deconstructed viral vector expression system, DIII was produced in three subcellular compartments in leaves of Nicotiana benthamiana by transient expression. DIII expressed at much higher levels when targeted to the endoplasmic reticulum (ER) than that targeted to the chloroplast or the cytosol, with accumulation level up to 73  μ g DIII per gram of leaf fresh weight within 4 days after infiltration. Plant ER-derived DIII was soluble and readily purified to > 95% homogeneity without the time-consuming process of denaturing and refolding. Further analysis revealed that plant-produced DIII was processed properly and demonstrated specific binding to an anti-DIII monoclonal antibody that recognizes a conformational epitope. Furthermore, subcutaneous immunization of mice with 5 and 25  μ g of purified DIII elicited a potent systemic response. This study provided the proof of principle for rapidly producing immunogenic vaccine candidates against WNV in plants with low cost and scalability. PMID:24804264

  3. Changes in cholesterol homeostasis and acute phase response link pulmonary exposure to multi-walled carbon nanotubes to risk of cardiovascular disease

    SciTech Connect

    Poulsen, Sarah S.; Saber, Anne T.; Mortensen, Alicja; Szarek, Józef; Wu, Dongmei; Williams, Andrew; Andersen, Ole; Jacobsen, Nicklas R.; Yauk, Carole L.; Wallin, Håkan; Halappanavar, Sabina; Vogel, Ulla

    2015-03-15

    Adverse lung effects following pulmonary exposure to multi-walled carbon nanotubes (MWCNTs) are well documented in rodents. However, systemic effects are less understood. Epidemiological studies have shown increased cardiovascular disease risk after pulmonary exposure to airborne particles, which has led to concerns that inhalation exposure to MWCNTs might pose similar risks. We analyzed parameters related to cardiovascular disease, including plasma acute phase response (APR) proteins and plasma lipids, in female C57BL/6 mice exposed to a single intratracheal instillation of 0, 18, 54 or 162 μg/mouse of small, entangled (CNT{sub Small}, 0.8 ± 0.1 μm long) or large, thick MWCNTs (CNT{sub Large}, 4 ± 0.4 μm long). Liver tissues and plasma were harvested 1, 3 and 28 days post-exposure. In addition, global hepatic gene expression, hepatic cholesterol content and liver histology were used to assess hepatic effects. The two MWCNTs induced similar systemic responses despite their different physicochemical properties. APR proteins SAA3 and haptoglobin, plasma total cholesterol and low-density/very low-density lipoprotein were significantly increased following exposure to either MWCNTs. Plasma SAA3 levels correlated strongly with pulmonary Saa3 levels. Analysis of global gene expression revealed perturbation of the same biological processes and pathways in liver, including the HMG-CoA reductase pathway. Both MWCNTs induced similar histological hepatic changes, with a tendency towards greater response following CNT{sub Large} exposure. Overall, we show that pulmonary exposure to two different MWCNTs induces similar systemic and hepatic responses, including changes in plasma APR, lipid composition, hepatic gene expression and liver morphology. The results link pulmonary exposure to MWCNTs with risk of cardiovascular disease. - Highlights: • Systemic and hepatic alterations were evaluated in female mice following MWCNT instillation. • Despite being physicochemically

  4. Modulations in oscillatory activity with amplitude asymmetry can produce cognitively relevant event-related responses

    PubMed Central

    van Dijk, Hanneke; van der Werf, Jurrian; Mazaheri, Ali; Medendorp, W. Pieter; Jensen, Ole

    2009-01-01

    Event-related responses and oscillatory activity are typically regarded as manifestations of different neural processes. Recent work has nevertheless revealed a mechanism by which slow event-related responses are created as a direct consequence of modulations in brain oscillations with nonsinusoidal properties. It remains unknown if this mechanism applies to cognitively relevant event-related responses. Here, we investigated whether sustained event-related fields (ERFs) measured during working memory maintenance can be explained by modulations in oscillatory power. In particular, we focused on contralateral delayed activity (CDA) typically observed in working memory tasks in which hemifield specific attention is manipulated. Using magnetoencephalography, we observed sustained posterior ERFs following the presentation of the memory target. These ERFs were systematically lateralized with respect to the hemisphere in which the target was presented. A strikingly similar pattern emerged for modulations in alpha (9–13 Hz) power. The alpha power and ERF lateralization were strongly correlated over subjects. Based on a mechanistic argument pertaining to the nonsinusoidal properties of the alpha activity, we conclude that the ERFs modulated by working memory are likely to be directly produced by the modulations in oscillatory alpha activity. Given that posterior alpha activity typically reflects disengagement, we conclude that the CDA is not attributable to an additive process reflecting memory maintenance per se but, rather, is a consequence of how attentional resources are allocated. PMID:20080773

  5. Advancing cardiovascular tissue engineering

    PubMed Central

    Truskey, George A.

    2016-01-01

    Cardiovascular tissue engineering offers the promise of biologically based repair of injured and damaged blood vessels, valves, and cardiac tissue. Major advances in cardiovascular tissue engineering over the past few years involve improved methods to promote the establishment and differentiation of induced pluripotent stem cells (iPSCs), scaffolds from decellularized tissue that may produce more highly differentiated tissues and advance clinical translation, improved methods to promote vascularization, and novel in vitro microphysiological systems to model normal and diseased tissue function. iPSC technology holds great promise, but robust methods are needed to further promote differentiation. Differentiation can be further enhanced with chemical, electrical, or mechanical stimuli. PMID:27303643

  6. Human short-latency ocular vergence responses produced by interocular velocity differences

    PubMed Central

    Sheliga, B. M.; Quaia, C.; FitzGibbon, E. J.; Cumming, B. G.

    2016-01-01

    We studied human short-latency vergence eye movements to a novel stimulus that produces interocular velocity differences without a changing disparity signal. Sinusoidal luminance gratings moved in opposite directions (left vs. right; up vs. down) in the two eyes. The grating seen by each eye underwent ¼-wavelength shifts with each image update. This arrangement eliminated changing disparity cues, since the phase difference between the eyes alternated between 0° and 180°. We nevertheless observed robust short-latency vergence responses (VRs), whose sign was consistent with the interocular velocity differences (IOVDs), indicating that the IOVD cue in isolation can evoke short-latency VRs. The IOVD cue was effective only when the images seen by the two eyes overlapped in space. We observed equally robust VRs for opposite horizontal motions (left in one eye, right in the other) and opposite vertical motions (up in one eye, down in the other). Whereas the former are naturally generated by objects moving in depth, the latter are not part of our normal experience. To our knowledge, this is the first demonstration of a behavioral consequence of vertical IOVD. This may reflect the fact that some neurons in area MT are sensitive to these motion signals (Czuba, Huk, Cormack, & Kohn, 2014). VRs were the strongest for spatial frequencies in the range of 0.35–1 c/°, much higher than the optimal spatial frequencies for evoking ocular-following responses observed during frontoparallel motion. This suggests that the two motion signals are detected by different neuronal populations. We also produced IOVD using moving uncorrelated one-dimensional white-noise stimuli. In this case the most effective stimuli have low speed, as predicted if the drive originates in neurons tuned to high spatial frequencies (Sheliga, Quaia, FitzGibbon, & Cumming, 2016). PMID:27548089

  7. Targeting brains, producing responsibilities: the use of neuroscience within British social policy.

    PubMed

    Broer, Tineke; Pickersgill, Martyn

    2015-05-01

    Concepts and findings 'translated' from neuroscientific research are finding their way into UK health and social policy discourse. Critical scholars have begun to analyse how policies tend to 'misuse' the neurosciences and, further, how these discourses produce unwarranted and individualizing effects, rooted in middle-class values and inducing guilt and anxiety. In this article, we extend such work while simultaneously departing from the normative assumptions implied in the concept of 'misuse'. Through a documentary analysis of UK policy reports focused on the early years, adolescence and older adults, we examine how these employ neuroscientific concepts and consequently (re)define responsibility. In the documents analysed, responsibility was produced in three different but intersecting ways: through a focus on optimisation, self-governance, and vulnerability. Our work thereby adds to social scientific examinations of neuroscience in society that show how neurobiological terms and concepts can be used to construct and support a particular imaginary of citizenship and the role of the state. Neuroscience may be leveraged by policy makers in ways that (potentially) reduce the target of their intervention to the soma, but do so in order to expand the outcome of the intervention to include the enhancement of society writ large. By attending as well to more critical engagements with neuroscience in policy documents, our analysis demonstrates the importance of being mindful of the limits to the deployment of a neurobiological idiom within policy settings. Accordingly, we contribute to increased empirical specificity concerning the impacts and translation of neuroscientific knowledge in contemporary society whilst refusing to take for granted the idea that the neurosciences necessarily have a dominant role (to play). PMID:25792340

  8. Human short-latency ocular vergence responses produced by interocular velocity differences.

    PubMed

    Sheliga, B M; Quaia, C; FitzGibbon, E J; Cumming, B G

    2016-08-01

    We studied human short-latency vergence eye movements to a novel stimulus that produces interocular velocity differences without a changing disparity signal. Sinusoidal luminance gratings moved in opposite directions (left vs. right; up vs. down) in the two eyes. The grating seen by each eye underwent ¼-wavelength shifts with each image update. This arrangement eliminated changing disparity cues, since the phase difference between the eyes alternated between 0° and 180°. We nevertheless observed robust short-latency vergence responses (VRs), whose sign was consistent with the interocular velocity differences (IOVDs), indicating that the IOVD cue in isolation can evoke short-latency VRs. The IOVD cue was effective only when the images seen by the two eyes overlapped in space. We observed equally robust VRs for opposite horizontal motions (left in one eye, right in the other) and opposite vertical motions (up in one eye, down in the other). Whereas the former are naturally generated by objects moving in depth, the latter are not part of our normal experience. To our knowledge, this is the first demonstration of a behavioral consequence of vertical IOVD. This may reflect the fact that some neurons in area MT are sensitive to these motion signals (Czuba, Huk, Cormack, & Kohn, 2014). VRs were the strongest for spatial frequencies in the range of 0.35-1 c/°, much higher than the optimal spatial frequencies for evoking ocular-following responses observed during frontoparallel motion. This suggests that the two motion signals are detected by different neuronal populations. We also produced IOVD using moving uncorrelated one-dimensional white-noise stimuli. In this case the most effective stimuli have low speed, as predicted if the drive originates in neurons tuned to high spatial frequencies (Sheliga, Quaia, FitzGibbon, & Cumming, 2016). PMID:27548089

  9. Targeting brains, producing responsibilities: the use of neuroscience within British social policy.

    PubMed

    Broer, Tineke; Pickersgill, Martyn

    2015-05-01

    Concepts and findings 'translated' from neuroscientific research are finding their way into UK health and social policy discourse. Critical scholars have begun to analyse how policies tend to 'misuse' the neurosciences and, further, how these discourses produce unwarranted and individualizing effects, rooted in middle-class values and inducing guilt and anxiety. In this article, we extend such work while simultaneously departing from the normative assumptions implied in the concept of 'misuse'. Through a documentary analysis of UK policy reports focused on the early years, adolescence and older adults, we examine how these employ neuroscientific concepts and consequently (re)define responsibility. In the documents analysed, responsibility was produced in three different but intersecting ways: through a focus on optimisation, self-governance, and vulnerability. Our work thereby adds to social scientific examinations of neuroscience in society that show how neurobiological terms and concepts can be used to construct and support a particular imaginary of citizenship and the role of the state. Neuroscience may be leveraged by policy makers in ways that (potentially) reduce the target of their intervention to the soma, but do so in order to expand the outcome of the intervention to include the enhancement of society writ large. By attending as well to more critical engagements with neuroscience in policy documents, our analysis demonstrates the importance of being mindful of the limits to the deployment of a neurobiological idiom within policy settings. Accordingly, we contribute to increased empirical specificity concerning the impacts and translation of neuroscientific knowledge in contemporary society whilst refusing to take for granted the idea that the neurosciences necessarily have a dominant role (to play).

  10. A long-term copper exposure on freshwater ecosystem using lotic mesocosms: Primary producer community responses.

    PubMed

    Roussel, Hélène; Ten-Hage, Loïc; Joachim, Sandrine; Le Cohu, René; Gauthier, Laury; Bonzom, Jean-Marc

    2007-02-28

    Copper is commonly used as an algicide and plant herbicide in the aquatic environment. Despite of its frequent application in rivers, ponds and lakes, few studies have been performed at the ecosystem level on primary producers' communities. A long-term lotic mesocosms study was carried on, in 20m long channels, under environmentally realistic concentrations of copper (0, 5, 25 and 75 microgL(-1)) delivered continuously for 18 months. Results showed significant effects at the 25 and 75 microgL(-1) copper treatment levels on the phytoplankton, periphyton and macrophyte community structure. Effects on biomass and abundance were dissimilar depending on the studied community. Phytoplankton showed no abundance variation with treatment, whereas periphyton had higher biomass and macrophytes had lower coverage at 25 and 75 microgL(-1). Taxa richness was significantly affected for all primary producers communities at 25 and 75 microgL(-1). Some taxa seemed to be sensitive to copper, i.e. Cocconeis spp., Epithemia sp., Gomphonema spp., Lemna minor, Nasturtium officinale and filamentous macroalgae. Other taxa appeared to be tolerant or facilitated by indirect effects, i.e. Leptolyngbya sp., Mougeotia sp., Nitzschia palea, Pseudanabaena sp. and Ulothrix sp. and therefore increased in the 25 and 75 microgL(-1) treatments. Important indirect factors influenced the community responses, such as trophic interactions like decrease of grazing pressure, competition for light and nutrients and temperature favouring blue-green algae development. After 18 months of copper exposure, the no observed effect concentration at community level (NOEC(community)) for primary producers was set up at 5 or 4mugL(-1), if we consider the average effective concentration, with a lowest observed effect concentration (LOEC(community)) at 25 or 20 microgL(-1) (AEC). PMID:17239970

  11. Angiotensin-I- and -III-mediated cardiovascular responses in the freshwater North American eel, Anguilla rostrata: effect of Phe8 deletion.

    PubMed

    Butler, D G; Oudit, G Y

    1995-02-01

    Cardiovascular responses to synthetic eel [Asn1, Val5, Gly9]-ANG-I, ANG-III (2-8), and ANG-I (1-7) were measured in conscious and resting freshwater North American eels. Indwelling Doppler flow probes were placed on the ventral and dorsal aortas, a pressure catheter in the lienomesenteric artery, and a peptide delivery catheter in the caudal vein. Twenty-five and 150 ng.kg-1 ANG-III increased baseline cardiac output (CO) (15.23 +/- 0.31 ml.min-1.kg-1; n = 5) by 23 and 47%, respectively, by increasing stroke volume (SV) but not heart rate (HR). ANG-I (150 ng.kg-1) also elevated CO (62%) by increasing both SV (44%) and HR (14%). Estimated branchial shunting (BS) was increased by 150 ng.kg-1 ANG-I and -III suggesting that more blood perfused the arteriovenous pathway in the gills. Dorsal aortic blood pressure (PDA) (3.08 +/- 0.12 kPa) was elevated by 150 ng.kg-1 ANG-I (67%) and -III (52%). Pressor responses temporally preceded the blood flow increases and there was a significant increase in systemic vascular resistance (RSYS) at the peak pressor responses. At the peak flow responses, increased CO was solely responsible for the increase in PDA; RSYS had returned to baseline values. Pressor responses to ANG-III decayed more rapidly (18.6 min) compared with those of ANG-I and -II (36 min). ANG-I (1-7) had no measurable effect on cardiovascular function indicating that the carboxyl-terminal 8-phenylalanine is an absolute requirement for the hormonal activity of angiotensin in fishes.

  12. Proteome Response of Tribolium castaneum Larvae to Bacillus thuringiensis Toxin Producing Strains

    PubMed Central

    Contreras, Estefanía; Rausell, Carolina; Real, M. Dolores

    2013-01-01

    Susceptibility of Tribolium castaneum (Tc) larvae was determined against spore-crystal mixtures of five coleopteran specific and one lepidopteran specific Bacillus thuringiensis Cry toxin producing strains and those containing the structurally unrelated Cry3Ba and Cry23Aa/Cry37Aa proteins were found toxic (LC50 values 13.53 and 6.30 µg spore-crystal mixture/µL flour disc, respectively). Using iTRAQ combined with LC-MS/MS allowed the discovery of seven novel differentially expressed proteins in early response of Tc larvae to the two active spore-crystal mixtures. Proteins showing a statistically significant change in treated larvae compared to non-intoxicated larvae fell into two major categories; up-regulated proteins were involved in host defense (odorant binding protein C12, apolipophorin-III and chemosensory protein 18) and down-regulated proteins were linked to metabolic pathways affecting larval metabolism and development (pyruvate dehydrogenase Eα subunit, cuticular protein, ribosomal protein L13a and apolipoprotein LI-II). Among increased proteins, Odorant binding protein C12 showed the highest change, 4-fold increase in both toxin treatments. The protein displayed amino acid sequence and structural homology to Tenebrio molitor 12 kDa hemolymph protein b precursor, a non-olfactory odorant binding protein. Analysis of mRNA expression and mortality assays in Odorant binding protein C12 silenced larvae were consistent with a general immune defense function of non-olfactory odorant binding proteins. Regarding down-regulated proteins, at the transcriptional level, pyruvate dehydrogenase and cuticular genes were decreased in Tc larvae exposed to the Cry3Ba producing strain compared to the Cry23Aa/Cry37Aa producing strain, which may contribute to the developmental arrest that we observed with larvae fed the Cry3Ba producing strain. Results demonstrated a distinct host transcriptional regulation depending upon the Cry toxin treatment. Knowledge on how insects

  13. Proteome response of Tribolium castaneum larvae to Bacillus thuringiensis toxin producing strains.

    PubMed

    Contreras, Estefanía; Rausell, Carolina; Real, M Dolores

    2013-01-01

    Susceptibility of Tribolium castaneum (Tc) larvae was determined against spore-crystal mixtures of five coleopteran specific and one lepidopteran specific Bacillus thuringiensis Cry toxin producing strains and those containing the structurally unrelated Cry3Ba and Cry23Aa/Cry37Aa proteins were found toxic (LC(50) values 13.53 and 6.30 µg spore-crystal mixture/µL flour disc, respectively). Using iTRAQ combined with LC-MS/MS allowed the discovery of seven novel differentially expressed proteins in early response of Tc larvae to the two active spore-crystal mixtures. Proteins showing a statistically significant change in treated larvae compared to non-intoxicated larvae fell into two major categories; up-regulated proteins were involved in host defense (odorant binding protein C12, apolipophorin-III and chemosensory protein 18) and down-regulated proteins were linked to metabolic pathways affecting larval metabolism and development (pyruvate dehydrogenase Eα subunit, cuticular protein, ribosomal protein L13a and apolipoprotein LI-II). Among increased proteins, Odorant binding protein C12 showed the highest change, 4-fold increase in both toxin treatments. The protein displayed amino acid sequence and structural homology to Tenebrio molitor 12 kDa hemolymph protein b precursor, a non-olfactory odorant binding protein. Analysis of mRNA expression and mortality assays in Odorant binding protein C12 silenced larvae were consistent with a general immune defense function of non-olfactory odorant binding proteins. Regarding down-regulated proteins, at the transcriptional level, pyruvate dehydrogenase and cuticular genes were decreased in Tc larvae exposed to the Cry3Ba producing strain compared to the Cry23Aa/Cry37Aa producing strain, which may contribute to the developmental arrest that we observed with larvae fed the Cry3Ba producing strain. Results demonstrated a distinct host transcriptional regulation depending upon the Cry toxin treatment. Knowledge on how insects

  14. Production response to corn silage produced from normal, brown midrib, or waxy corn hybrids.

    PubMed

    Barlow, J S; Bernard, J K; Mullis, N A

    2012-08-01

    The objective was to evaluate the nutrient intake and digestibility and milk production response of lactating dairy cows fed diets based on corn silage produced from 3 different types of corn hybrids. Experimental diets contained 36.4% of the dietary dry matter (DM) from corn silage produced from normal (Agratech 1021, AgraTech Seeds Inc., Atlanta, GA), brown midrib (BMR; Mycogen F2F797, Mycogen Seeds, Indianapolis, IN), or waxy (Master's Choice 590, Master's Choice Hybrids, Ullin, IL) hybrids. Thirty-six multiparous and primiparous Holstein cows (66 ± 22 d in milk, 41 ± 8 kg/d of milk) were used in an 11-wk completely randomized design trial during the fall of 2009. All cows were fed a diet containing normal corn silage during the first 2wk of the trial before being assigned to 1 of 3 treatments for the following 9 wk. Data collected during the first 2 wk were used as a covariate in the statistical analysis. No difference was observed in dry matter intake (DMI) among treatments, which averaged 22.6 kg/d. Milk yield was higher for cows fed BMR (37.6 kg/d) compared with waxy (35.2 kg/d) but was similar to that of cows fed control (36.2 kg/d). Milk fat percentage tended to be lower for cows fed control (3.28%) compared with those fed BMR (3.60%) or waxy (3.55%) corn silage. Milk protein percentage tended to be lower for cows fed control (2.79%) compared with waxy (2.89%) but similar to that of those fed BMR (2.85%). No differences were observed in yield of milk components. Energy-corrected milk (ECM) yield and dairy efficiency (ECM:DMI) did not differ among treatments. Cows fed BMR tended to gain more body weight compared with those fed control and waxy. Results of this trial are consistent with previous reports in which cows fed diets based on corn silage produced from BMR hybrids have higher milk yield compared with those fed other hybrids. Corn silage produced from the waxy hybrid supported a similar yield of ECM because of higher milk components, but milk yield

  15. Favorable neuromuscular and cardiovascular responses to 7 days of exercise with an eccentric overload in elderly women.

    PubMed

    Hortobágyi, T; DeVita, P

    2000-08-01

    The metabolic, cardiovascular, and neural cost of eccentric muscle contraction is less than that of concentric contraction, but the strength and neural adaptations in eccentric contractions are significantly greater following resistive exercise. We thus compared the short-term effects of exercise with an eccentric overload (n = 10) with those of exercise with a standard load distribution (n = 10) in ostensibly healthy sedentary elderly women (mean age 71.4). Subjects were tested for concentric and eccentric three-repetition maximum, maximal isokinetic eccentric and concentric and isometric force, and associated electromyographic activity of selected thigh muscles before and after 7 consecutive days of exercise training of the left knee extensors. The exercise program was designed so that the total weight lifted was similar between eccentric overload and standard groups, but the eccentric overload group exercised with an approximately 50% greater eccentric load. Control subjects did not exercise (n = 10). There was a 46% increase in the total weight lifted over 7 days. When all strength measures were combined, the eccentric overload group's strength gains were 1.8-fold greater than those of the standard group, and the cardiovascular stress in terms of heart rate, mean arterial pressure, rate pressure product, and perceived exertion was significantly lower. The increases in muscle strength were achieved by increased muscle activation, but the strength gains were independent of the changes in antagonistic muscle coactivity. Because the strength gains occurred after a short period of exercise at a relatively low intensity and cardiovascular demand, the prescription of exercise with an eccentric overload appears suitable for elders, individuals deconditioned as a result of an injury, and the chronically diseased.

  16. Position-Dependent Cardiovascular Response and Time-Motion Analysis During Training Drills and Friendly Matches in Elite Male Basketball Players.

    PubMed

    Torres-Ronda, Lorena; Ric, Angel; Llabres-Torres, Ivan; de Las Heras, Bernat; Schelling I Del Alcazar, Xavi

    2016-01-01

    The purpose of this study was to measure differences in the cardiovascular workload (heart rate [HR]) and time-motion demands between positional groups, during numerous basketball training drills, and compare the results with in-game competition demands. A convenience sample of 14 top-level professional basketball players from the same club (Spanish First Division, ACB) participated in the study. A total of 146 basketball exercises per player (performed over an 8-week period in 32 team training sessions throughout the competitive season) and 7 friendly matches (FM) played during the preparatory phase were analyzed. The results reveal that HRavg and HRpeak were the highest in FM (158 ± 10; 198 ± 9 b · min(-1), respectively). Time-motion analysis showed 1v1 to be the most demanding drill (53 ± 8 and 46 ± 12 movements per minute for full and half court, respectively). During FM, players performed 33 ± 7 movements per minute. Positional differences exist for both HR and time-motion demands, ranging from moderate to very large for all basketball drills compared with FM. Constraints such as number of players, court size, work-to-rest ratios, and coach intervention are key factors influencing cardiovascular responses and time-motion demands during basketball training sessions. These results demonstrate that systematic monitoring of the physical demands and physiological responses during training and competition can inform and potentially improve coaching strategy, basketball-specific training drills, and ultimately, match performance.

  17. Position-Dependent Cardiovascular Response and Time-Motion Analysis During Training Drills and Friendly Matches in Elite Male Basketball Players.

    PubMed

    Torres-Ronda, Lorena; Ric, Angel; Llabres-Torres, Ivan; de Las Heras, Bernat; Schelling I Del Alcazar, Xavi

    2016-01-01

    The purpose of this study was to measure differences in the cardiovascular workload (heart rate [HR]) and time-motion demands between positional groups, during numerous basketball training drills, and compare the results with in-game competition demands. A convenience sample of 14 top-level professional basketball players from the same club (Spanish First Division, ACB) participated in the study. A total of 146 basketball exercises per player (performed over an 8-week period in 32 team training sessions throughout the competitive season) and 7 friendly matches (FM) played during the preparatory phase were analyzed. The results reveal that HRavg and HRpeak were the highest in FM (158 ± 10; 198 ± 9 b · min(-1), respectively). Time-motion analysis showed 1v1 to be the most demanding drill (53 ± 8 and 46 ± 12 movements per minute for full and half court, respectively). During FM, players performed 33 ± 7 movements per minute. Positional differences exist for both HR and time-motion demands, ranging from moderate to very large for all basketball drills compared with FM. Constraints such as number of players, court size, work-to-rest ratios, and coach intervention are key factors influencing cardiovascular responses and time-motion demands during basketball training sessions. These results demonstrate that systematic monitoring of the physical demands and physiological responses during training and competition can inform and potentially improve coaching strategy, basketball-specific training drills, and ultimately, match performance. PMID:26284807

  18. Whole grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-response meta-analysis of prospective studies

    PubMed Central

    Keum, NaNa; Giovannucci, Edward; Fadnes, Lars T; Boffetta, Paolo; Greenwood, Darren C; Tonstad, Serena; Vatten, Lars J; Riboli, Elio; Norat, Teresa

    2016-01-01

    Objective To quantify the dose-response relation between consumption of whole grain and specific types of grains and the risk of cardiovascular disease, total cancer, and all cause and cause specific mortality. Data sources PubMed and Embase searched up to 3 April 2016. Study selection Prospective studies reporting adjusted relative risk estimates for the association between intake of whole grains or specific types of grains and cardiovascular disease, total cancer, all cause or cause specific mortality. Data synthesis Summary relative risks and 95% confidence intervals calculated with a random effects model. Results 45 studies (64 publications) were included. The summary relative risks per 90 g/day increase in whole grain intake (90 g is equivalent to three servings—for example, two slices of bread and one bowl of cereal or one and a half pieces of pita bread made from whole grains) was 0.81 (95% confidence interval 0.75 to 0.87; I2=9%, n=7 studies) for coronary heart disease, 0.88 (0.75 to 1.03; I2=56%, n=6) for stroke, and 0.78 (0.73 to 0.85; I2=40%, n=10) for cardiovascular disease, with similar results when studies were stratified by whether the outcome was incidence or mortality. The relative risks for morality were 0.85 (0.80 to 0.91; I2=37%, n=6) for total cancer, 0.83 (0.77 to 0.90; I2=83%, n=11) for all causes, 0.78 (0.70 to 0.87; I2=0%, n=4) for respiratory disease, 0.49 (0.23 to 1.05; I2=85%, n=4) for diabetes, 0.74 (0.56 to 0.96; I2=0%, n=3) for infectious diseases, 1.15 (0.66 to 2.02; I2=79%, n=2) for diseases of the nervous system disease, and 0.78 (0.75 to 0.82; I2=0%, n=5) for all non-cardiovascular, non-cancer causes. Reductions in risk were observed up to an intake of 210-225 g/day (seven to seven and a half servings per day) for most of the outcomes. Intakes of specific types of whole grains including whole grain bread, whole grain breakfast cereals, and added bran, as well as total bread and total breakfast cereals were also associated

  19. Cardiovascular and sympathetic neural responses to handgrip and cold pressor stimuli in humans before, during and after spaceflight

    NASA Technical Reports Server (NTRS)

    Fu, Qi; Levine, Benjamin D.; Pawelczyk, James A.; Ertl, Andrew C.; Diedrich, Andre; Cox, James F.; Zuckerman, Julie H.; Ray, Chester A.; Smith, Michael L.; Iwase, Satoshi; Saito, Mitsuru; Sugiyama, Yoshiki; Mano, Tadaaki; Zhang, Rong; Iwasaki, Kenichi; Lane, Lynda D.; Buckey, Jay C Jr; Cooke, William H.; Robertson, Rose Marie; Baisch, Friedhelm J.; Blomqvist, C. Gunnar; Eckberg, Dwain L.; Robertson, David; Biaggioni, Italo

    2002-01-01

    Astronauts returning to Earth have reduced orthostatic tolerance and exercise capacity. Alterations in autonomic nervous system and neuromuscular function after spaceflight might contribute to this problem. In this study, we tested the hypothesis that exposure to microgravity impairs autonomic neural control of sympathetic outflow in response to peripheral afferent stimulation produced by handgrip and a cold pressor test in humans. We studied five astronauts approximately 72 and 23 days before, and on landing day after the 16 day Neurolab (STS-90) space shuttle mission, and four of the astronauts during flight (day 12 or 13). Heart rate, arterial pressure and peroneal muscle sympathetic nerve activity (MSNA) were recorded before and during static handgrip sustained to fatigue at 40 % of maximum voluntary contraction, followed by 2 min of circulatory arrest pre-, in- and post-flight. The cold pressor test was applied only before (five astronauts) and during flight (day 12 or 13, four astronauts). Mean (+/- S.E.M.) baseline heart rates and arterial pressures were similar among pre-, in- and post-flight measurements. At the same relative fatiguing force, the peak systolic pressure and mean arterial pressure during static handgrip were not different before, during and after spaceflight. The peak diastolic pressure tended to be higher post- than pre-flight (112 +/- 6 vs. 99 +/- 5 mmHg, P = 0.088). Contraction-induced rises in heart rate were similar pre-, in- and post-flight. MSNA was higher post-flight in all subjects before static handgrip (26 +/- 4 post- vs. 15 +/- 4 bursts min(-1) pre-flight, P = 0.017). Contraction-evoked peak MSNA responses were not different before, during, and after spaceflight (41 +/- 4, 38 +/- 5 and 46 +/- 6 bursts min(-1), all P > 0.05). MSNA during post-handgrip circulatory arrest was higher post- than pre- or in-flight (41 +/- 1 vs. 33 +/- 3 and 30 +/- 5 bursts min(-1), P = 0.038 and 0.036). Similarly, responses of MSNA and blood pressure

  20. Activation of GABAA or 5HT1A receptors in the raphé pallidus abolish the cardiovascular responses to exogenous stress in conscious rats.

    PubMed

    Pham-Le, Nhut Minh; Cockburn, Chelsea; Nowell, Katherine; Brown, Justin

    2011-11-25

    Dysfunction in serotonin (5HT) neurotransmission in the brainstem of infants may disrupt protective responses to stress and increase the risk for Sudden Infant Death Syndrome (SIDS). The raphé pallidus (NRP) and other brainstem nuclei are rich in 5HT and are thought to mediate stress responses, including increases in blood pressure (BP) and heart rate (HR). Determining how 5HT neurotransmission in the brainstem mediates responses to stress will help to explain how dysfunction in neurotransmission could increase the risk of SIDS. It was hypothesized that alterations in neurotransmission in the NRP, specifically activation of the 5HT(1A) receptor subtype, would block cardiovascular responses to various types of exogenous stress. Using aseptic techniques, male Sprague-Dawley rats were instrumented with radiotelemetry probes which enabled non-invasive measurement of BP and HR. An indwelling microinjection cannula was also stereotaxically implanted into the NRP for injection of drugs that altered local 5HT neurotransmission. Following a one week recovery period, rats were microinjected with either muscimol (GABA(A) receptor agonist), 8-OH-DPAT (agonist to the inhibitory 5HT(1A) receptor), or a vehicle control (artificial cerebral spinal fluid; ACSF) immediately prior to exposure to one of three stressors: handling, air jet, or restraint. Physical handling and restraint of the animal were designed to elicit a mild and a maximal stress response respectively; while an air jet directed at the rat's face was used to provoke a psychological stress that did not require physical contact. All three stressors elicited similar and significant elevations in HR and BP following ACSF that persisted for at least 15 min with BP and HR elevated by ∼14.0 mmHg and ∼56.3 bpm respectively. The similarity in the stress responses suggest even mild handling of a rat elicits a maximal sympathoexcitatory response. The stress response was abolished following 8-OH-DPAT or muscimol

  1. Gender differences and the relationships of perceived background stress and psychological distress with cardiovascular responses to laboratory stressors.

    PubMed

    Allen, Michael T; Bocek, Christine M; Burch, Ashley E

    2011-09-01

    The primary aim of this study was to evaluate the relationships of perceived background stress and self-reported psychological distress on cardiovascular reactivity during acute laboratory stressors. The Perceived Stress Scale (PSS) was used as the measure of perceived background stress, and the General Health Questionnaire (GHQ) was used as the measure of psychological distress. A secondary aim was to examine whether background stress and psychological distress affected the susceptibility to induction of a negative mood using music. Heart rate (HR) and blood pressure (BP) were measured in 149 female and male college students at rest and during a stressful mental arithmetic (MA) task and a mood induction procedure. Higher scores on the GHQ were associated with lower systolic BP reactivity during the MA task by all participants. Higher scores on the PSS and GHQ were also associated with lower diastolic BP and HR reactivity, but only in females. Thus, higher self-reports of background stress and psychological distress tended to result in blunted reactivity to an acute laboratory challenge. Higher levels of background stress and psychological distress were not associated with greater susceptibility to a negative mood induction. This study adds to the growing literature indicating that potentially negative health outcomes may be associated with diminished cardiovascular reactivity under certain conditions.

  2. Human cardiovascular and vestibular responses in long minutes and low +Gz loading by a short arm centrifuge

    NASA Astrophysics Data System (ADS)

    Yajima, K.; Miyamoto, A.; Ito, M.; Maru, R.; Maeda, T.; Sanada, E.; Nakazato, T.; Saiki, C.; Yamaguchi, Y.; Igarashi, M.; Matsumoto, S.

    1.4 G, 1.7 G, and 2.0 G of +Gz and 60 minutes centrifugation was adopted to 20 healthy male subjects using 1.8 m radius centrifuge equipped to Nihon University School of Medicine. G was applied from lower G, considering G training effect for the subjects. Effects on performance decline and side effects of such a short-arm centrifugation were especially observed in the experiments, because this size of centrifuge could be used in space station in future for a strong countermeasure of cardiovascular deconditioning, demineralization from bone, etc. G training effect was observed same as higher and rapid G acceleration in fighter pilot. Subjects suffered from many types of discomfort; such as sensation of heaviness of diaphragm, cold sweat, nausea, irritable feeling, arrhythmia, tachycardia, rapid decrease of blood pressure, which sometimes caused interruption of G load. As 2.0 G and 60 minutes centrifugation seemed very tough load to the subjects, there should be necessary some G suit or other countermeasure, if we apply a higher G and/or longer G duration. Performance decline due to the load commonly continued for 1 hour or so. Side effects were observed in relation to neuro-vestibular, cardio-vascular, and autonomic nervous system.

  3. Carbon nanotubes reinforced chitosan films: mechanical properties and cell response of a novel biomaterial for cardiovascular tissue engineering.

    PubMed

    Kroustalli, A; Zisimopoulou, A E; Koch, S; Rongen, L; Deligianni, D; Diamantouros, S; Athanassiou, G; Kokozidou, M; Mavrilas, D; Jockenhoevel, S

    2013-12-01

    Carbon nanotubes have been proposed as fillers to reinforce polymeric biomaterials for the strengthening of their structural integrity to achieve better biomechanical properties. In this study, a new polymeric composite material was introduced by incorporating various low concentrations of multiwalled carbon nanotubes (MWCNTs) into chitosan (CS), aiming at achieving a novel composite biomaterial with superior mechanical and biological properties compared to neat CS, in order to be used in cardiovascular tissue engineering applications. Both mechanical and biological characteristics in contact with the two relevant cell types (endothelial cells and vascular myofibroblasts) were studied. Regarding the mechanical behavior of MWCNT reinforced CS (MWCNT/CS), 5 and 10 % concentrations of MWCNTs enhanced the mechanical behavior of CS, with that of 5 % exhibiting a superior mechanical strength compared to 10 % concentration and neat CS. Regarding biological properties, MWCNT/CS best supported proliferation of endothelial and myofibroblast cells, MWCNTs and MWCNT/CS caused no apoptosis and were not toxic of the examined cell types. Conclusively, the new material could be suitable for tissue engineering (TE) and particularly for cardiovascular TE applications.

  4. Involvement of hindbrain and peripheral prostanoids in gastric motor and cardiovascular responses to delta-9-tetrahydrocannabinol in the rat.

    PubMed

    Krowicki, Z K

    2012-12-01

    We previously reported that delta-9-tetrahydrocannabinol (delta-9-THC), the primary psychoactive constituent of Cannabis sativa, inhibited gastric motor activity and evoked bradycardia and hypotension upon its parenteral administration in the rat. As prostanoids are important mediators of the actions of cannabinoids, we hypothesized that the inhibitory gastric motor and cardiovascular effects of delta-9-THC could depend on cyclooxygenase (COX) activation in the hindbrain and/or in the periphery. To test this hypothesis, vehicle or delta-9-THC (0.2 mg/kg, i.v.) were administered before and 15-min after the COX inhibitor tolmetin (50 mg/kg, i.v.) or 15 min after topical application of tolmetin to the surface of the dorsal medulla (0.5 mg/rat) in chloralose-anesthetized rats. Delta-9-THC-evoked gastric motor inhibition and bradycardia were abolished by parenteral and were attenuated by hindbrain administration of tolmetin. Moreover, administration of delta-9-THC after parenteral tolmetin evoked marked and long-lasting hypertension. We concluded that the inhibitory gastric motor and cardiovascular effects of systemically administered delta-9-THC depend on the hindbrain and peripheral activation of COX. PMID:23388474

  5. Gender differences and the relationships of perceived background stress and psychological distress with cardiovascular responses to laboratory stressors.

    PubMed

    Allen, Michael T; Bocek, Christine M; Burch, Ashley E

    2011-09-01

    The primary aim of this study was to evaluate the relationships of perceived background stress and self-reported psychological distress on cardiovascular reactivity during acute laboratory stressors. The Perceived Stress Scale (PSS) was used as the measure of perceived background stress, and the General Health Questionnaire (GHQ) was used as the measure of psychological distress. A secondary aim was to examine whether background stress and psychological distress affected the susceptibility to induction of a negative mood using music. Heart rate (HR) and blood pressure (BP) were measured in 149 female and male college students at rest and during a stressful mental arithmetic (MA) task and a mood induction procedure. Higher scores on the GHQ were associated with lower systolic BP reactivity during the MA task by all participants. Higher scores on the PSS and GHQ were also associated with lower diastolic BP and HR reactivity, but only in females. Thus, higher self-reports of background stress and psychological distress tended to result in blunted reactivity to an acute laboratory challenge. Higher levels of background stress and psychological distress were not associated with greater susceptibility to a negative mood induction. This study adds to the growing literature indicating that potentially negative health outcomes may be associated with diminished cardiovascular reactivity under certain conditions. PMID:21729723

  6. Dufulin Activates HrBP1 to Produce Antiviral Responses in Tobacco

    PubMed Central

    Chen, Zhuo; Zeng, Mengjiao; Song, Baoan; Hou, Chengrui; Hu, Deyu; Li, Xiangyang; Wang, Zhenchao; Fan, Huitao; Bi, Liang; Liu, Jiaju; Yu, Dandan; Jin, Linhong; Yang, Song

    2012-01-01

    Background Dufulin is a new antiviral agent that is highly effective against plant viruses and acts by activating systemic acquired resistance (SAR) in plants. In recent years, it has been used widely to prevent and control tobacco and rice viral diseases in China. However, its targets and mechanism of action are still poorly understood. Methodology/Principal Findings Here, differential in-gel electrophoresis (DIGE) and classical two-dimensional electrophoresis (2-DE) techniques were combined with mass spectrometry (MS) to identify the target of Dufulin. More than 40 proteins were found to be differentially expressed (≥1.5 fold or ≤1.5 fold) upon Dufulin treatment in Nicotiana tabacum K326. Based on annotations in the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, these proteins were found to be related to disease resistance. Directed acyclic graph (DAG) analysis of the various pathways demonstrated harpin binding protein-1 (HrBP1) as the target of action of Dufulin. Additionally, western blotting, semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), and real time PCR analyses were also conducted to identify the specific mechanism of action of Dufulin. Our results show that activation of HrBP1 triggers the salicylic acid (SA) signaling pathway and thereby produces antiviral responses in the plant host. A protective assay based on lesion counting further confirmed the antiviral activity of Dufulin. Conclusion This study identified HrBP1 as a target protein of Dufulin and that Dufulin can activate the SA signaling pathway to induce host plants to generate antiviral responses. PMID:22662252

  7. The immune response of juvenile Atlantic cod (Gadus morhua L.) to chronic exposure to produced water.

    PubMed

    Pérez-Casanova, Juan C; Hamoutene, Dounia; Samuelson, Stephanie; Burt, Kimberly; King, Thomas L; Lee, Kenneth

    2010-07-01

    Produced water (PW) is the main discharge from the offshore oil industry and contains oil-derived compounds such as poly-aromatic hydrocarbons, phenols, alkylphenols, and heavy metals. Studies suggest that PW discharges may affect the biota over larger areas from the oil drilling sites at sea than originally predicted. We investigated the effects of chronic exposure to PW on some aspects of juvenile Atlantic cod immunity, stress response and growth by intermittently exposing fish to 0, 100 or 200 ppm of PW for 22 weeks. No significant effects of PW were observed on growth, hepatosomatic index, condition factor or plasma cortisol. The respiratory burst (RB) of circulating leukocytes was significantly elevated in the 100 ppm group only, while the RB of head-kidney leukocytes was significantly decreased in both the 100 and 200 ppm groups. Significant up-regulation of the mRNA expression of beta-2-microglobulin, immunoglobulin-M light chain and interleukins-1beta and -8 was observed in the 200 ppm group, while the down-regulation of interferon stimulated gene 15 was obvious for both the 100 and 200 ppm groups. The results suggest that chronic exposure to environmentally relevant concentrations of PW causes modulations of the immune system of juvenile Atlantic cod with most immune parameters being stimulated, potentially resulting in an energetic cost that may be detrimental to the fish.

  8. The immune response of juvenile Atlantic cod (Gadus morhua L.) to chronic exposure to produced water.

    PubMed

    Pérez-Casanova, Juan C; Hamoutene, Dounia; Samuelson, Stephanie; Burt, Kimberly; King, Thomas L; Lee, Kenneth

    2010-07-01

    Produced water (PW) is the main discharge from the offshore oil industry and contains oil-derived compounds such as poly-aromatic hydrocarbons, phenols, alkylphenols, and heavy metals. Studies suggest that PW discharges may affect the biota over larger areas from the oil drilling sites at sea than originally predicted. We investigated the effects of chronic exposure to PW on some aspects of juvenile Atlantic cod immunity, stress response and growth by intermittently exposing fish to 0, 100 or 200 ppm of PW for 22 weeks. No significant effects of PW were observed on growth, hepatosomatic index, condition factor or plasma cortisol. The respiratory burst (RB) of circulating leukocytes was significantly elevated in the 100 ppm group only, while the RB of head-kidney leukocytes was significantly decreased in both the 100 and 200 ppm groups. Significant up-regulation of the mRNA expression of beta-2-microglobulin, immunoglobulin-M light chain and interleukins-1beta and -8 was observed in the 200 ppm group, while the down-regulation of interferon stimulated gene 15 was obvious for both the 100 and 200 ppm groups. The results suggest that chronic exposure to environmentally relevant concentrations of PW causes modulations of the immune system of juvenile Atlantic cod with most immune parameters being stimulated, potentially resulting in an energetic cost that may be detrimental to the fish. PMID:20338632

  9. Heterogeneous responses of personalised high intensity interval training on type 2 diabetes mellitus and cardiovascular disease risk in young healthy adults.

    PubMed

    Higgins, Timothy P; Baker, Matthew D; Evans, Shelley-Ann; Adams, Rachel A; Cobbold, Christian

    2015-01-01

    Hypertension, decreased glucose tolerance, adverse lipid profiles and low physical activity levels are associated with increased type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD) risk. High intensity interval training (HIIT), a low volume, reduced time, high intensity programme, may be a useful alternative to current government guidelines which specify a minimum of 150 minutes of physical activity per week. We describe a personalised programme of high intensity exercise which provides significant improvements in CVD risk markers. Healthy volunteers undertook 6 weeks of HIIT. T2DM and CVD risk predictors including glucose tolerance, VO2max, blood pressure (BP), and lipids were measured before and after HIIT. HIIT training was associated with beneficial changes in a range of predictors of blood flow and cardiovascular risk. There was a heterogeneous response to HIIT, with some subjects responding with favourable changes and others being non-responders to HIIT. In responders, HIIT was associated with a statistically significant (p = 0.023) increase in VO2max, from 45.4 (38.4,52.5) to 56.9 (51.2,65.7) (median (interquartile range)(ml/min/kg)). In responders HIIT resulted in a decrease in systolic BP from 127 (126,129) to 116 (106,122) (mmHg) with p = 0.026 and a decrease is diastolic blood pressure from 72 (69,74) to 57 (56,66) with p = 0.026. There was also some evidence of a beneficial change in blood lipid and glucose concentrations with HIIT. In conclusion, personalised HIIT has potential as an intervention to improve blood flow and cardiovascular health.

  10. Ozone and cardiovascular injury.

    PubMed

    Srebot, Vera; Gianicolo, Emilio A L; Rainaldi, Giuseppe; Trivella, Maria Giovanna; Sicari, Rosa

    2009-06-24

    Air pollution is increasingly recognized as an important and modifiable determinant of cardiovascular diseases in urban communities. The potential detrimental effects are both acute and chronic having a strong impact on morbidity and mortality. The acute exposure to pollutants has been linked to adverse cardiovascular events such as myocardial infarction, heart failure and life-threatening arrhythmias. The long-terms effects are related to the lifetime risk of death from cardiac causes. The WHO estimates that air pollution is responsible for 3 million premature deaths each year. The evidence supporting these data is very strong nonetheless, epidemiologic and observational data have the main limitation of imprecise measurements. Moreover, the lack of clinical experimental models makes it difficult to demonstrate the individual risk. The other limitation is related to the lack of a clear mechanism explaining the effects of pollution on cardiovascular mortality. In the present review we will explore the epidemiological, clinical and experimental evidence of the effects of ozone on cardiovascular diseases. The pathophysiologic consequences of air pollutant exposures have been extensively investigated in pulmonary systems, and it is clear that some of the major components of air pollution (e.g. ozone and particulate matter) can initiate and exacerbate lung disease in humans 1. It is possible that pulmonary oxidant stress mediated by particulate matter and/or ozone (O3) exposure can result in downstream perturbations in the cardiovasculature, as the pulmonary and cardiovascular systems are intricately associated, and it is well documented that specific environmental toxins (such as tobacco smoke 2) introduced through the lungs can initiate and/or accelerate cardiovascular disease development. Indeed, several epidemiologic studies have proved that there is an association between PM and O3 and the increased incidence of cardiovascular morbidity and mortality 3. Most of the

  11. Preliminary Results from the Joint Russian and US Field Test: Measurement of Sensorimotor and Cardiovascular Responses Immediately Following Landing of the Soyuz Spacecraft

    NASA Technical Reports Server (NTRS)

    Reschke, M. F.; Kozlovskaya, I. B.; Tomilovskaya, E. S.; Bloomberg, J. J.; Platts, S. H.; Rukavishnikov, I. V.; Fomina, E. V.; Stenger, M. B.; Lee, S. M. C.; Wood, S. J.; Mulavara, A. P.; Fieveson, A. H.; Cerisano, J. M.; Kofman, I. S.; Fisher, E. A.

    2013-01-01

    Ongoing collaborative research efforts between NASA's Neuroscience and Cardiovascular Laboratories, and the Institute of Biomedical Problems' (IBMP) Sensory-Motor and Countermeasures Laboratories have been measuring functional sensorimotor, cardiovascular and strength responses following bed rest, dry immersion, short duration (Space Shuttle) and long duration (Mir and International Space Station) space flights. While the unloading paradigms associated with dry immersion and bed rest have do serve as acceptable flight analogs, testing of crew responses following the long duration flights does not begin until a minimum of 24 hours after landing. As a result it is not possible to estimate the nonlinear trend of the early (<24 hr) recovery process nor is it possible to accurately assess the full impact of the decrements associated with long duration flight. To overcome these limitations both the Russian and U.S. sides have implemented testing at the time of landing and before the flight crews have left the landing site. By joint agreement this research effort has been identified as the functional Field Test (FT). For practical reasons the FT has been divided into two phases: the full FT and a preliminary pilot version (PFT) of the FT that is reduced in both length and scope. The primary goal of this research is to determine functional abilities in long duration space flight crews beginning as soon after landing as possible (< 2 hr) with one to three immediate follow-up measurements on the day of landing. This goal has both sensorimotor and cardiovascular elements including an evaluation of NASA's new anti-orthostatic compression garment as compared with the Russian Kentavr garment. Functional sensorimotor measurements will include, but are not limited to, assessment of hand/eye coordination, ability to egress from a seated position, walk normally without falling, measurement of dynamic visual acuity, ability to discriminate different forces generated with both the

  12. Programmed cell death in barley aleurone cells is not directly stimulated by reactive oxygen species produced in response to gibberellin.

    PubMed

    Aoki, Nozomi; Ishibashi, Yushi; Kai, Kyohei; Tomokiyo, Reisa; Yuasa, Takashi; Iwaya-Inoue, Mari

    2014-05-01

    The cereal aleurone layer is a secretory tissue that produces enzymes to hydrolyze the starchy endosperm during germination. We recently demonstrated that reactive oxygen species (ROS), produced in response to gibberellins (GA), promoted GAMyb expression, which induces α-amylase expression in barley aleurone cells. On the other hand, ROS levels increase during programmed cell death (PCD) in barley aleurone cells, and GAMyb is involved in PCD of these cells. In this study, we investigated whether the ROS produced in response to GA regulate PCD directly by using mutants of Slender1 (SLN1), a DELLA protein that negatively regulates GA signaling. The wild-type, the sln1c mutant (which exhibits gibberellin-type signaling even in the absence of GA), and the Sln1d mutant (which is gibberellin-insensitive with respect to α-amylase production) all produced ROS in response to GA, suggesting that ROS production in aleurone cells in response to GA is independent of GA signaling through this DELLA protein. Exogenous GA promoted PCD in the wild-type. PCD in sln1c was induced even without exogenous GA (and so without induction of ROS), whereas PCD in Sln1d was not induced in the presence of exogenous GA, even though the ROS content increased significantly in response to GA. These results suggest that PCD in barley aleurone cells is not directly stimulated by ROS produced in response to GA but is regulated by GA signaling through DELLA protein.

  13. Effects of moxibusting Point Kuan-Yuan on cardiovascular and renal responses to histamine-induced shock.

    PubMed

    Chen, H C

    1987-01-01

    Moxibustion of the Point Kuan-Yuan is said by some Chinese herb doctors to have "anti-shock" effect. Using histamine-induced shock in anesthetized dogs, we studied the cardiovascular and renal effects of moxibusting Point Kuan-Yuan. We found that it significantly increased cardiac output, total peripheral resistance, and mean blood pressure but it did not significantly increase heart rate. Moxibustion also significantly increased renal plasma flow, glomerular filtration rate, urine flow, and Na+ Cl-K+ excretions. Whether moxibusting Kuan-Yuan may be useful as an adjunct in treating clinical shocks deserves more extensive studies in well-controlled clinical situations. It may also be helpful in clinical situations in which elevation of the sympathetic activity may be beneficial.

  14. Testosterone Dose-Response Relationships With Cardiovascular Risk Markers in Androgen-Deficient Women: A Randomized, Placebo-Controlled Trial

    PubMed Central

    Tang, Elizabeth; Aakil, Adam; Anderson, Stephan; Jara, Hernan; Davda, Maithili; Stroh, Helene; Travison, Thomas G.; Bhasin, Shalender; Basaria, Shehzad

    2014-01-01

    Objective: To determine dose-dependent effects of T administration on cardiovascular risk markers in women with low T levels. Methods: Seventy-one hysterectomized women with or without oophorectomy with total T < 31 ng/dL and/or free T < 3.5 pg/mL received a standardized transdermal estradiol regimen during the 12-week run-in period and were then randomized to receive weekly im injections of placebo or 3-, 6.25-, 12.5-, or 25-mg T enanthate for 24 weeks. Total and free T levels were measured by liquid chromatography-tandem mass spectrometry and equilibrium dialysis, respectively. Insulin resistance and inflammatory markers were measured at baseline and 24 weeks. In a subset of women, magnetic resonance imaging of the abdomen was performed to quantify abdominal fat volume. Results: Fifty-nine women who completed the 24-week intervention were included in the final analysis. The five groups were similar at baseline. Mean on-treatment nadir total T concentrations were 14, 79, 105, 130, and 232 ng/dL in the placebo group and the 3-, 6.25-, 12.5-, and 25-mg groups, respectively. No significant changes in fasting glucose, fasting insulin, homeostatic model assessment of insulin resistance, high sensitivity C-reactive protein, adiponectin, blood pressure, and heart rate were observed at any T dose when compared to placebo. Similarly, no dose- or concentration-dependent changes were observed in abdominal fat on magnetic resonance imaging. Conclusion: Short-term T administration over a wide range of doses for 24 weeks in women with low T levels was not associated with worsening of cardiovascular risk markers. PMID:24712568

  15. Individual Differences in the Temporal Profile of Cardiovascular Responses to Head Down Tilt and Orthostatic Stress with and Without Fluid Loading

    NASA Technical Reports Server (NTRS)

    Cowings, Patricia; Toscano, William; Kanis, Dionisios; Gebreyesus, Fiyore

    2013-01-01

    Susceptibility of healthy astronauts to orthostatic hypotension and presyncope is exacerbated upon return from spaceflight. Hypo-volemia is suspected to play an important role in cardiovascular deconditioning following exposure to spaceflight, which may lead to increased peripheral resistance, attenuated arterial baroreflex, and changes in cardiac function. The effect of altered gravity during space flight and planetary transition on human cardiovascular function is of critical importance to maintenance of astronaut health and safety. A promising countermeasure for post-flight orthostatic intolerance is fluid loading used to restore loss fluid volume by giving crew salt tablets and water prior to re-entry. Eight men and eight women will be tested during two, 6-hour exposures to 6o HDT: 1) fluid loading, 2) no fluid loading. Before and immediately after each HDT, subjects will perform a stand test to assess their orthostatic tolerance. Physiological measures (e.g., ECG, blood pressure, peripheral blood volume) will be continuously monitored while echocardiography measures are recorded at 30-minute intervals during HDT and stand tests. Preliminary results (N=4) clearly show individual differences in responses to this countermeasure and the time course of physiological changes induced by HDT.

  16. Indian poverty and cardiovascular disease.

    PubMed

    Ramaraj, Radhakrishnan; Alpert, Joseph Stephen

    2008-07-01

    Cardiovascular disease is among the world's leading causes of death, and nearly 80% of deaths occur in developing countries. Cardiovascular disease is becoming a major health problem in India, where life expectancy has increased with decreases in infectious disease and childhood mortality. It is well established that this population experiences coronary artery disease at a younger age than other populations. With infectious diseases still endemic, noncommunicable diseases are a lower priority for the governments of developing countries. There is a clear progression to degenerative and lifestyle-related diseases such as cardiovascular disease as a result of current social and economic change. The lack of a public response to the increasing risk for cardiovascular disease thus far is due mostly to a perception among policy makers and the public that cardiovascular disease is largely a problem of the urban rich. In conclusion, this review addresses the imminent threats and ways to tackle the epidemic in India. PMID:18572045

  17. Light limitation in a stream ecosystem: Responses by primary producers and consumers

    SciTech Connect

    Hill, W.R.; Ryon, M.G.; Schilling, E.M.

    1995-06-01

    Heavy shade presents serious challenges for primary producers and food-limited herbivores in forest streams. This study examines the response of periphyton and grazing snails (Elimia clavaeformis) to summer shade in White Oak Creek (WOC) in a Tennessee deciduous forest. Three experiments were performed: (1) in situ manipulation of light and snail density to test the effects of light limitation and grazing; (2) construction of photosynthesis-irradiance (P-I) curves to test for shade adaptation by periphyton; and (3) measurements of snail growth vs. irradiance. In the first experiment, light and snail densities were manipulated in a 2 x 2 factorial design. Snails at normal densities cropped periphyton biomass to low levels regardless of light regime, but periphyton productivity was higher at the open sites where snails grew faster and accumulated more lipid. Snail growth and lipid accumulation were strongly affected by intraspecific competition in both light regimes. In the second experiment, photosynthesis-irradiance curves for periphyton from shaded and open sites illustrated considerable shade adaptation: shaded periphyton was 2 times more efficient at low irradiance than with periphyton from open sites. Despite the greater efficiency of shaded periphyton at low irradiance, integrated primary production estimated with photosynthetic models was 4 times greater in the open because shade adaptation provided only partial compensation for the shade. In the third experiment, in situ snail growth again increased with decreasing shade. Bottom-up effects of light limitation were propagated very strongly in WOC, where the vertebrate fauna is dominated by a grazer that appears to escape top-down control. 68 refs., 4 figs., 3 tabs.

  18. The response of primary producers to nutrient enrichment in a shallow estuary

    USGS Publications Warehouse

    Kinney, E.H.; Roman, C.T.

    1998-01-01

    Shallow coastal systems worldwide are exhibiting increased algal growth in response to nutrient enrichment. This study evaluates primary production patterns in an estuarine system (Bass Harbor Marsh, Maine) receiving low levels of anthropogenic nitrogen. Biomass, areal coverage and in situ oxygen production of green macroalgae, Ruppia maritima, and phytoplankton were measured over a growing season to determine net ecosystem production. Macroalgae and Ruppia exhibited strong seasonal biomass curves with early summer peaks; however, peak biomass of macroalgae (150 g dwt m-2) was substantially greater than Ruppia (33 g dwt m-2). Phytoplankton biomass, measured as chlorophyll a, was low (<1 ug l-1) early in the season and peaked (11 ug l-1) following a mid-summer decline in macroalgal biomass, suggesting a competitive interaction with macroalgae. Instantaneous net production rates varied over the growing season for all three primary producers. Ruppia net production ranged from near zero to 3.7 mg C g dwt-1 h-1, with higher rates during summer and much of the seasonal variability explained by temperature. Macroalgal (0.88 - 5.0 mg C g dwt-1 h-1) and phytoplankton (0 - 28 mg C m-3 h-1) net production did not exhibit any clear seasonal signal. Net primary production calculated on an areal basis demonstrated macroalgae's dominance in the lower basin of Bass Harbor Marsh, with peak summer rates (400 mg C m-2 h-1) greatly exceeding maximum rates for both Ruppia (70 mg C m-2 h-1) and phytoplankton (12 mg C m-2 h-1). When compared to other New England estuarine sites with short residence times, nutrient loading and peak green macroalgal biomass in Bass Harbor Marsh is relatively low; however, the strong dominance of opportunistic green macroalgae is a pattern that is characteristic of shallow coastal systems undergoing eutrophication.

  19. Response of primary producers to nutrient enrichment in a shallow estuary

    USGS Publications Warehouse

    Kinney, E.H.; Roman, C.T.

    1998-01-01

    Shallow coastal systems worldwide are exhibiting increased algal growth in response to nutrient enrichment. This study evaluates primary production patterns in an estuarine system (Bass Harbor Marsh, ME, USA) receiving low levels of anthropogenic nitrogen. Biomass, areal coverage and in situ oxygen production of green macroalgae, Ruppia Maritima, and Phytoplankton were measured over a growing season to determine net ecosystem production. Macroalgae and R. maritima exhibited seasonal biomass curves with early summer peaks; however, peak biomass of macroalgae [150 g dry weight (wt) m-2] was substantially greater that R. maritima (33 g dry wt m-2) Phytoplankton biomass, measured as chlorophyll a, was low (<1 ??g 1-1) early in the season and peaked (11 ??g 1-1) following a mid-summer decline in macroalgal biomass, suggesting a competitive interaction with macroalgae. Instantaneous net production rates varied over the growing season for all 3 primary producers. R. maritima net production ranged from near zero to 2.7 mg C g-1 dry wt h-1, with higher rates during summer and much of the seasonal variability explained by temperature. Macroalgal (0.88 to 5.0 mg C g-1 dry wt h-1) and phytoplankton (0 to 28 mg C m-3 h-1) net production did not exhibit any clear seasonal signal. Net primary production calculated on an areal basis demonstrated macroalgae's dominance in the lower basin of Bass Harbor Marsh, with peak summer rates (400 mg C m-2 h-1) greatly exceeding maximum rates for both R maritima (70 mg C m-2h-1) and phytoplankton (12 mg C m-2 h-1). When compared to other New England estuarine sites with short residence times, nutrient loading and peak green macroalgal biomass in Bass Harbor Marsh are relatively low; however, the strong dominance of opportunistic green macroalgae is a pattern that is characteristic of shallow coastal systems undergoing eutrophication.

  20. Responses of organic and inorganic materials to intense EUV radiation from laser-produced plasmas

    NASA Astrophysics Data System (ADS)

    Makimura, Tetsuya; Torii, Shuichi; Nakamura, Daisuke; Takahashi, Akihiko; Okada, Tatsuo; Niino, Hiroyuki; Murakami, Kouichi

    2013-05-01

    We have investigated responses of polymers to EUV radiation from laser-produced plasmas beyond ablation thresholds and micromachining. We concentrated on fabricate precise 3D micro-structures of PDMS, PMMA, acrylic block copolymers (BCP), and silica. The micromachining technique can be applied to three-dimensional micro-fluidic and bio-medical devices. The EUV processing is a promising to realize a practical micromachining technique. In the present work, we used two EUV radiation sources; (a) Wide band EUV light in a range of 10{300 eV was generated by irradiation of Ta targets with Nd:YAG laser light at 500 mJ/pulse. (b) Narrow band EUV light at 11 and 13 nm was generated by irradiation of solid Xe and Sn targets, respectively, with pulsed TEA CO2 laser light. The generated EUV light was condensed onto the materials at high power density beyond the ablation thresholds, using ellipsoidal mirrors. We found that through-holes with a diameter of one micrometer an be fabricated in PMMA and PDMS sheets with thicknesses of 4-10 micrometers, at 250 and 230 nm/shot, respectively. The effective ablation of PMMA sheets can be applied to a LIGA-like process for fabricating micro-structures of metals for micro- and nano-molds. PDMS sheets are ablated if it is irradiated with EUV light beyond a distinct threshold power density, while PDMS surfaces were modified at lower power densities. Furthermore, BCP sheets were ablated to have 1-micrometer structures. Thus, we have developed a practical technique for micromachining of PMMA, PDMS and BCP sheets in a micrometer scale.

  1. Changes in and Stability of Cardiovascular Responses to Behavorial Stress: Results from a Four-Year Longitudinal Study of Children.

    ERIC Educational Resources Information Center

    Matthews, Karen A.; And Others

    1990-01-01

    Blood pressure and heart rate responses during serial subtraction, mirror image tracing, and isometric exercise tasks were longitudinally reliable for all measures except heart rate responses during isometric exercise. Systolic blood pressure responses to all tasks increased with age for boys, but not for girls. (RH)

  2. Neuropeptides in cardiovascular control.

    PubMed

    Ganong, W F

    1984-12-01

    Neuropeptides can affect cardiovascular function in various ways. They can serve as cotransmitters in the autonomic nervous system; for example, vasoactive intestinal peptide (VIP) is released with acetylcholine and neuropeptide Y with norepinephrine from postganglionic neurons. Substance P and, presumably, other peptides can can affect cardiovascular function when released near blood vessels by antidromically conducted impulses in branches of stimulated sensory neurons. In the central nervous system, many different neuropeptides appear to function as transmitters or contransmittes in the neural pathways that regulate the cardiovascular system. In addition neuropeptides such as vasopressin and angiotensin II also circulate as hormones that are involved in cardiovascular control. Large doses of exogenous vasopressin are required to increase blood pressure in normal animals because the increase in total peripheral resistance produced by the hormones is accompanied by a decrease in cardiac output. However, studies with synthetic peptides that selectively antagonize the vasopressor action of vasopressin indicate that circulating vasopressin is important in maintaining blood pressure when animals are hypovolemic due to dehydration, haemorrhage or adrenocortical insufficiency. VIP dilates blood vessels and stimulates renin secretion by a direct action on the juxtaglomerular cells. Renin secretion is stimulated when the concentration of VIP in plasma exceeds 75 pmol/litre, and higher values are seen in a number of conditions. Neostigmine, a drug which increases the secretion of endogenous VIP, also increases renin secretion, and this increase is not blocked by renal denervation or propranolol. Thus, VIP may be a physiologically significant renin stimulating hormone.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Nrf2 and cardiovascular defense.

    PubMed

    Howden, Reuben

    2013-01-01

    The cardiovascular system is susceptible to a group of diseases that are responsible for a larger proportion of morbidity and mortality than any other disease. Many cardiovascular diseases are associated with a failure of defenses against oxidative stress-induced cellular damage and/or death, leading to organ dysfunction. The pleiotropic transcription factor, nuclear factor-erythroid (NF-E) 2-related factor 2 (Nrf2), regulates the expression of antioxidant enzymes and proteins through the antioxidant response element. Nrf2 is an important component in antioxidant defenses in cardiovascular diseases such as atherosclerosis, hypertension, and heart failure. Nrf2 is also involved in protection against oxidant stress during the processes of ischemia-reperfusion injury and aging. However, evidence suggests that Nrf2 activity does not always lead to a positive outcome and may accelerate the pathogenesis of some cardiovascular diseases (e.g., atherosclerosis). The precise conditions under which Nrf2 acts to attenuate or stimulate cardiovascular disease processes are unclear. Further studies on the cellular environments related to cardiovascular diseases that influence Nrf2 pathways are required before Nrf2 can be considered a therapeutic target for the treatment of cardiovascular diseases.

  4. Cardiovascular and nervous system changes during meditation

    PubMed Central

    Steinhubl, Steven R.; Wineinger, Nathan E.; Patel, Sheila; Boeldt, Debra L.; Mackellar, Geoffrey; Porter, Valencia; Redmond, Jacob T.; Muse, Evan D.; Nicholson, Laura; Chopra, Deepak; Topol, Eric J.

    2015-01-01

    Background: A number of benefits have been described for the long-term practice of meditation, yet little is known regarding the immediate neurological and cardiovascular responses to meditation. Wireless sensor technology allows, for the first time, multi-parameter and quantitative monitoring of an individual's responses during meditation. The present study examined inter-individual variations to meditation through continuous monitoring of EEG, blood pressure, heart rate and its variability (HRV) in novice and experienced meditators. Methods: Participants were 20 experienced and 20 novice meditators involved in a week-long wellness retreat. Monitoring took place during meditation sessions on the first and last full days of the retreat. All participants wore a patch that continuously streamed ECG data, while half of them also wore a wireless EEG headset plus a non-invasive continuous blood pressure monitor. Results: Meditation produced variable but characteristic EEG changes, significantly different from baseline, even among novice meditators on the first day. In addition, although participants were predominately normotensive, the mean arterial blood pressure fell a small (2–3 mmHg) but significant (p < 0.0001) amount during meditation. The effect of meditation on HRV was less clear and influenced by calculation technique and respiration. No clear relationship between EEG changes, HRV alterations, or mean blood pressure during meditation was found. Conclusion: This is the first study to investigate neurological and cardiovascular responses during meditation in both novice and experienced meditators using novel, wearable, wireless devices. Meditation produced varied inter-individual physiologic responses. These results support the need for further investigation of the short- and long-term cardiovascular effects of mental calm and individualized ways to achieve it. PMID:25852526

  5. Undergraduates' understanding of cardiovascular phenomena.

    PubMed

    Michael, Joel A; Wenderoth, Mary Pat; Modell, Harold I; Cliff, William; Horwitz, Barbara; McHale, Philip; Richardson, Daniel; Silverthorn, Dee; Williams, Stephen; Whitescarver, Shirley

    2002-12-01

    Undergraduates students in 12 courses at 8 different institutions were surveyed to determine the prevalence of 13 different misconceptions (conceptual difficulties) about cardiovascular function. The prevalence of these misconceptions ranged from 20 to 81% and, for each misconception, was consistent across the different student populations. We also obtained explanations for the students' answers either as free responses or with follow-up multiple-choice questions. These results suggest that students have a number of underlying conceptual difficulties about cardiovascular phenomena. One possible source of some misconceptions is the students' inability to apply simple general models to specific cardiovascular phenomena. Some implications of these results for teachers of physiology are discussed.

  6. Repeated cold water swim produces delayed nociceptive responses, but not analgesia, for tonic pain in the rat.

    PubMed

    Fuchs, P N; Melzack, R

    1997-05-01

    Earlier studies have demonstrated that cold water swim (CWS) produces stress-induced analgesia in tests of brief, phasic pain and produces a delayed nociceptive response (DNR) for more prolonged tonic pain. The present study reports the effect of repeated CWS on tonic pain, as measured by the formalin test. One group of rats was exposed to a 3.5-min swim in 2 degrees C water immediately prior to the formalin injection, to a 1.5-min swim at 50 min, and to another 1.5-min swim at 100 min postformalin injection. Compared to the no-swim control group, subjects which received repeated CWS had dramatically altered formalin pain responses. Formalin responses began just over 3 h postformalin injection, peaked at 4 h, and were still present at 5 h. Inspection of individual responses revealed a substantial degree of variability in the onset of responses, although the magnitude and duration of the formalin pain response remained at the same levels as those of control subjects. The lack of a decrease in the magnitude and duration of the delayed formalin responses indicates that repeated CWS does not produce analgesia for tonic pain. The period of stress, therefore, produces pain suppression but not loss of the mechanisms that subsequently underlie the pain. Earlier controls have ruled out peripheral mechanisms (such as retention of the formalin in the paw tissue). Rather, a memory mechanism appears to have been indicated and it is not lost, but persists until it can be manifested. Further research is needed to study the mechanisms responsible for the DNR.

  7. Cardiovascular responses to noise: Effects of self-estimated sensitivity to noise, sex, and time of the day

    NASA Astrophysics Data System (ADS)

    di Nisi, J.; Muzet, A.; Weber, L. D.

    1987-04-01

    Eighty subjects of both sexes were selected according to their self-estimated high or low sensitivity to noise. Noise exposure took place during a mental task ("sound" condition) or during a video film illustrating the noises ("sound and video" condition). The experiments were conducted between 0900 and 1100 hours or between 1500 and 1700 hours. Heart rate response and finger pulse response amplitudes were averaged separately for "sound" and "sound and video" conditions. In the "sound" condition, the average amplitude of the heart rate response differed significantly between noise-sensitivity groups: the low sensitivity group showed a lower average amplitude of heart rate response than the high sensitivity group. A significant interaction between sex and time of the day (morning or afternoon) was observed in both "sound" and "sound and video" conditions. In the "sound" condition, the percentage of noises inducing a finger pulse response appeared higher in female than in male subjects.

  8. The American bullfrog (Rana catesbeiana) exhibits differential cardiovascular responses to LTC4 after short- and long-term cold exposure.

    PubMed

    Sun, J; Herman, C A

    1995-02-01

    Mean arterial pressure (MAP) and heart rate (HR) responses to leukotriene (LT)C4 have been studied in warm (W-A) and cold-acclimated (C-A) America bullfrogs, Rana catesbeiana, but nothing is known about how the length of cold treatment affects the response to LTC4 or how responses are affected by return to room temperature following cold exposure. In this study, two groups of frogs were placed at 5 degrees either for 30 days (C-A) or for 1 day (W-C) and LTC4 dose-response curves obtained at 5 degrees. After the frogs were removed from cold, the baseline MAP and HR were monitored for 120 min, and dose-response curves were repeated at 2, 24, and 48 hr. The LTC4 dose-response curves were also obtained during the three experimental days on frogs which had never been placed at cold temperature (W-A). C-A frogs showed greater MAP response than W-C frogs at 5 degrees, and also showed the greatest MAP response of the three groups 48 hr after the animals were removed from cold temperature. These data suggest that up regulation of LTC4 receptors may have occurred in C-A frogs. Cold exposure alone eliminated reflex HR response to LTC4 in both C-A and W-C groups. Longer duration of action was also observed in these groups. The results demonstrate that short-term cold exposure can affect the response to LTC4 in frogs, but that physiological adjustments occur in frogs undergoing long-term exposure.

  9. Intracellular proteins produced by mammalian cells in response to environmental stress

    NASA Technical Reports Server (NTRS)

    Goochee, Charles F.; Passini, Cheryl A.

    1988-01-01

    The nature of the response of mammalian cells to environmental stress is examined by reviewing results of studies where cultured mouse L cells and baby hamster kidney cells were exposed to heat shock and the synthesis of heat-shock proteins and stress-response proteins (including HSP70, HSC70, HSP90, ubiquitin, and GRP70) in stressed and unstressed cells was evaluated using 2D-PAGE. The intracellular roles of the individual stress response proteins are discussed together with the regulation of the stress response system.

  10. Effects of sounds generated by a dental turbine and a stream on regional cerebral blood flow and cardiovascular responses.

    PubMed

    Mishima, Riho; Kudo, Takumu; Tsunetsugu, Yuko; Miyazaki, Yoshifumi; Yamamura, Chie; Yamada, Yoshiaki

    2004-09-01

    Effects of sound generated by a dental turbine and a small stream (murmur) and the effects of no sound (null, control) on heart rate, systolic and diastolic blood pressure, and hemodynamic changes (oxygenated, deoxygenated, and total hemoglobin concentrations) in the frontal cortex were measured in 18 young volunteers. Questionnaires completed by the volunteers were also evaluated. Near-infrared spectroscopy and the Finapres technique were employed to measure hemodynamic and vascular responses, respectively. The subjects assessed the murmur, null, and turbine sounds as "pleasant," "natural," and "unpleasant," respectively. Blood pressures changed in response to the murmur, null, and turbine sound stimuli as expected: lower than the control level, unchanged, and higher than the control level, respectively. Mean blood pressure values tended to increase gradually over the recording time even during the null sound stimulation, possibly because of the recording environment. Oxygenated hemoglobin concentrations decreased drastically in response to the dental turbine sound, while deoxygenated hemoglobin concentrations remained unchanged and thus total hemoglobin concentrations decreased (due to the decreased oxygenated hemoglobin concentrations). Hemodynamic responses to the murmuring sound and the null sound were slight or unchanged, respectively. Surprisingly, heart rate measurements remained fairly stable in response to the stimulatory noises. In conclusion, we demonstrate here that sound generated by a dental turbine may affect cerebral blood flow and metabolism as well as autonomic responses.

  11. Policy options to reduce consumer waste to zero: comparing product stewardship and extended producer responsibility for refrigerator waste.

    PubMed

    Nicol, Scott; Thompson, Shirley

    2007-06-01

    Today, over-consumption, pollution and resource depletion threaten sustainability. Waste management policies frequently fail to reduce consumption, prevent pollution, conserve resources and foster sustainable products. However, waste policies are changing to focus on lifecycle impacts of products from the cradle to the grave by extending the responsibilities of stakeholders to post-consumer management. Product stewardship and extended producer responsibility are two policies in use, with radically different results when compared for one consumer product, refrigerators. North America has enacted product stewardship policies that fail to require producers to take physical or financial responsibility for recycling or for environmentally sound disposal, so that releases of ozone depleting substances routinely occur, which contribute to the expanding the ozone hole. Conversely, Europe's Waste Electrical and Electronic Equipment (WEEE) Directive requires extended producer responsibility, whereby producers collect and manage their own post-consumer waste products. WEEE has resulted in high recycling rates of greater than 85%, reduced emissions of ozone-depleting substances and other toxins, greener production methods, such as replacing greenhouse gas refrigerants with environmentally friendly hydrocarbons and more reuse of refrigerators in the EU in comparison with North America. PMID:17612322

  12. Epigenetics and cardiovascular disease.

    PubMed

    Webster, Andrew L H; Yan, Matthew Shu-Ching; Marsden, Philip A

    2013-01-01

    A commonly-assumed paradigm holds that the primary genetic determinant of cardiovascular disease resides within the DNA sequence of our genes. This paradigm can be challenged. For example, how do sequence changes in the non-coding region of the genome influence phenotype? Why are all diseases not shared between identical twins? Part of the answer lies in the fact that the environment or exogenous stimuli clearly influence disease susceptibility, but it was unclear in the past how these effects were signalled to the static DNA code. Epigenetics is providing a newer perspective on these issues. Epigenetics refers to chromatin-based mechanisms important in the regulation of gene expression that do not involve changes to the DNA sequence per se. The field can be broadly categorized into three areas: DNA base modifications (including cytosine methylation and cytosine hydroxymethylation), post-translational modifications of histone proteins, and RNA-based mechanisms that operate in the nucleus. Cardiovascular disease pathways are now being approached from the epigenetic perspective, including those associated with atherosclerosis, angiogenesis, ischemia-reperfusion damage, and the cardiovascular response to hypoxia and shear stress, among many others. With increasing interest and expanding partnerships in the field, we can expect new insights to emerge from epigenetic perspectives of cardiovascular health. This paper reviews the principles governing epigenetic regulation, discusses their presently-understood importance in cardiovascular disease, and considers the growing significance we are likely to attribute to epigenetic contributions in the future, as they provide new mechanistic insights and a host of novel clinical applications. PMID:23261320

  13. Variable primary producer responses to nutrient and temperature manipulations in mesocosms: temperature usually trumps nutrient effects

    EPA Science Inventory

    Mesocosm experiments have been used to evaluate the impacts of nutrient loading on estuarine plant communities in order to develop nutrient response relationships. Mesocosm eutrophication studies tend to focus on long residence time systems. In the Pacific Northwest, many estuari...

  14. Exercise and the cardiovascular system: clinical science and cardiovascular outcomes.

    PubMed

    Lavie, Carl J; Arena, Ross; Swift, Damon L; Johannsen, Neil M; Sui, Xuemei; Lee, Duck-Chul; Earnest, Conrad P; Church, Timothy S; O'Keefe, James H; Milani, Richard V; Blair, Steven N

    2015-07-01

    Substantial evidence has established the value of high levels of physical activity, exercise training (ET), and overall cardiorespiratory fitness in the prevention and treatment of cardiovascular diseases. This article reviews some basics of exercise physiology and the acute and chronic responses of ET, as well as the effect of physical activity and cardiorespiratory fitness on cardiovascular diseases. This review also surveys data from epidemiological and ET studies in the primary and secondary prevention of cardiovascular diseases, particularly coronary heart disease and heart failure. These data strongly support the routine prescription of ET to all patients and referrals for patients with cardiovascular diseases, especially coronary heart disease and heart failure, to specific cardiac rehabilitation and ET programs.

  15. Correlation of M235T DNA polymorphism with cardiovascular and endocrine responses during physical exercise in healthy subjects.

    PubMed

    Krizanová, O; Koska, J; Vigas, M; Kvetnanský, R

    1998-01-01

    In our experiments, we evaluated the possible effect of M235T molecular variant of the angiotensinogen gene on the response to a physical workload. A group of volunteers was composed of healthy male subjects, approximately of the same weight and height, same age and not actively trained. None of these subjects was under any medication. Blood sampling was carried out via an indwelling catheter. Besides blood pressure and heart rate, angiotensin I, angiotensin II, epinephrine and norepinephrine concentrations were measured in the blood. Our results suggest that only the response of diastolic blood pressure during submaximal exercise corresponded to the presence of M235T molecular variant. In all other parameters we found no significant correlation of the response with the M235T molecular variant. PMID:9706989

  16. Agroinfiltration by cytokinin-producing Agrobacterium sp. strain GV3101 primes defense responses in Nicotiana tabacum.

    PubMed

    Sheikh, Arsheed Hussain; Raghuram, Badmi; Eschen-Lippold, Lennart; Scheel, Dierk; Lee, Justin; Sinha, Alok Krishna

    2014-11-01

    Transient infiltrations in tobacco are commonly used in plant studies, but the host response to different disarmed Agrobacterium strains is not fully understood. The present study shows that pretreatment with disarmed Agrobacterium tumefaciens GV3101 primes the defense response to subsequent infection by Pseudomonas syringae in Nicotiana tabacum. The presence of a trans-zeatin synthase (tzs) gene in strain GV3101 may be partly responsible for the priming response, as the tzs-deficient Agrobacterium sp. strain LBA4404 only weakly imparts such responses. Besides inducing the expression of defense-related genes like PR-1 and NHL10, GV3101 pretreatment increased the expression of tobacco mitogen-activated protein kinase (MAPK) pathway genes like MEK2, WIPK (wound-induced protein kinase), and SIPK (salicylic acid-induced protein kinase). Furthermore, the GV3101 strain showed a stronger effect than the LBA4404 strain in activating phosphorylation of the tobacco MAPK, WIPK and SIPK, which presumably prime the plant immune machinery. Lower doses of exogenously applied cytokinins increased the activation of MAPK, while higher doses decreased the activation, suggesting a balanced level of cytokinins is required to generate defense response in planta. The current study serves as a cautionary warning for plant researchers over the choice of Agrobacterium strains and their possible consequences on subsequent pathogen-related studies. PMID:25054409

  17. Cardiovascular adaptation to spaceflight

    NASA Technical Reports Server (NTRS)

    Hargens, A. R.; Watenpaugh, D. E.

    1996-01-01

    This article reviews recent flight and ground-based studies of cardiovascular adaptation to spaceflight. Prominent features of microgravity exposure include loss of gravitational pressures, relatively low venous pressures, headward fluid shifts, plasma volume loss, and postflight orthostatic intolerance and reduced exercise capacity. Many of these short-term responses to microgravity extend themselves during long-duration microgravity exposure and may be explained by altered pressures (blood and tissue) and fluid balance in local tissues nourished by the cardiovascular system. In this regard, it is particularly noteworthy that tissues of the lower body (e.g., foot) are well adapted to local hypertension on Earth, whereas tissues of the upper body (e.g., head) are not as well adapted to increase in local blood pressure. For these and other reasons, countermeasures for long-duration flight should include reestablishment of higher, Earth-like blood pressures in the lower body.

  18. BIRTH MALFORMATIONS AND OTHER ADVERSE PERINATAL OUTCOMES IN FOUR U.S. WHEAT PRODUCING STATES: RESPONSE

    EPA Science Inventory

    Chlorophenoxy herbicides are widely used in the U.S. and Western Europe for broadleaf weed control in grain farming and park maintenance. Most of the spring and durum wheat produced in the U.S. is grown in Minnesota, Montana, North Dakota, and South Dakota, with over 85% of the a...

  19. Emotional and Cardiovascular Responses to Adults' Angry Behavior and to Challenging Tasks in Children of Hypertensive and Normotensive Parents.

    ERIC Educational Resources Information Center

    Ballard, Mary E.; And Others

    1993-01-01

    Found that, although 10- to 14-year-old sons of hypertensive parents showed greater systolic blood pressure reactivity to interadult anger and to a challenging task than sons of normotensive parents, there was no consistent pattern in the response of girls. (MDM)

  20. Brain mediators of cardiovascular responses to social threat, Part II: Prefrontal-subcortical pathways and relationship with anxiety

    PubMed Central

    Wager, Tor D.; van Ast, Vanessa A.; Hughes, Brent L.; Davidson, Matthew L.; Lindquist, Martin A.; Ochsner, Kevin N.

    2009-01-01

    Social evaluative threat (SET) is a potent stressor in humans linked to autonomic and endocrine responses, and multiple health problems. Neuroimaging has recently begun to elucidate the brain correlates of SET, but as yet little is known about the mediating cortical-brainstem pathways in humans. This paper replicates and extends findings in a companion paper (Wager et al., submitted) using an independent cohort of participants and different image acquisition parameters. Here, we focused specifically on relationships between the medial prefrontal cortex (MPFC), midbrain periaqueductal gray (PAG), and heart rate (HR). We applied multi-level path analysis to localize brain mediators of SET effects on HR and self-reported anxiety. HR responses were mediated by opposing signals in two distinct sub-regions of the MPFC—increases in rostral dorsal anterior cingulate cortex (rdACC) and deactivation in ventromedial prefrontal cortex (vmPFC). In addition, HR responses were mediated by PAG. Additional path analyses provided support for two cortical subcortical pathways: one linking vmPFC, PAG, and HR, and another linking rdACC, thalamus, and HR. PAG responses were linked with HR changes both before and during SET, whereas cortical regions showed stronger connectivity with HR during threat. Self-reported anxiety showed a partially overlapping, but weaker, pattern of mediators, including the vmPFC, dorsomedial PFC (dmPFC), and lateral frontal cortex, as well as substantial individual differences that were largely unexplained. Taken together, these data suggest pathways for the translation of social threats into both physiological and experiential responses, and provide targets for future research on the generation and regulation of emotion. PMID:19465135

  1. A collaborative user-producer assessment of earthquake-response products

    USGS Publications Warehouse

    Gomberg, Joan; Jakobitz, Allen

    2013-01-01

    The U.S. Geological Survey (USGS) and the Washington State Emergency Management Division assessed how well USGS earthquake-response products met the needs of emergency managers at county and local levels. Focus-group responses guided development of new products for testing in a regional-scale earthquake exercise. The assessment showed that (1) emergency responders consider most USGS products unnecessary after the first few postearthquake hours because the products are predictors, and responders are quickly immersed in reality; (2) during crises a significant fraction of personnel engaged in emergency response are drawn from many sectors, increasing the breadth of education well beyond emergency management agencies; (3) many emergency personnel do not use maps; and (4) information exchange, archiving, and analyses involve mechanisms and technical capabilities that vary among agencies, so widely used products must be technically versatile and easy to use.

  2. Psychosocial stress and cardiovascular diseases

    PubMed Central

    Vale, S

    2005-01-01

    Fifty five years after the first finding relating mood disturbances and cardiovascular diseases, there is still debate on the formation of a cogent conception embracing all the fragments of insight within the various aspects relating psychosocial stress to cardiovascular diseases. The clinical comorbidity is empirically evident, but there are ambiguous research results limiting the value of the proposed pathophysiological mechanisms. Psychosocial stress represents here any event that relates psychological phenomena to the social environment and to the associated pathophysiological changes. Stress denotes the external or environmental factors to which people are exposed, as well as the behavioural or biological reaction to it (response that some authors call "distress"). Cardiovascular diseases will be considered here only when being the consequence of chronic inflammatory disease of arteries (atherosclerosis).The question is: Are there pathophysiological reliable mechanisms relating psychosocial stress to the development of cardiovascular diseases? PMID:15998817

  3. Cardiovascular group

    NASA Technical Reports Server (NTRS)

    Blomqvist, Gunnar

    1989-01-01

    As a starting point, the group defined a primary goal of maintaining in flight a level of systemic oxygen transport capacity comparable to each individual's preflight upright baseline. The goal of maintaining capacity at preflight levels would seem to be a reasonable objective for several different reasons, including the maintenance of good health in general and the preservation of sufficient cardiovascular reserve capacity to meet operational demands. It is also important not to introduce confounding variables in whatever other physiological studies are being performed. A change in the level of fitness is likely to be a significant confounding variable in the study of many organ systems. The principal component of the in-flight cardiovascular exercise program should be large-muscle activity such as treadmill exercise. It is desirable that at least one session per week be monitored to assure maintenance of proper functional levels and to provide guidance for any adjustments of the exercise prescription. Appropriate measurements include evaluation of the heart-rate/workload or the heart-rate/oxygen-uptake relationship. Respiratory gas analysis is helpful by providing better opportunities to document relative workload levels from analysis of the interrelationships among VO2, VCO2, and ventilation. The committee felt that there is no clear evidence that any particular in-flight exercise regimen is protective against orthostatic hypotension during the early readaptation phase. Some group members suggested that maintenance of the lower body muscle mass and muscle tone may be helpful. There is also evidence that late in-flight interventions to reexpand blood volume to preflight levels are helpful in preventing or minimizing postflight orthostatic hypotension.

  4. Cardiovascular Disease

    PubMed Central

    Grace, Sherry L; Fry, Rick; Cheung, Angela; Stewart, Donna E

    2004-01-01

    Health Issue Cardiovascular disease (CVD) is the leading cause of death in Canadian women and men. In general, women present with a wider range of symptoms, are more likely to delay seeking medial care and are less likely to be investigated and treated with evidence-based medications, angioplasty or coronary artery bypass graft than men. Key Findings In 1998, 78,964 Canadians died from CVD, almost half (39,197) were women. Acute myocardial infarction, which increases significantly after menopause, was the leading cause of death among women. Cardiovascular disease accounted for 21% of all hospital admissions for Canadian women over age 50 in 1999. Admissions to hospital for ischemic heart disease were more frequent for men, but the mean length of hospital stay was longer for women. Mean blood pressure increases with age in both men and women. After age 65, however, high blood pressure is more common among Canadian women. More than one-third of postmenopausal Canadian women have hypertension. Diabetes increases the mortality and morbidity associated with CVD in women more than it does in men. Depression also contributes to the incidence and recovery from CVD, particularly for women who experience twice the rate of depression as men. Data Gaps and Recommendations CVD needs to be recognized as a woman's health issue given Canadian mortality projections (particularly heart failure). Health professionals should be trained to screen, track, and address CVD risk factors among women, including hypertension, elevated lipid levels, smoking, physical inactivity, depression, diabetes and low socio-economic status. PMID:15345078

  5. Stream mesocosm response sensitivities to simulated ion stress in produced waters from resource extraction activities

    EPA Science Inventory

    To increase the ecological relevance of laboratory exposures intent on determining species sensitivity to ion stress from resource extraction activities we have conducted several stream mesocosm dosing studies that pair single-species and community-level responses in-situ and all...

  6. Elasticity analysis and design for large metabolic responses produced by changes in enzyme activities.

    PubMed Central

    Ortega, Fernando; Acerenza, Luis

    2002-01-01

    Metabolic control analysis has been extensively used to describe how the sensitivity properties of the component enzymes in a metabolic pathway (represented by the elasticity coefficients) determine the way in which metabolic variables respond (described by the control coefficients). Similarly, metabolic control design addresses the inverse problem of obtaining the sensitivity properties of the component enzymes that are required for the system to show a pre-established pattern of responses. These formalisms, including what is called elasticity analysis and design, were developed for small, strictly speaking infinitesimal, changes. Here we extend them to large metabolic responses. The new approach can be applied to simple two-step pathways or to any arbitrary metabolic system divided into two groups linked by one intermediate. General expressions that relate control and elasticity coefficients for large changes are derived. Concentration and flux connectivity relationships are obtained. The relationships for large changes indicate that the pattern of responses is not necessarily the same as the one obtained with the traditional infinitesimal approach, in some cases the patterns being qualitatively different. The general analysis is used to study the control of ketogenesis in rat liver mitochondria, starting from data available in the literature. The control profile of the pathway subject to large changes shows both quantitative and qualitative differences from the one obtained from an analysis that is performed with infinitesimal coefficients. This exemplifies the type of errors that may be introduced when drawing conclusions about large metabolic responses from results obtained with an infinitesimal treatment. PMID:12084013

  7. Rheological properties of a biological thermo-responsive hydrogel produced from soybean oil polymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rheological properties of a newly developed biological thermo-hydrogel made from vegetable oil were investigated. The material named HPSO-HG is a hydrolytic product of polymerized soybean oil (PSO). HPSO-HG is a thermo-responsive gel, and it exhibited viscoelastic behavior above 2% (wt.%) at roo...

  8. Arepas made from ß-glucans enriched corn flour produced low metabolic responses in healthy subjects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn is one of the most important cereals for the nutrition of large groups of the Latin American population and arepa is a very popular corn-based food preparation. In order to study the arepa consumption effects on glucose and insulin response when ß-glucans were added to this preparation, three ...

  9. Short chain fatty acid production and glucose responses by methane producers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fermentation by gut microbiota has been linked to physiologic responses in the host. Methanogenic gut bacteria may remove more carbon from indigestible food matrices especially poorly digested carbohydrates. We sought to assess the effects of methane production on short chain fatty acid (SCFA) con...

  10. Ultrasonic Incisions Produce Less Inflammatory Mediator Response during Early Healing than Electrosurgical Incisions

    PubMed Central

    Shack, Leslie A.; Kumar, Ranjit; Clymer, Jeffrey W.; Korvick, Donna L.; Burgess, Shane C.

    2013-01-01

    As the use of laparoscopic surgery has become more widespread in recent years, the need has increased for minimally-invasive surgical devices that effectively cut and coagulate tissue with reduced tissue trauma. Although electrosurgery (ES) has been used for many generations, newly-developed ultrasonic devices (HARMONIC® Blade, HB) have been shown at a macroscopic level to offer better coagulation with less thermally-induced tissue damage. We sought to understand the differences between ES and HB at a microscopic level by comparing mRNA transcript and protein responses at the 3-day timepoint to incisions made by the devices in subcutaneous fat tissue in a porcine model. Samples were also assessed via histological examination. ES-incised tissue had more than twice as many differentially-expressed genes as HB (2,548 vs 1,264 respectively), and more differentially-expressed proteins (508 vs 432) compared to control (untreated) tissue. Evaluation of molecular functions using Gene Ontology showed that gene expression changes for the energized devices reflected the start of wound healing, including immune response and inflammation, while protein expression showed a slightly earlier stage, with some remnants of hemostasis. For both transcripts and proteins, ES exhibited a greater response than HB, especially in inflammatory mediators. These findings were in qualitative agreement with histological results. This study has shown that transcriptomics and proteomics can monitor the wound healing response following surgery and can differentiate between surgical devices. In agreement with clinical observations, electrosurgery was shown to incur a greater inflammatory immune response than an ultrasonic device during initial iatrogenic wound healing. PMID:24058457

  11. Training grapheme-colour associations produces a synaesthetic Stroop effect, but not a conditioned synaesthetic response.

    PubMed

    Meier, Beat; Rothen, Nicolas

    2009-03-01

    The goal of this study was to investigate whether behavioural and physiological consequences of synaesthesia can be elicited by training specific letter-colour associations. Towards this goal 20 non-synaesthetic individuals were trained for 10 min on 7 consecutive days to associate four different letters with four specific colours. After training, we administered the synaesthetic Stroop test and the synaesthetic conditioning test. The results showed that a 1-week letter-colour association-training was sufficient to elicit a synaesthetic Stroop effect. In contrast, there was no evidence for a conditioned synaesthetic response as measured by skin conductance response in the synaesthetic conditioning test. These results indicate that the presence of a synaesthetic Stroop effect is not unique to true synaesthetes. We discuss methodological, experiential, and neuronal reasons for the dissociation between the synaesthetic Stroop test and the synaesthetic conditioning test.

  12. SvO(2)-guided resuscitation for experimental septic shock: effects of fluid infusion and dobutamine on hemodynamics, inflammatory response, and cardiovascular oxidative stress.

    PubMed

    Rosário, André Loureiro; Park, Marcelo; Brunialti, Milena Karina; Mendes, Marialice; Rapozo, Marjorie; Fernandes, Denise; Salomão, Reinaldo; Laurindo, Francisco Rafael; Schettino, Guilherme Paula; Azevedo, Luciano Cesar P

    2011-12-01

    The pathogenetic mechanisms associated to the beneficial effects of mixed venous oxygen saturation (SvO(2))-guided resuscitation during sepsis are unclear. Our purpose was to evaluate the effects of an algorithm of SvO(2)-driven resuscitation including fluids, norepinephrine and dobutamine on hemodynamics, inflammatory response, and cardiovascular oxidative stress during a clinically resembling experimental model of septic shock. Eighteen anesthetized and catheterized pigs (35-45 kg) were submitted to peritonitis by fecal inoculation (0.75 g/kg). After hypotension, antibiotics were administered, and the animals were randomized to two groups: control (n = 9), with hemodynamic support aiming central venous pressure 8 to 12 mmHg, urinary output 0.5 mL/kg per hour, and mean arterial pressure greater than 65 mmHg; and SvO(2) (n = 9), with the goals above, plus SvO(2) greater than 65%. The interventions lasted 12 h, and lactated Ringer's and norepinephrine (both groups) and dobutamine (SvO(2) group) were administered. Inflammatory response was evaluated by plasma concentration of cytokines, neutrophil CD14 expression, oxidant generation, and apoptosis. Oxidative stress was evaluated by plasma and myocardial nitrate concentrations, myocardial and vascular NADP(H) oxidase activity, myocardial glutathione content, and nitrotyrosine expression. Mixed venous oxygen saturation-driven resuscitation was associated with improved systolic index, oxygen delivery, and diuresis. Sepsis induced in both groups a significant increase on IL-6 concentrations and plasma nitrate concentrations and a persistent decrease in neutrophil CD14 expression. Apoptosis rate and neutrophil oxidant generation were not different between groups. Treatment strategies did not significantly modify oxidative stress parameters. Thus, an approach aiming SvO(2) during sepsis improves hemodynamics, without any significant effect on inflammatory response and oxidative stress. The beneficial effects associated

  13. Oral and oronasal breathing during continuous exercise produce similar responses to ozone inhalation

    SciTech Connect

    Adams, W.C.; Schelegle, E.S.; Shaffrath, J.D. )

    1989-09-01

    Breathing route has a profound effect on sulfur dioxide-induced pulmonary function response in human subjects. There is comparatively little evidence of the effects of oral, nasal, and oronasal breathing on ozone (O3)-induced responses in humans. In this study, six young adult males were exposed on five occasions to 0.40 parts per million (ppm) O3 while exercising continuously at one of two workloads (minute ventilation, VE, of approximately 30 and 75 l/min). The VE exposure time product was similar for all protocols. Four exposures were delivered randomly with a Hans-Rudolph respiratory valve attached to a silicone facemask, with breathing route effected with and without noseclip. A 2 x 2 analysis of variance revealed no statistically significant differences (p less than .05) across conditions in pulmonary function, exercise ventilatory pattern, or subjective symptoms responses. The fifth exposure, delivered via the same respiratory valve with mouthpiece, but without facemask, revealed significantly greater forced expiratory volume in 1 s (FEV1.0) impairment than that observed for the respiratory valve, facemask with noseclip exposure (-20.4% and -15.9%, respectively). The latter suggests partial O3 reactivity to the facemask and clean shaven facial surface of the subjects, although reduced oral scrubbing by mouthpiece-induced bypassing of the oral vestibule might account, in part, for this difference. Recent O3 uptake evidence from another laboratory, however, supports our conclusion that breathing route during moderate and heavy continuous exercise does not affect acute physiologic responses to 0.40 ppm O3.

  14. Tissue-Specific Activation of a Single Gustatory Receptor Produces Opposing Behavioral Responses in Drosophila

    PubMed Central

    Joseph, Ryan M.; Heberlein, Ulrike

    2012-01-01

    Understanding sensory systems that perceive environmental inputs and neural circuits that select appropriate motor outputs is essential for studying how organisms modulate behavior and make decisions necessary for survival. Drosophila melanogaster oviposition is one such important behavior, in which females evaluate their environment and choose to lay eggs on substrates they may find aversive in other contexts. We employed neurogenetic techniques to characterize neurons that influence the choice between repulsive positional and attractive egg-laying responses toward the bitter-tasting compound lobeline. Surprisingly, we found that neurons expressing Gr66a, a gustatory receptor normally involved in avoidance behaviors, receive input for both attractive and aversive preferences. We hypothesized that these opposing responses may result from activation of distinct Gr66a-expressing neurons. Using tissue-specific rescue experiments, we found that Gr66a-expressing neurons on the legs mediate positional aversion. In contrast, pharyngeal taste cells mediate the egg-laying attraction to lobeline, as determined by analysis of mosaic flies in which subsets of Gr66a neurons were silenced. Finally, inactivating mushroom body neurons disrupted both aversive and attractive responses, suggesting that this brain structure is a candidate integration center for decision-making during Drosophila oviposition. We thus define sensory and central neurons critical to the process by which flies decide where to lay an egg. Furthermore, our findings provide insights into the complex nature of gustatory perception in Drosophila. We show that tissue-specific activation of bitter-sensing Gr66a neurons provides one mechanism by which the gustatory system differentially encodes aversive and attractive responses, allowing the female fly to modulate her behavior in a context-dependent manner. PMID:22798487

  15. A Permanent Change In Protein Mechanical Responses Can Be Produced By Thermally Induced Microdomain Mixing

    PubMed Central

    Sallach, Rory E.; Leisen, Johannes; Caves, Jeffrey M.; Fotovich, Emily; Apkarian, Robert P.; Conticello, Vincent P.; Chaikof`, Elliot L.

    2009-01-01

    Electrospinning was employed to fabricate three dimensional fiber networks from a recombinant amphiphilic elastin-mimetic triblock protein polymer and the effects of moderate thermal conditioning (60°C, 4h) on network mechanical responses investigated. Significantly, while cryo-high resolution scanning electron microscopy (cryo-HRSEM) revealed that macroscopic and microscopic morphology of the network structure was unchanged, solid-state 1H NMR spectroscopy demonstrated enhanced interphase mixing of hydrophobic and hydrophilic blocks. Significantly, thermal annealing triggered permanent changes in network swelling behavior (28.75 ± 2.80 non-annealed vs. 13.55 ± 1.39 annealed; p < 0.05) and uniaxial mechanical responses, including Young’s modulus (0.170 ± 0.010 MPa non-annealed vs. 0.366 ± 0.05 MPa annealed; p < 0.05) and ultimate tensile strength (0.079 ± 0.008 MPa vs 0.119 ± 0.015 MPa; p < 0.05). To our knowledge, these investigations are the first to note that mechanical responses of protein polymers can be permanently altered through a temperature-induced change in microphase mixing. PMID:19619402

  16. Cardiovascular and sympathetic responses to a mental stress task in young patients with hypertension and/or obesity.

    PubMed

    Garafova, A; Penesova, A; Cizmarova, E; Marko, A; Vlcek, M; Jezova, D

    2014-01-01

    Present study was aimed to investigate sympathetic responses to mental stress with hypothesis that the presence of obesity in patients with hypertension has a modifying effect. Young male subjects, 8 with hypertension grade I, with BMI 25 kg/m(2) (HT), 10 with hypertension grade I, and BMI 30 kg/m(2) (HT OB), 14 healthy controls with BMI 30 kg/m(2) (OB), and 13 healthy controls with BMI 25 kg/m(2) (C) underwent the Stroop test. ECG was recorded continuously to evaluate heart rate variability (HRV). Blood pressure (BP) and catecholamine concentrations were measured at baseline, at the end of mental stress test and 15 min thereafter. Patients with HT demonstrated increased adrenaline concentrations and enhanced stress-induced noradrenaline release compared to that in healthy controls. In obese subjects, stress-induced increase of systolicBP was lower compared to lean individuals. Stress exposure induced a significant rise in the low frequency power component of HRV, however the increase was lower in the HT OB group compared to C. Obesity in patients with hypertension did not lead to a different reaction in comparison with lean hypertensive subjects. The present data demonstrate higher sympathoadrenal activity in early-stage of hypertension. Obesity is connected with higher resting systolicBP and modifies the HRV response to mental stress.

  17. Extended producer responsibility for packaging wastes and WEEE - a comparison of implementation and the role of local authorities across Europe.

    PubMed

    Cahill, Rachel; Grimes, Sue M; Wilson, David C

    2011-05-01

    A comparison of the implementation of extended producer responsibility (EPR) to packaging waste and waste electrical and electronic equipment (WEEE) is presented for a representative sample of eleven European Union countries based on five indicators: stakeholders and responsibilities; compliance mechanisms; role of local authorities; financing mechanisms and merits and limitations, with four countries selected for more detailed case study analysis. Similarities, trends and differences in national systems are highlighted with particular focus on the role of local authorities and their relationship with obligated producers and the effect on the operation and success of each system. The national systems vary considerably in design, in terms of influence of pre-existing policy and systems, methods of achieving producer compliance (multiple or single collective schemes), fee structures, targets, waste stream prioritization and local authority involvement. Differing approaches are evident across all member states with respect to the role played by local authorities, responsibility apportioned to them, and the evolution of working relationships between obligated producers and municipalities. On the whole, EPR for packaging and WEEE has been successfully implemented throughout Europe in terms of Directive targets. It is, however, clear that the EPR systems currently in application across Europe differ primarily due to contrasting opinion on the legitimacy of local authorities as stakeholders and, in some cases, a fear on the part of industry of associated costs. Where local authorities have been engaged in the design and implementation of national systems, existing infrastructure used and defined roles established for producers and local authorities, results have been significantly more positive than in the cases where local authorities have had limited engagement.

  18. Globalization, Work, and Cardiovascular Disease.

    PubMed

    Schnall, Peter L; Dobson, Marnie; Landsbergis, Paul

    2016-10-01

    Cardiovascular disease (CVD), a global epidemic, is responsible for about 30% of all deaths worldwide. While mortality rates from CVD have been mostly declining in the advanced industrialized nations, CVD risk factors, including hypertension, obesity, and diabetes, have been on the increase everywhere. Researchers investigating the social causes of CVD have produced a robust body of evidence documenting the relationships between the work environment and CVD, including through the mechanisms of psychosocial work stressors. We review the empirical evidence linking work, psychosocial stressors, and CVD. These work stressors can produce chronic biologic arousal and promote unhealthy behaviors and thus, increased CVD risk. We offer a theoretical model that illustrates how economic globalization influences the labor market and work organization in high-income countries, which, in turn, exacerbates job characteristics, such as demands, low job control, effort-reward imbalance, job insecurity, and long work hours. There is also a growing interest in "upstream" factors among work stress researchers, including precarious employment, downsizing/restructuring, privatization, and lean production. We conclude with suggestions for future epidemiologic research on the role of work in the development of CVD, as well as policy recommendations for prevention of work-related CVD. PMID:27604540

  19. Globalization, Work, and Cardiovascular Disease.

    PubMed

    Schnall, Peter L; Dobson, Marnie; Landsbergis, Paul

    2016-10-01

    Cardiovascular disease (CVD), a global epidemic, is responsible for about 30% of all deaths worldwide. While mortality rates from CVD have been mostly declining in the advanced industrialized nations, CVD risk factors, including hypertension, obesity, and diabetes, have been on the increase everywhere. Researchers investigating the social causes of CVD have produced a robust body of evidence documenting the relationships between the work environment and CVD, including through the mechanisms of psychosocial work stressors. We review the empirical evidence linking work, psychosocial stressors, and CVD. These work stressors can produce chronic biologic arousal and promote unhealthy behaviors and thus, increased CVD risk. We offer a theoretical model that illustrates how economic globalization influences the labor market and work organization in high-income countries, which, in turn, exacerbates job characteristics, such as demands, low job control, effort-reward imbalance, job insecurity, and long work hours. There is also a growing interest in "upstream" factors among work stress researchers, including precarious employment, downsizing/restructuring, privatization, and lean production. We conclude with suggestions for future epidemiologic research on the role of work in the development of CVD, as well as policy recommendations for prevention of work-related CVD.

  20. PPARs and the Cardiovascular System

    PubMed Central

    Hamblin, Milton; Chang, Lin; Fan, Yanbo; Zhang, Jifeng

    2009-01-01

    Abstract Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone-receptor superfamily. Originally cloned in 1990, PPARs were found to be mediators of pharmacologic agents that induce hepatocyte peroxisome proliferation. PPARs also are expressed in cells of the cardiovascular system. PPARγ appears to be highly expressed during atherosclerotic lesion formation, suggesting that increased PPARγ expression may be a vascular compensatory response. Also, ligand-activated PPARγ decreases the inflammatory response in cardiovascular cells, particularly in endothelial cells. PPARα, similar to PPARγ, also has pleiotropic effects in the cardiovascular system, including antiinflammatory and antiatherosclerotic properties. PPARα activation inhibits vascular smooth muscle proinflammatory responses, attenuating the development of atherosclerosis. However, PPARδ overexpression may lead to elevated macrophage inflammation and atherosclerosis. Conversely, PPARδ ligands are shown to attenuate the pathogenesis of atherosclerosis by improving endothelial cell proliferation and survival while decreasing endothelial cell inflammation and vascular smooth muscle cell proliferation. Furthermore, the administration of PPAR ligands in the form of TZDs and fibrates has been disappointing in terms of markedly reducing cardiovascular events in the clinical setting. Therefore, a better understanding of PPAR-dependent and -independent signaling will provide the foundation for future research on the role of PPARs in human cardiovascular biology. Antioxid. Redox Signal. 11, 1415–1452. PMID:19061437

  1. PPARs and the cardiovascular system.

    PubMed

    Hamblin, Milton; Chang, Lin; Fan, Yanbo; Zhang, Jifeng; Chen, Y Eugene

    2009-06-01

    Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone-receptor superfamily. Originally cloned in 1990, PPARs were found to be mediators of pharmacologic agents that induce hepatocyte peroxisome proliferation. PPARs also are expressed in cells of the cardiovascular system. PPAR gamma appears to be highly expressed during atherosclerotic lesion formation, suggesting that increased PPAR gamma expression may be a vascular compensatory response. Also, ligand-activated PPAR gamma decreases the inflammatory response in cardiovascular cells, particularly in endothelial cells. PPAR alpha, similar to PPAR gamma, also has pleiotropic effects in the cardiovascular system, including antiinflammatory and antiatherosclerotic properties. PPAR alpha activation inhibits vascular smooth muscle proinflammatory responses, attenuating the development of atherosclerosis. However, PPAR delta overexpression may lead to elevated macrophage inflammation and atherosclerosis. Conversely, PPAR delta ligands are shown to attenuate the pathogenesis of atherosclerosis by improving endothelial cell proliferation and survival while decreasing endothelial cell inflammation and vascular smooth muscle cell proliferation. Furthermore, the administration of PPAR ligands in the form of TZDs and fibrates has been disappointing in terms of markedly reducing cardiovascular events in the clinical setting. Therefore, a better understanding of PPAR-dependent and -independent signaling will provide the foundation for future research on the role of PPARs in human cardiovascular biology.

  2. Cardiovascular reactivity, stress, and physical activity

    PubMed Central

    Huang, Chun-Jung; Webb, Heather E.; Zourdos, Michael C.; Acevedo, Edmund O.

    2013-01-01

    Psychological stress has been proposed as a major contributor to the progression of cardiovascular disease (CVD). Acute mental stress can activate the sympathetic-adrenal-medullary (SAM) axis, eliciting the release of catecholamines (NE and EPI) resulting in the elevation of heart rate (HR) and blood pressure (BP). Combined stress (psychological and physical) can exacerbate these cardiovascular responses, which may partially contribute to the elevated risk of CVD and increased proportionate mortality risks experienced by some occupations (e.g., firefighting and law enforcement). Studies have supported the benefits of physical activity on physiological and psychological health, including the cardiovascular response to acute stress. Aerobically trained individuals exhibit lower sympathetic nervous system (e.g., HR) reactivity and enhanced cardiovascular efficiency (e.g., lower vascular reactivity and decreased recovery time) in response to physical and/or psychological stress. In addition, resistance training has been demonstrated to attenuate cardiovascular responses and improve mental health. This review will examine stress-induced cardiovascular reactivity and plausible explanations for how exercise training and physical fitness (aerobic and resistance exercise) can attenuate cardiovascular responses to stress. This enhanced functionality may facilitate a reduction in the incidence of stroke and myocardial infarction. Finally, this review will also address the interaction of obesity and physical activity on cardiovascular reactivity and CVD. PMID:24223557

  3. Characterization of the cytotoxin produced by macrophages in response to dengue virus-induced cytotoxic factor.

    PubMed Central

    Gulati, L.; Chaturvedi, U. C.; Mathur, A.

    1983-01-01

    We have observed earlier that dengue type 2 virus-induced cytotoxic factor (CF) induces macrophages to produce a c