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The Effects of Hypothermia on the Release of Cardiac Enzymes

Description: The myocardium is known to release CPK, LDH1 , and GOT in response to ischemia as a result of myocardial infarction. This study was designed to induce the release of cardiac enzymes without adversely effecting the myocardium by perfusion hypothermia, thereby suggesting that these enzymes are not as specific in the diagnosis of myocardial infarction as once thought. Hypothermia was by in vivo perfusion of the left anterior descending coronary artery. Enzyme activity was measured from sera samples spectrophotometrically and electrophoretically. Significant CPK and LDH1 increases were observed in animals perfused between 25 and 19 C. These results indicate that, while heart function remained unchanged, an alteration occurred in the membrane integrity of the myocardial cells.
Date: August 1977
Creator: Strawn, William B.
Partner: UNT Libraries

Lack of MEF2A mutations in coronary artery disease

Description: Mutations in MEF2A have been implicated in an autosomal dominant form of coronary artery disease (adCAD1). In this study we sought to determine whether severe mutations in MEF2A might also explain sporadic cases of coronary artery disease (CAD). To do this, we resequenced the coding sequence and splice sites of MEF2A in {approx}300 patients with premature CAD and failed to find causative mutations in the CAD cohort. However, we did identify the 21 base pair (bp) MEF2A coding sequence deletion originally implicated in adCAD1 in one of 300 elderly control subjects without CAD. Further screening of an additional {approx}1,500 non-CAD patients revealed two more subjects with the MEF2A 21 bp deletion. Genotyping of 19 family members of the three probands with the 21 bp deletion in MEF2A revealed that the mutation did not co-segregate with early CAD. These studies demonstrate that MEF2A mutations are not a common cause of CAD and cast serious doubt on the role of the MEF2A 21 bp deletion in adCAD1.
Date: December 1, 2004
Creator: Weng, Li; Kavaslar, Nihan; Ustaszewska, Anna; Doelle, Heather; Schackwitz, Wendy; Hebert, Sybil et al.
Partner: UNT Libraries Government Documents Department

Simulations of laser thrombolysis

Description: The authors have shown that bubble expansion and collapse near the interface between two materials with modest property differences produces jet-like interpenetration of the two materials. The bubble dynamics at a water-viscous fluid interface is compared with that at the interface of water with a weak elastic-plastic material. The authors find that, despite rather similar behavior during bubble growth and the initial portion of bubble collapse, the terminal jetting behavior is quite different, even in direction. The elastic-plastic properties chosen realistically represent real and surrogate thrombus. Simulations using the elastic-plastic model quantitatively agree with laboratory thrombolysis mass removal experiments. In the earlier simulations of laboratory experiments, walls have been remote so as to not effect the dynamics. Here the authors present two-dimensional simulations of thrombolysis with water over elastic-plastic surrogate thrombus in a geometry representative of the clinical situation. The calculations include thin cylindrical elastic walls with properties and dimensions appropriate for arteries. The presence of these artery walls does not substantially change the interface jetting predicted in unconfined simulations.
Date: March 1, 1999
Creator: Chapyak, E. J. & Godwin, R. P.
Partner: UNT Libraries Government Documents Department

Use of Reactor-Produced Radioisotopes for Prevention Restenosis After Angioplasty

Description: Coronary heart disease leads to myocardial infarction and is a major cause of death in the US. Myocardial infarctions result from atherosclerotic plaque deposits in the coronary arteries, reducing blood flow through these arteries which supply oxygen and nutrients to the heart muscle. The two major approaches for restoring adequate blood flow are coronary bypass graft surgery and coronary angioplasty. Angioplasty is a routinely used clinical procedure, where a deflated balloon attached to the end of a long catheter is inserted into an artery in the leg and then advanced through the aorta into the blocked regions of the coronary arteries. After positioning in the occluded region of the artery, the balloon is inflated with a pressurized saline solution which opens the artery restoring blood flow by pressing the atherosclerotic plaque into the vessel wall. Angioplasty is a widely performed procedure with the coronary arteries and is a much less expensive alternative to coronary bypass surgery. The best patients for angioplasty are those with single occlusions and this method is preferred over bypass grafting because of the significantly reduced expense. The reformation of plaque deposits in arteries (restenosis) following angioplasty, however, is a major clinical problem encountered in as high as 40 percent of patients. Because reduction of health care costs is a major national priority, development of effective new preventative methods for restenoses is an important national priority.
Date: December 21, 1999
Creator: Knapp, F.F. & Pipes, D.W.
Partner: UNT Libraries Government Documents Department

Reconstruction and Visualization of Fiber and Laminar Structure inthe Normal Human Heart from Ex Vivo DTMRI Data

Description: Background - The human heart is composed of a helicalnetwork of muscle fibers. These fibers are organized to form sheets thatare separated by cleavage surfaces. This complex structure of fibers andsheets is responsible for the orthotropic mechanical properties ofcardiac muscle. The understanding of the configuration of the 3D fiberand sheet structure is important for modeling the mechanical andelectrical properties of the heart and changes in this configuration maybe of significant importance to understand the remodeling aftermyocardial infarction.Methods - Anisotropic least square filteringfollowed by fiber and sheet tracking techniques were applied to DiffusionTensor Magnetic Resonance Imaging (DTMRI) data of the excised humanheart. The fiber configuration was visualized by using thin tubes toincrease 3-dimensional visual perception of the complex structure. Thesheet structures were reconstructed from the DTMRI data, obtainingsurfaces that span the wall from the endo- to the epicardium. Allvisualizations were performed using the high-quality ray-tracing softwarePOV-Ray. Results - The fibers are shown to lie in sheets that haveconcave or convex transmural structure which correspond to histologicalstudies published in the literature. The fiber angles varied depending onthe position between the epi- and endocardium. The sheets had a complexstructure that depended on the location within the myocardium. In theapex region the sheets had more curvature. Conclusions - A high-qualityvisualization algorithm applied to demonstrated high quality DTMRI datais able to elicit the comprehension of the complex 3 dimensionalstructure of the fibers and sheets in the heart.
Date: December 18, 2006
Creator: Rohmer, Damien; Sitek, Arkadiusz & Gullberg, Grant T.
Partner: UNT Libraries Government Documents Department


Description: Determining the health impacts of different sources and components of fine particulate matter (PM2.5) is an important scientific goal, because PM is a complex mixture of both inorganic and organic constituents that likely differ in their potential to cause adverse health outcomes. The TERESA (Toxicological Evaluation of Realistic Emissions of Source Aerosols) study focused on two PM sources - coal-fired power plants and mobile sources - and sought to investigate the toxicological effects of exposure to realistic emissions from these sources. The DOE-EPRI Cooperative Agreement covered the performance and analysis of field experiments at three power plants. The mobile source component consisted of experiments conducted at a traffic tunnel in Boston; these activities were funded through the Harvard-EPA Particulate Matter Research Center and will be reported separately in the peer-reviewed literature. TERESA attempted to delineate health effects of primary particles, secondary (aged) particles, and mixtures of these with common atmospheric constituents. The study involved withdrawal of emissions directly from power plant stacks, followed by aging and atmospheric transformation of emissions in a mobile laboratory in a manner that simulated downwind power plant plume processing. Secondary organic aerosol (SOA) derived from the biogenic volatile organic compound {alpha}-pinene was added in some experiments, and in others ammonia was added to neutralize strong acidity. Specifically, four scenarios were studied at each plant: primary particles (P); secondary (oxidized) particles (PO); oxidized particles + secondary organic aerosol (SOA) (POS); and oxidized and neutralized particles + SOA (PONS). Extensive exposure characterization was carried out, including gas-phase and particulate species. Male Sprague Dawley rats were exposed for 6 hours to filtered air or different atmospheric mixtures. Toxicological endpoints included (1) breathing pattern; (2) bronchoalveolar lavage (BAL) fluid cytology and biochemistry; (3) blood cytology; (4) in vivo oxidative stress in heart and lung tissue; and (5) heart and ...
Date: March 31, 2011
Creator: Rohr, Annette C.; Koutrakis, Petros & Godleski, John
Partner: UNT Libraries Government Documents Department

Positron emission tomographic imaging of tumors using monoclonal antibodies. Progress report, April 15, 1992--October 31, 1992

Description: This research project is developing methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). This report describes the development of methods for labeling MAbs and their fragments with positron-emitting halogen nuclides, fluorine-18 and iodine-124. These nulides were selected because of the widespread availability of F-18 and because of our extensive experience in the development of new protein radiohalogenation methods.
Date: August 1, 1992
Creator: Zalutsky, M. R.
Partner: UNT Libraries Government Documents Department

Applications of CdTe to nuclear medicine. Annual report, February 1, 1979-January 31, 1980

Description: The application of CdTe gamma detectors in nuclear medicine is reported on. An internal probe was developed which can be inserted into the heart to measure the efficiency of various radiopharmaceuticals in the treatment of heart attacks. A second application is an array of detectors which is light enough to be worn by ambulatory patients and can measure the change in cardiac output over an eight hour period during heart attack treatment. The instrument includes an on board tape recorder. (ACR)
Date: January 1, 1980
Creator: Entine, G
Partner: UNT Libraries Government Documents Department

What has happened to the survivors of the early Los Alamos nuclear accidents

Description: Two nuclear accidents involving a plutonium sphere just subcritical in size occurred at the Los Alamos Laboratory, LA-1 in 1945 and LA-2 in 1946. Because remote control devices were deemed unreliable at the time, the tamper material (tungsten carbide bricks in LA-1 and beryllium hemispheres in LA-2) was added by hand with the operator standing next to the assembly. In each case the critical size of the assembly was accidentally exceeded and the resultant exponentially increasing chain reaction emitted a burst of neutrons and gamma rays. Ten persons were exposed to the radiation bursts which were largely composed of neutrons. The doses ranged from fatal in the case of the two operators, to small in the case of some survivors. The two operators died within weeks as a result of acute radiation injury. Only six of the eight survivors were available for follow-up study ten or more years after the accident. Four of these six survivors are now dead, but the two living survivors are in excellent health with no clinical or laboratory evidence of late radiation injury. Two of the deceased died of acute myelogenous leukemia, another died at age 83 of refractory anemia, and the fourth of myocardial infarction. The heart attack could have been precipitated by the myxedema assumed to have been the result of the radiation exposure.
Date: January 1, 1979
Creator: Hempelman, L.H.; Lushbaugh, C.C. & Voelz, G.L.
Partner: UNT Libraries Government Documents Department

Positron emission tomographic imaging of tumors using monoclonal antibodies

Description: This research project is developing methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). This report describes the development of methods for labeling MAbs and their fragments with positron-emitting halogen nuclides, fluorine-18 and iodine-124. These nulides were selected because of the widespread availability of F-18 and because of our extensive experience in the development of new protein radiohalogenation methods.
Date: August 1, 1992
Creator: Zalutsky, M.R.
Partner: UNT Libraries Government Documents Department

Noninvasive measurement of regional myocardial glucose metabolism by positron emission computed tomography. [Dogs]

Description: While the results of regional myocardial glucose metabolism measurements using positron emission computed tomography (/sup 13/N-ammonia) are promising, their utility and value remains to be determined in man. If this technique can be applied to patients with acute myocardial ischemia or infarction it may permit delineation of regional myocardial segments with altered, yet still active metabolism. Further, it may become possible to evaluate the effects of interventions designed to salvage reversibly injured myocardium by this technique.
Date: June 1, 1980
Creator: Schelbert, H.R. & Phelps, M.E.
Partner: UNT Libraries Government Documents Department

Interactive radiopharmaceutical facility between Yale Medical Center and Brookhaven National Laboratory. Progress report, November 1, 1980-October 31, 1981

Description: Research conducted in three principal areas is discussed and summarized. (1) Investigation of the influence of antiarrhythmic agents, such as lidocaine and procainamide, on the chemotaxis and nylon fiber adherence of indium-111-labelled human polymorphonulcear leukocytes (PMNs) in vitro revealed that at normal therapeutic levels of lidocaine and procaine, the adherence and chemotactic function of In-111-PMNs remain unaltered. Results with higher therapeutic blood levels are also discussed. (2) An improved method for labeling human platelets with In-111-oxine is outlined, and the influence of centrifugal force, oxine, ethanol, and radiation on platelet function is reported. Results indicate that normal labeling procedures induce no gross changes in platelet function. (3) The chemical preparation of radioiodinated arachidonic acid (AA) and nonradioactive acid ester of AA, and the analysis of metabolites of these compounds following myocardial ischemia were investigated in dogs. The tissue uptake of /sup 131/I-AA was compared to that of thallium-201.
Date: unknown
Creator: Gottschalk, A.
Partner: UNT Libraries Government Documents Department

Nuclear medicine technology. Progress report, quarter ending March 31, 1980

Description: The successful detection of experimentally produced myocardial infarctions in rats and dogs using /sup 123m/Te-9-telluraheptadecanoic acid (9-(/sup 123m/Te)-THDA) is described. Preferential localization of radioactivity in normal myocardial tissue of rats that had experimentally produced infarctions was also demonstrated by tissue distribution studies following injection of 9-(/sup 123m/Te)-THDA. The effects of chain length on the myocardial uptake of /sup 75/Se-labeled long-chain fatty acids was also studied further. Selenium-75-labeled 13-selenaheneicosonic acid (H/sub 3/C-(CH/sub 2/)/sub 7/-/sup 75/Se-(CH/sub 2/)/sub 11/-COOH, 13-(/sup 75/Se)-SHCA) shows the highest heart uptake in rats of the agents studied. These results indicate that myocardial imaging may be possible with 13-(/sup 75/Se)-SHCA and also suggest that potential positron emission tomography of the myocardium with the /sup 73/Se-labeled agent should be explored. The results of continuing studies with /sup 11/C and /sup 195m/Pt-labeled agents are also described. A variety of /sup 11/C-labeled amino acids were prepared and tested as pancreas and tumor localizing agents in a Medical Cooperative Program with the Oak Ridge Associated Universities. The microscale synthesis of /sup 195m/Pt-labeled cis-dichloro-trans-dihydroxy-bis-(isopropylamine)platinum(IV) (/sup 195m/Pt-CHIP) was developed further and preliminary tissue distribution studies with this important second-generation antitumor drug were completed in rats. Platinum-195m-labeled cis-dichlorodiammineplatinum(II) (/sup 195m/Pt-cis-DDP) was supplied for testing to a number of Medical Cooperative Programs. Studies of arsenic trioxide (As/sub 2/O/sub 3/) toxicity for human cells in the diffusion chamber assay system have continued. Further investigation of this arsenic-induced cytotoxicity has demonstrated a linear dose-response relationship and a difference in the permanence of the growth inhibitory effect using different doses.
Date: October 1, 1980
Creator: Knapp, F.F. Jr.
Partner: UNT Libraries Government Documents Department