A5020707125- Cardiac Imaging and Diagnostics
- Neonatal Respiratory Health Research
- Coronary Interventions and Diagnostics
- Pesticide Exposure and Toxicity
- Sulfur Compounds in Biology
- Acute Myocardial Infarction Research
- Cancer, Hypoxia, and Metabolism
- Receptor Mechanisms and Signaling
- Redox biology and oxidative stress
- Occupational exposure and asthma
- Neuroscience of respiration and sleep
- Congenital Diaphragmatic Hernia Studies
- Advanced MRI Techniques and Applications
- Asthma and respiratory diseases
- Adenosine and Purinergic Signaling
- Heme Oxygenase-1 and Carbon Monoxide
- Chronic Obstructive Pulmonary Disease (COPD) Research
- Quantum Dots Synthesis And Properties
- Respiratory Support and Mechanisms
- Interstitial Lung Diseases and Idiopathic Pulmonary Fibrosis
- Retinoids in leukemia and cellular processes
- CRISPR and Genetic Engineering
- Hormonal and reproductive studies
- Air Quality and Health Impacts
- Cardiac Arrhythmias and Treatments
Harry Perkins Institute of Medical Research
2015-2024
University of Colorado Anschutz Medical Campus
1998-2024
The University of Melbourne
2024
Australian Research Council
2018-2024
The University of Western Australia
2015-2024
University of Nottingham
2018-2024
University of Birmingham
2018-2024
Queen Elizabeth II Medical Centre
2016-2024
University of Rochester
2024
University of Colorado Denver
2013-2022
To assess visual interpretation of the coronary arteriogram as a means predicting physiologic effects obstructions in human beings, we compared caliper measurements degree stenosis with reactive hyperemic response flow velocity studied Doppler technique at operation, after 20 seconds arterial occlusion. In 39 patients (44 vessels) isolated, discrete lesions varying severity from 10 to 95 per cent stenosis, measurement percentage angiograms was not significantly correlated (r = -0.25)...
Assessment of coronary blood flow and the vasodilator reserve capacity individual arteries in catheterization laboratory has been hampered by methodologic limitations. We have developed validated a small Doppler catheter that can subselectively measure phasic velocity (CBFV). In seven anesthetized calves, CBFV was varied from 0.1 to 5.7 times control CBFV. Changes mean measured intraluminally left anterior descending circumflex were similar those simultaneously with an epicardial probe on...
Covalent conjugation of superoxide dismutase and catalase with polyethylene glycol (PEG) increases the circulatory half-lives these enzymes from less than 10 min to 40 h, reduces immunogenicity, decreases sensitivity proteolysis. Because PEG has surface active properties can induce cell fusion, we hypothesized that could enhance binding association normally membrane-impermeable enzymes. Incubation cultured porcine aortic endothelial cells 125I-PEG-catalase or 125I-PEG-superoxide produced a...
The effect of hyperoxia on activity the superoxide-sensitive citric acid cycle enzyme aconitase was measured in cultured human epithelial-like A549 cells and rat lungs. Rapid progressive loss > 80% seen during a 24-hr exposure to PO2 600 mmHg (1 = 133 Pa). Inhibition mitochondrial respiratory capacity correlated with exposed hyperoxia, this could be mimicked by fluoroacetate (or fluorocitrate), metabolic poison aconitase. Exposure rats an atmospheric 760 or 635 for 24 hr caused respective...
An ideal coronary vasodilator for studying flow reserve in humans would rapidly produce maximal vasodilation, be short acting to permit repeated measurements, and not alter systemic hemodynamics. The two commonly used vasodilators (dipyridamole meglumine diatrizoate) do satisfy these criteria; diatrizoate does hyperemia dipyridamole has a long duration of effect (greater than 30 min). In this study we subselective Doppler catheter measure the dose-response kinetics shorter vasodilator,...
The results of previous work from this laboratory have shown a poor correlation between percent stenosis (determined visually with calipers) and the coronary reactive hyperemic response (an index maximal vasodilator capacity) determined during cardiac surgery. This study was performed to determine whether other parameters lesion severity could predict thus hemodynamic significance stenoses in human beings. Twenty-three patients lesions proximal left anterior descending artery were studied....
To determine the effects of coronary angioplasty on flow reserve (CFR), we studied 32 patients before and immediately after single-vessel 31 evaluated late (7.5 +/- 1.2 months, mean SEM). The geometry (percent area stenosis minimal cross-sectional area) each lesion was determined by quantitative angiography (Brown/Dodge method) integrated optical density measured videodensitometry. CFR with a No. 3F Doppler catheter placed proximal to maximally vasodilating dose intracoronary papaverine....
Studies in animals with normal coronary arteries have shown that flow reserve can be predicted by angiographic measurements of arterial stenosis. man, however, suggest even quantitative analysis angiograms cannot predict the physiologic significance individual lesions. These studies, were carried out patients either widespread, diffuse artery disease or measurement techniques tend to underestimate maximal reserve. To determine relationship between stenosis and (CFR) discrete limited...
We tested the hypothesis that lesion rethrombosis after streptokinase reperfusion is related to luminal size of residual stenosis. Two independent techniques analyzing coronary angiograms, quantitative angiography and computer-based videodensitometry, were used estimate lumen immediately discontinuation streptokinase. These selected because they provide estimates cross-sectional area a with high degrees reproducibility minimal observer variability. Twenty-four patients who had undergone...
To define the long-term variability of serial coronary flow reserve (CFR) measurements in humans and to evaluate influence changes heart rate, mean arterial pressure, left ventricular preload on CFR, 45 patients with normal function (38 cardiac allograft recipients, five arteries, two minimal artery disease [less than 50% diameter stenosis]) were studied. CFR (ratio peak hyperemic [h] resting [r] blood velocity [CBFV]) was measured a 3F Doppler catheter intracoronary papaverine. Initial...
Background —The Post Coronary Artery Bypass Graft Trial, designed to compare the effects of 2 lipid-lowering regimens and low-dose anticoagulation versus placebo on progression atherosclerosis in saphenous vein grafts patients who had CABG surgery, demonstrated that aggressive lowering LDL cholesterol (LDL-C) levels <100 mg/dL compared with a moderate reduction 132 136 decreased grafts. Low-dose did not significantly affect progression. Methods Results —Approximately 3 years after last...
Hearts isolated from rats pretreated 24 hr before with endotoxin had increased myocardial catalase activity, but the same superoxide dismutase, glutathione peroxidase, reductase, and glucose-6-phosphate dehydrogenase activities, as hearts untreated rats. also function (decreased injury) after ischemia reperfusion (Langendorff apparatus, 37 degrees C), assessed by measurement of ventricular developed pressure, contractility (+dP/dt), relaxation rate (-dP/dt), compared to control hearts. In...
Cardiac transplantation (CT) causes total cardiac denervation.To test directly for sympathetic reinnervation in humans, we measured the release of norepinephrine (NE) response to tyramine (an agent that NE from intact nerve terminals) and sustained handgrip exercise (a reflex stimulus) 12 patients less than 5 months after CT, 50 1 year or more eight without CT. Plasma [NE] was aorta [( NE]Ao) coronary sinus NE]CS) at rest, administration (55 micrograms/kg, i.v.), during exercise. determined...
To study whether atrial fibrillation might produce local changes in the atrium which could facilitate tendency of this arrhythmia to become chronic and self-perpetuating, we compared effect fibrillation, pacing, acute volume loading on perfusion oxygen consumption anesthetized dogs. Measurement with microspheres indicates that during blood flow increases 2- 3-fold. Right pacing is a significantly less potent metabolic stimulus for vasodilation. Using Doppler velocity recordings sinus node...