Browsing by Subject "Systole"

Now showing 1 - 5 of 5
  • Thumbnail Image
    ItemOpen Access
    ACE-inhibition increases podocyte number in experimental glomerular disease independent of proliferation.
    (Journal of the renin-angiotensin-aldosterone system : JRAAS, 2015-06) Zhang, Jiong; Yanez, David; Floege, Anna; Lichtnekert, Julia; Krofft, Ronald D; Liu, Zhi-Hong; Pippin, Jeffrey W; Shankland, Stuart J

    Objective

    The objective of this article is to test the effects of angiotensin-converting enzyme (ACE)-inhibition on glomerular epithelial cell number in an inducible experimental model of focal segmental glomerulosclerosis (FSGS).

    Background

    Although ACE-inhibition has been shown to limit podocyte loss by enhancing survival, little is known about its effect on podocyte number following an abrupt decline in disease.

    Methods

    Experimental FSGS was induced with cytotoxic antipodocyte antibody. Following induction, groups were randomized to receive the ACE-inhibitor enalapril, the smooth muscle relaxant hydralazine (blood pressure control) or drinking water. Blood pressure, kidney function and histology were measured seven and 14 days following disease induction.

    Results

    Both glomerulosclerosis and urinary albumin-to-creatinine ratio were less in the ACE-inhibition arm at day 14. At day 7 of disease, mean podocyte numbers were 26% and 29% lower in the enalapril and hydralazine arms, respectively, compared to normal mice in which no antibody was injected. At day 14, the mean podocyte number was only 18% lower in the enalapril arm, but was 39% lower in the hydralazine arm compared to normal mice. Podocyte proliferation did not occur at any time in any group. Compared to water- or hydralazine-treated mice with FSGS, the enalapril arm had a higher mean number of glomerular parietal epithelial cells that co-expressed the podocyte proteins WT-1 and synaptopodin, as well as phospho-ERK.

    Conclusion

    The results show following an abrupt decline in podocyte number, the initiation of ACE-inhibition but not hydralazine, was accompanied by higher podocyte number in the absence of proliferation. This was accompanied by a higher number of parietal epithelial cells that co-express podocyte proteins. Increasing podocyte number appears to be accompanied by reduced glomerulosclerosis.
  • Thumbnail Image
    ItemOpen Access
    Assessing acute systemic effects of an inhaled drug with serial echocardiography: a placebo-controlled comparison of inhaled and intravenous dihydroergotamine.
    (Drug Des Devel Ther, 2013) Noveck, Robert J; Douglas, Pamela S; Chow, Shein-Chung; Mangum, Barry; Kori, Shashidhar; Kellerman, Donald J
    OBJECTIVE: MAP0004 is an investigational product which delivers dihydroergotamine (DHE) through the lung via a breath-synchronized metered dose inhaler. The objective of this study was to compare the acute effects of orally inhaled and intravenous (IV) DHE to placebo on maximum change and area under the curve for pulmonary arterial systolic pressure (PASP). RESEARCH DESIGN AND METHODS: A randomized, double-blind, placebo-controlled, 3-period, crossover study of 24 health adults. Trial registration NCT01089062. Study assessments included pharmacokinetics, electrocardiograms (ECG), and validated echocardiographic (Doppler)-derived measures of PASP by echocardiogram. The primary endpoint was the absolute change in calculated PASP using area under the curve, 0 to 2 hours (AUC(0-2h)). RESULTS: The change in PASP with IV DHE was significantly different than MAP0004 and placebo (AUC(0-2h)2857, 2624, and 2453 mmHg*min, respectively). After a second dose of MAP0004, AUC(0-4h) remained lower with MAP0004 than with a single dose of IV DHE. Adverse events were more common with IV DHE than with MAP0004 or placebo. None of the treatments produced clinically significant changes in PASP or other cardiac parameters. Changes in PASP were significantly smaller with MAP0004 compared with IV DHE. CONCLUSION: These results indicate the effects 1 mg of orally inhaled DHE on the cardiovascular system are less than with 1 mg of IV DHE, and that serial echocardiography can be a useful noninvasive means of assessing acute systemic effects.
  • Thumbnail Image
    ItemOpen Access
    Blood Pressure Response during Cardiopulmonary Exercise Testing in Heart Failure.
    (Medicine and science in sports and exercise, 2018-07) Il'giovine, Zachary J; Solomon, Nicole; Devore, Adam D; Wojdyla, Daniel; Patel, Chetan B; Rogers, Joseph G

    Introduction

    The prognostic value of peak V˙O2 and V˙E/V˙CO2 slope measured during cardiopulmonary exercise (CPX) testing has been well established in patients with advanced heart failure, but blood pressure response to exercise is less well characterized.

    Methods

    We retrospectively studied 151 outpatients who underwent CPX testing as part of an advanced heart failure evaluation. The outcome of interest was failure of medical management, defined by death, cardiac transplantation, or left ventricular assist device placement. Patients were stratified into tertiles by change in systolic blood pressure (SBP) (<13, 13-26, and ≥27 mm Hg) during exercise.

    Results

    Patients in the lowest tertile had the lowest peak V˙O2 (10.2 vs 10.6 vs 13.6 mL·kg·min, P = <0.001), the highest V˙E/V˙CO2 slope (42.8 vs 42.1 vs 36.3, P = 0.030), the shortest mean exercise time (5.1 vs 6.0 vs 7.0 min, P = <0.001), and the highest probability of failure of medical management at 1.5 yr (0.69 vs 0.41 vs 0.34, P = 0.011). After multivariate adjustment, increased SBP <20 mm Hg during exercise was associated with a lower hazard of medical management failure (hazard ratio = 0.96, 95% confidence interval [CI] = 0.934-0.987), whereas SBP increases >20 mm Hg were associated with an increased hazard (hazard ratio = 1.046, 95% CI = 1.018-1.075).

    Conclusion

    In conclusion, changes in SBP during CPX testing provide additional prognostic information above standard clinical variables. The peculiar increase in risk noted in those with a rise in SBP >20 mm Hg is less clear and needs to be investigated further.
  • Thumbnail Image
    ItemOpen Access
    Intracoronary adenovirus-mediated delivery and overexpression of the beta(2)-adrenergic receptor in the heart : prospects for molecular ventricular assistance.
    (Circulation, 2000-02-01) Glower, Donald D Jr; Hata, Jonathan Andrew; Koch, Walter J; Kypson, Alan P; Lefkowitz, Robert J; Lilly, R Eric; Pippen, Anne; Shah, AS; Silvestry, Scott Christopher; Tai, Oliver
    BACKGROUND: Genetic modulation of ventricular function may offer a novel therapeutic strategy for patients with congestive heart failure. Myocardial overexpression of beta(2)-adrenergic receptors (beta(2)ARs) has been shown to enhance contractility in transgenic mice and reverse signaling abnormalities found in failing cardiomyocytes in culture. In this study, we sought to determine the feasibility and in vivo consequences of delivering an adenovirus containing the human beta(2)AR cDNA to ventricular myocardium via catheter-mediated subselective intracoronary delivery. METHODS AND RESULTS: Rabbits underwent percutaneous subselective catheterization of either the left or right coronary artery and infusion of adenoviral vectors containing either a marker transgene (Adeno-betaGal) or the beta(2)AR (Adeno-beta(2)AR). Ventricular function was assessed before catheterization and 3 to 6 days after gene delivery. Both left circumflex- and right coronary artery-mediated delivery of Adeno-beta(2)AR resulted in approximately 10-fold overexpression in a chamber-specific manner. Delivery of Adeno-betaGal did not alter in vivo left ventricular (LV) systolic function, whereas overexpression of beta(2)ARs in the LV improved global LV contractility, as measured by dP/dt(max), at baseline and in response to isoproterenol at both 3 and 6 days after gene delivery. CONCLUSIONS: Percutaneous adenovirus-mediated intracoronary delivery of a potentially therapeutic transgene is feasible, and acute global LV function can be enhanced by LV-specific overexpression of the beta(2)AR. Thus, genetic modulation to enhance the function of the heart may represent a novel therapeutic strategy for congestive heart failure and can be viewed as molecular ventricular assistance.
  • Thumbnail Image
    ItemOpen Access
    Modified INOvent for delivery of inhaled nitric oxide during cardiac MRI.
    (Magn Reson Imaging, 2011-10) Devendra, Ganesh P; Hart, Stephen A; Kim, Yuli Y; Setser, Randy M; Flamm, Scott D; Krasuski, Richard A
    BACKGROUND: The aim of this study was to assess the feasibility of delivering NO through a modified system to allow clearance of the magnetic field and thus compatibility with cardiac magnetic resonance (CMR). Nitric oxide (NO) is an inhalational, selective pulmonary vasodilator with a wide range of applications in a variety of disease states, including diseases that affect the right ventricle. Accurate assessment of dynamic changes in right ventricular function necessitates CMR; however, delivery of NO is only possible using equipment that is not magnetic resonance imaging (MRI) compatible (INOvent delivery system, Ohmeda, Inc., Madison, WI, USA). METHODS: The INOvent delivery system was modified by using 35 ft. of standard oxygen tubing to allow NO delivery through an electrical conduit and into the MRI suite. The concentrations of oxygen (O(2)), nitrogen dioxide (a harmful byproduct, NO(2)) and NO were measured in triplicate using the built-in electrochemical analyzer on the INOvent. After confirmation of safety, the system was used to administer drug to a patient x, and dynamic MRI measurements were performed. RESULTS: When the standard INOvent was set to administer 40 ppm of NO, the mean/standard deviation of gas delivered was as follows: NO: 42/0 ppm; NO(2): 0.3/0.1 ppm; and O(2): 93/0 ppm. In comparison, the gas delivery of the modified INOvent was follows: NO: 41/0 ppm; NO(2): 0.5/0 ppm; and O(2): 93.7/0.6 ppm. During administration to an index patient with severe pulmonic insufficiency (PI), a measurable reduction in PI was observed by CMR. CONCLUSIONS: Nitric oxide can be administered through 35 ft. of standard oxygen tubing without significantly affecting dose delivery. This technique has potential application in patients with right-sided structural heart disease for determination of dynamic physiological changes.