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Results 401 - 450 of 517
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Buser P T - - 1990
There is controversy as to whether potent inotropic agents are beneficial or detrimental in moderate to severe heart failure. Accordingly, we studied the effects of amrinone, amrinone plus dobutamine, and dobutamine alone on mechanical performance, myocardial oxygen consumption, and high energy phosphate metabolism in different stages of congestive heart failure ...
Sater A K - - 1990
We have examined the tissue interactions responsible for the expression of heart-forming potency during gastrulation. By comparing the specification of different regions of the marginal zone, we show that heart-forming potency is expressed only in explants containing both the dorsal lip of the blastopore and deep mesoderm between 30 degrees ...
Tucker D C - - 1990
Culture of embryonic heart in the anterior eye chamber allows neurohumoral and genetic controls of cardiac development to be separated from the influence of hemodynamic load. Hearts from 12-day gestation rat embryos grafted into the anterior eye chamber of an adult host rat attach to the iris and become vascularized ...
Shen P S - - 1989
Recessive mutant gene c for "cardiac nonfunction" in axolotls results in an absence of normal heart contractions in affected embryos due to a failure of myofibril formation. In the present study, the intermediate filament protein, desmin, is compared in developing normal and mutant hearts by means of two-dimensional gel electrophoresis, ...
Mabuchi K - - 1989
By fixing the function of one ventricle, a total right heart bypass model can clarify the function and regulatory mechanism of the natural heart, and the etiology of abnormal hemodynamics in TAH animals such as increased CVP blood pressure and hepatic congestion. The pulmonary artery of a right heart bypass ...
Sater A K - - 1989
The establishment of heart mesoderm during Xenopus development has been examined using an assay for heart differentiation in explants and explant combinations in culture. Previous studies using urodele embryos have shown that the heart mesoderm is induced by the prospective pharyngeal endoderm during neurula and postneurula stages. In this study, ...
Nelson C V - - 1989
We have measured magnitude and location of heart dipole moment during QRS in 46 New Zealand white rabbits. The spatial magnitude curve had one to three peaks. Mean values were M1 = 80 +/- 10 microA-cm (N = 5) pointing to right anterior and caudal, M2 = 260 +/- 15 ...
Mandarim-de-Lacerda C A - - 1989
The heart of 3 human embryos at 17 mm C-R (stade 19) was studied by means of light microscopy and quantitative methods. The serial sections of the embryos were projected for the measurement of the cardiac diameters and cardiac profile areas (point-counting planimetry). The calculated heart volume for each embryo ...
Satoh M - - 1988
The effect of pretreatment of mice with heavy metals: Zn, Cu, Bi, Co, Cd or Hg, against lethal and cardiac toxicity of adriamycin (ADR) was investigated. The lethal toxicity of ADR was significantly reduced by pre-administration of these metals except for Cu. The levels of both malondialdehyde and conjugated dienes, ...
Anderson R H - - 1988
In the past, it has often been the case that congenital malformations have been categorized in terms of their presumed embryologic development. The knowledge of development, however, has itself often been derived from studies of the normal heart during its development coupled with inferences drawn from the morphology of the ...
Wolkowicz J - - 1988
An Inuit family from Cape Dorset, Northwest Territories is described; six had documented complete heart block, one high grade atrioventricular block, one bi- or trifascicular block and all suffered syncope. One other member received a pacemaker for unknown reasons. Two of three middle-aged relatives had minor conduction abnormalities. All younger ...
Melinek R - - 1988
The heart of the axolotl Ambystoma mexicanum was studied with histochemical methods to determine the distribution of neurons containing acetylcholine esterase, catecholamines and 5-hydroxytryptamine. The cardiac ganglion is made up of cholinergic nerve fibers and somata, and of catecholaminergic fibers. Small intensely fluorescent cells were found along blood vessels in ...
Bojenko S - - 1988
A case of a 36-year-old pilot with a left sided accessory pathway (Kent bundle) is presented. The electrophysiological study revealed spontaneous changes in atrioventricular conduction in both the accessory and physiological pathways, lack of retrograde conduction via accessory pathway, and constant ventriculoatrial block in the atrioventricular node during the pacing ...
Satoh K - - 1988
The efficacy of MCI-154, a new pyridazinone cardiotonic agent, in improving heart failure was assessed in dog heart-lung preparations in which cardiac function had been severely depressed by pentobarbital. MCI-154 in doses of 10-100 micrograms improved the cardiac function curve and restored it to the control level at 100 micrograms. ...
Magaribuchi T - - 1988
Two rat hearts were perfused in series by a modified Loewi's method. The recipient heart was perfused with the perfusate collected from the donor heart. 1. After perfusion with 3H-isoprenaline in the presence of tropolone, an inhibitor of catechol-O-methyltransferase, the donor heart was washed out with amine-free medium containing tropolone ...
Jakab G - - 1988
Phosphorylation of phospholipids was studied in Langendorff perfused guinea pig hearts subjected to beta-adrenergic stimulation. Hearts were perfused with Krebs-Henseleit buffer containing [32P]Pi and freeze-clamped in a control condition or at the peak of the inotropic response to isoprenaline. 32P incorporation into total phospholipids, individual phospholipids and polyphosphoinositides was analysed ...
Runnalls M E - - 1987
An Ag-AgCl electrode for recording monophasic action potentials by pressure contact is described. The electrode is mounted in a hand-held support designed for epicardial recordings during open-heart surgery from both the anterior and lateral walls of the left ventricle with minimal displacement of the heart. The support allows the electrode ...
Barry A C - - 1987
To compare the function of old and young hearts contracting under identical conditions, isolated hearts of young and old C57BL/6J mice were perfused using a Langendorff preparation. During a 3-min period of anoxia some hearts showed a decrease in systolic pressure, while other hearts developed contracture. The incidence and magnitude ...
Slinker B K - - 1987
Recently proposed concepts of pericardial surface pressure, as opposed to liquid pressure, have advanced our understanding of the relationship between pericardial and heart chamber pressures. However, the subsequent suggestion that right heart intracavitary pressure equals, or nearly equals, pericardial surface pressure is not strictly consistent with the physiology of pericardial ...
Tanaka M - - 1987
To define the pathogenetic role of myocardial fiber disarray in the progression of cardiac fibrosis, the percent area of fibrosis in tissue with disarray was compared with that in tissue without disarray. Thirty autopsied hearts, 10 from patients with hypertrophic cardiomyopathy, 10 from patients with hypertension and 10 from normal ...
Nilsson G - - 1987
The relation between distribution patterns of ventricular premature complexes (VPCs) and heart rate in Holter recordings abundant in VPCs was analyzed using computer-assisted determination of the number of interectopic sinus beats at different heart rates. Within the complete 24-hour heart rate spectrum, zones were demonstrated that were characterized by manifest ...
Hill K E - - 1987
Selenium deficiency causes a fall in rat cardiac glutathione peroxidase activity. As a consequence, isolated perfused selenium-deficient heart does not release increased amounts of GSSG when hydroperoxide is infused. However, the total amount of glutathione measured as intracellular GSH, intracellular GSSG and GSSG released from the heart when hydroperoxide is ...
Bisaillon A - - 1987
The heart of the beluga whale (Delphinapterus leucas) is described from the dissection of seven specimens. As in most whales the heart is characterized by a transverse broadness and a flatness of the ventricles from one surface to the other and by an apex formed by both ventricles. Heart size ...
Dunaway G A - - 1986
The nature of 6-phosphofructo-1-kinase isozyme pools in fetal, neonatal, young adult (3 months), and aged (30 months) rat hearts was studied using chromatographic and immunological techniques. Furthermore, the changing subunit composition of each isozyme pool was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis on 6% slab gels and by immunoblotting ...
Fuller R W - - 1986
A single dose of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) in mice caused 75-87% depletion of heart norepinephrine (NE) concentration 24 hrs later. MPP+ (1-methyl-4-phenylpyridinium) caused similar depletion of heart NE. The effect of MPTP was not blocked by pretreatment with deprenyl, an inhibitor of type B monoamine oxidase (MAO-B). Also, deprenyl pretreatment did ...
Stewart D E - - 1986
Neural crest cells are known to contribute to the normal architecture of the heart and aortic arch arteries. Ablation of neural crest cells over somites 1 to 3 in the chick embryo prevents conotruncal septation and results in persistent truncus arteriosus. To determine whether a deficiency of cardiac neural crest ...
Dor V - - 1986
Twenty-two heterotopic heart transplantations were performed, in 19 of which the evolution of the recipient heart was estimated. Within the first postoperative hours the recipient heart was often more effective than the donor heart. The discrepant rhythm between the 2 hearts did not result in any pathological findings. The increased ...
Borkowf A - - 1986
We report on the ventricular pressor response and regional (head, heart, and body) uptake of dopamine hydrochloride (DA) following topical application of a teratogenic dose to the stage 24 chick embryo. Embryos treated with DA exhibited a significant increase in mean ventricular blood pressure (MVBP) at 0.5 and 1 hour ...
Nousiainen J J - - 1986
The normal vector magnetocardiogram and its statistical variation are described in detail. The magnetic heart vector of 18 healthy subjects is detected with the corrected unipositional lead system and analysed together with the simultaneously recorded Frank vector electrocardiogram. The mean values and standard errors for the magnitudes and directions of ...
Altieri F D - - 1986
The National Heart, Lung, and Blood Institute (NHLBI) has sponsored considerable research directed toward basic studies on the etiology of heart disease and atherosclerosis. While progress has been very encouraging there are still significant numbers of patients with end-stage heart disease. NHLBI initiated goal-oriented research activities on the artificial heart ...
Paquin M - - 1986
The present state of artificial heart research and development is analyzed in light of public perceptions affected by accounts of the experiences of those who received the Jarvik-7. On the assumption that research will continue, it is argued that the therapeutic goals of the artificial heart can be realized, and ...
Hirsch C S - - 1986
Approximately 15% of victims of instantly lethal central nervous system trauma have an empty or nearly empty heart at autopsy. This article defines and discusses the "empty heart" sign.
Magovern J H - - 1986
Severe cardiac malformations may involve the atrioventricular valve region, but the sequence of embryonic development of this important area has been little studied. In particular, the basis of atrioventricular muscular discontinuity, except at the conduction system, has remained unexplained. To examine this question, serial histologic sections of human embryos from ...
Alpert N R - - 1986
This is a review of work dealing with the contribution of myocardial myosin isoenzymes to the performance of the heart muscle. Isoenzyme composition is altered in rabbit hearts by banding the pulmonary artery (increase in %V3) and thyroid hormone injection (increase in V1). Both treatments result in myocardial hypertrophy. The ...
Pang J A - - 1986
Shoshin beriberi, a fulminant form of heart failure due to thiamine deficiency has a different presentation to the classical form of beriberi heart failure. It is characterized by a cold periphery, low blood pressure, renal shutdown and a severe metabolic acidosis. The true incidence is unknown. Two patients were seen ...
Leifer M C - - 1986
Ionic currents flowing during the activation of the heart generate both electric potentials which can be recorded at the body surface as the electrocardiogram or ECG and magnetic fields which can also be recorded at the body surface as what is termed the magnetocardiogram (MCG). In order to apply the ...
Cullen B M - - 1985
Several anaesthetics were tested with mice to study: (a) their ability to immobilize the animal; (b) their effect on blood pressure and heart rate; and (c) their effect on the response to X-irradiation of the mouse sarcoma RIF-1. All anaesthetics which produced adequate immobilization also caused a fall in blood ...
Kurosawa H - - 1985
In the definitive heart the anterior continuation of the main conduction axis is considered to be the right bundle branch. In this study three hearts from neonates and infants were examined in which this situation did not pertain. The conduction axis continued beyond the point of origin of the right ...
Kuramoto T - - 1985
Impulse activity of the bursting neurones in the intact or segmented cardiac ganglion could be recorded in the isolated and freely beating hearts of lobsters. In the segmented ganglion, the four large cells (LCs), the medium cell (MC), and the four small cells (SCs) generated phasic, short tonic, and long ...
Legato M J - - 1984
Several qualitative features of the ultrastructure of pressure overload and thyrotoxic myocardium are unique markers of the type and quantity of increased work the heart has been required to perform. Furthermore, they are reminiscent of features of normally growing myocytes, implying that the changes in the hypertrophied cell are the ...
Furspan P B - - 1984
Only recently have the cardiac actions of parathyroid hormone and its N-terminal (1-34) fragment (bPTH(1-34] been examined. Parathyroid hormone was found to exert a positive chronotropic effect on the heart tissue of several mammals and one amphibian in vivo and/or in vitro. The purpose of the present study was to ...
Anderson R H - - 1984
Most hearts described as "single ventricle" or "univentricular heart" possess 2 ventricular chambers, even though 1 is usually described as an "outlet chamber." This stems from the wide acceptance that the criterion of a single ventricle is the presence of a double-inlet atrioventricular (AV) connection. In recent years, using this ...
Barsacchi R - - 1984
Diamide, CDNB and phorone were used to deplete glutathione in retrogradely perfused rat hearts. Following glutathione depletion the spontaneous chemiluminescence increased by 70%, irrespective of the agent used. The glutathione depletion and the chemiluminescence emission were associated to an increase of malondialdehyde content in the heart, as determined by HPLC. ...
Iwaya F - - 1984
Twenty-seven calves were operated on in our institute for total artificial heart replacement. Thomasu hearts (made by the Thomasu Technical Company, Japan) were used in 21 calves from February 1980 to May 1983. Utah Jarvik 7 hearts were used for the first five calves and the 17th calf. The air-driven ...
Peterson D A - - 1984
It is here proposed that disordered redox balance leads to congestive heart failure in a variety of diverse clinical situations. These conditions include those associated with an excess of reducing agents, such as catecholamines and thyroid hormone, or impaired oxidant defenses, such as in selenium deficiency. The clinical situations include ...
Delise P - - 1984
Experimental and clinical studies have demonstrated the existence of phase 3 and phase 4 functional blocks. In this report six cases are presented in which the electrophysiological study demonstrated the existence of a functional intraventricular block different from phase 3 and phase 4 blocks. In these cases the occurrence of ...
Perez M A - - 1984
The action of sodium salicylate on normal and digoxin-intoxicated rabbit heart was studied by the Langendorff perfusion method. The drug depressed heart rate, atrioventricular (AV) conduction and contraction force in the normal heart, and reversibly blocked the ventricular pacemakers induced by digoxin intoxication, whereas its effect on sinoatrial frequency as ...
Oreto G - - 1984
We report an example of ventricular fusion of a sinus impulse conducted with bundle branch block with an ectopic impulse arising on the ipsilateral side of the blocked bundle branch. The manifestation simulates the normalization which occurs during the relatively slow phase of a tachycardia dependent left bundle branch block.
Riemenschneider T A - - 1983
We examined the potential for laser irradiation of congenital heart defects, with the use of postmortem hearts and an argon ion laser with a flexible quartz fiber. Atrial septectomy was performed in five newborn hearts. Obstructive lesions were relieved by laser irradiation in valvular pulmonic and aortic stenosis, dysplastic pulmonary ...
Antzelevitch C - - 1983
A protected ectopic focus created in tissue excised from one heart was allowed to interact with the activity of the intact heart of another animal. The protected focus consisted of a Purkinje fiber in which a narrow central zone was rendered inexcitable. The model permitted us to study parasystole, modulated ...
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