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Results 351 - 400 of 530
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Freeman L M - - 1998
Alterations in body composition and nutritional status are common in humans with heart failure and are related, in part, to increases in cytokine concentrations. Cytokines have not been studied previously in dogs with naturally occurring cardiac disease nor has fish oil administration been used in this population to decrease cytokine ...
Wu T J - - 1998
OBJECTIVES: We sought to evaluate the characteristics of wave fronts during ventricular fibrillation (VF) in human hearts with dilated cardiomyopathy (DCM) and to determine the role of increased fibrosis in the generation of reentry during VF. BACKGROUND: The role of increased fibrosis in reentry formation during human VF is unclear. ...
Sueshiro M - - 1998
In the process of developing a completely implantable total artificial heart system, we have made an eccentric roller type total artificial heart and evaluated it by means of a mock circulatory system and by an acute animal experiment. The actuator of the artificial heart consists of 2 cylindrical drum type ...
Huang G Y - - 1998
Connexin 43 (Cx43) knockout mice and transgenic mice (CMV43) overexpressing the Cx43 gap junction gene exhibit heart defects involving the conotruncus and right ventricle. Based on the heart phenotype and Cx43 gene and transgene expression pattern, we previously proposed that the heart defects may reflect a role for gap junctions ...
Hajjar R J - - 1998
We used a catheter-based technique to achieve generalized cardiac gene transfer in vivo and to alter cardiac function by overexpressing phospholamban (PL) which regulates the activity of the sarcoplasmic reticulum Ca2+ ATPase (SERCA2a). By using this approach, rat hearts were transduced in vivo with 5 x 10(9) pfu of recombinant ...
Pietersen H G - - 1998
Glutamate infusion has been shown to exert beneficial hemodynamic effects in patients with heart failure after cardiac surgery. To elucidate the underlying mechanism we studied the possibility that glutamate is a Krebs-cycle precursor in the human heart. Therefore [1-13C]glutamate was infused in order to show production of 13CO2 by the ...
Knowlton A A - - 1998
BACKGROUND: Heat shock proteins (hsp) constitute an endogenous stress response that protects cells from injury. Most work on these important proteins has focused on the immediate response to acute stress in cell culture systems and mammalian models of heart disease. Little is known about the expression of the hsps in ...
Holly R G - - 1998
Physical conditioning induces numerous cardiovascular adaptations, including vagotonia and increased cardiac volume and mass. These adaptations characterise the 'athletic heart' and account for most of the normal variants in the athlete's electrocardiogram. Common alterations associated with vagotonia include sinus bradycardia, sinus arrhythmia, junctional escape beats, first degree atrioventricular block and ...
Badeer H S - - 1998
It has been observed that climbing arboreal snakes have hearts closer to the head than nonclimbing terrestrial or aquatic snakes. The closeness to the head is said to minimize the work of the heart in pumping blood to the head. However, there is ample evidence that the gravitational pressure in ...
Neuburger M - - 1998
In the present study we examined light-microscopically the nuclei of 16 hearts (7 normal hearts, 7 hearts with hypertrophy and 2 hearts with atrophy) for the size, number and morphology of their nucleoli. The size of the nucleoli, defined as the total area of all nucleoli per nucleus, was an ...
Aydinlio─člu A - - 1998
The normally developing cardiovascular system of the chicken resembles that of the human. The purpose of the present study is to investigate some macroscopic and microscopic similarities between the chick and the human heart. For this study 20 adult and 10 newborn Broiler chickens were used. The heart and great ...
Canny M - - 1997
A test was attempted of the assumption that, when a leaf is cut, the xylem still contains water under tension beyond the first vessel cross walls. This assumption enabled Scholander to argue that the balance pressure in his pressure chamber measured the tension in water columns in the vessels before ...
Acierno R - - 1997
Channichthyid icefishes of Antarctica are unique among adult vertebrates. All icefish species lack hemoglobin and red blood cells in their circulating blood. All icefishes examined to date also lack the intracellular oxygen-binding protein myoglobin (Mb) in their oxidative skeletal muscles. However, some icefish species do express Mb in their heart ...
Thivierge M - - 1997
Rotating fibers in the heart lead to a myocardium of inhomogeneous anisotropic conductivity. Besides affecting the activation isochrones, this anisotropy modifies the equivalent dipoles used in calculating extracardiac potentials, rendering them oblique rather than normal to the activation wavefront due to an added axial dipole component oriented along the fibers. ...
Dalecki D - - 1997
Earlier studies have shown that a single, millisecond duration pulse of ultrasound delivered to the frog heart in vivo during systole can produce a reduction in the developed aortic pressure, while a pulse delivered during diastole can produce a premature ventricular contraction. The threshold for these effects is 5-10 MPa ...
Anderson P A - - 1996
The perspective from which the developing heart is viewed can lead to differing conclusions about the effects of development on cardiac function. The hearts of the embryo, fetus and adult, viewed from a global perspective, sustain the circulation through the same basic mechanisms of developing pressure and ejecting blood. The ...
Louzada P R PR - - 1996
Effects of hydrostatic pressure on the fluorescence emission of L-tryptophan, N-acetyl-L-trytophanamide and indole were investigated. An increase in pressure ranging from 1 bar to 2.4 kbar results in reversible red-shifts of the emission of the three fluorophores. The pressure-induced redshift amounts to about 170 cm(-1) at 2.4 kbar, and appears ...
Barragán J M - - 1996
This study was designed to determine the interactions of peptide exendin-(9-39) with the effect of glucagon-like peptide-1-(7-36) (GLP-1 (7-36)) amide and of exendin-4 on arterial blood pressure and heart rate in the rat. Both GLP-1 (7-36) amide and exendin-4 produced a dose-dependent increase in systolic, diastolic and mean arterial blood ...
Ferrari R - - 1996
Congestive heart failure is a clinical syndrome in which the capacity of the heart to maintain cardiac output is impaired. As a consequence, blood pressure is threatened and endocrine and paracrine mechanisms are activated to preserve circulatory homeostasis and to maintain blood pressure. At terminal stages, a complex multiorgan syndrome ...
Linck B - - 1996
1. The effect of the phosphatase inhibitor, cantharidin (3-300 microM) on force of contraction was studied in isolated electrically driven right ventricular trabeculae carneae from human myocardium. 2. The positive inotropic effect of cantharidin started at a concentration of 100 microM with a positive inotropic effect to 199% and to ...
Nimon A J - - 1996
A technique for the noninvasive measurement of heart rate in incubating penguins is described and evaluated. The technique uses an artificial egg fitted with an infrared sensor. Placing the egg in the nest causes minimal disturbance to the resident penguin; this penguin is then paint-marked so that subsequent measurements may ...
Biggers V - - 1996
Do belching, chills, fatigue, and pressure just above the ribs sound like the symptoms of a heart attack? To most patients, they probably don't. However, research is indicating that a victim's actual symptoms often do not match his or her expectations of what a heart attack should feel like. As ...
Yamamoto S - - 1996
Intercellular dehiscence is a common cardiocytic response to pathological conditions. However, little consideration has been given to the possibility of new intercellular junctions developing between cardiocytes within developed myocardium. To examine this possibility as it may relate to useful compensation for hemodynamic overloads, changes in cardiocytic connection were evaluated by ...
Kocijancic S - - 1996
The left ventricular pressure (LVP) and ECG signals that appear during and after ischaemia tend to be very irregular (fibrillation, arrhythmia). Computer based data acquisition system, that we developed to support experiments on isolated Langendorff's rat heart, enabled the usage of methods derived from non-linear dynamics. To classify the irregularity ...
Llobel F - - 1996
We have examined the effects of morphine in auricular myocardium from non-failing and failing human hearts. In both preparations morphine induced inhibition. These responses were not antagonized by naloxone. Comparison of mean IC30 values obtained in non-failing (3.9 (SEM 0.2) x 10(-8) mol litre-1) and failing (5010 (200) x 10(-8) ...
Schönekess B O - - 1995
Propionyl L-carnitine (PLC) is a naturally occurring derivative of L-carnitine that can improve hemodynamic function of hypertrophied rat hearts. The mechanism(s) responsible for the beneficial effects of PLC is not known, although improvement of myocardial energy metabolism has been suggested. In this study, we determined the effect of PLC on ...
Wada S - - 1995
BACKGROUND: FC43 emulsion is one of several perfluorochemical-based artificial blood compounds developed as a red blood cell substitute. However, these compounds are not promising as red blood cell substitutes because of their immunosuppressive effects. Therefore we used FC43 emulsion as an immunosuppressive agent and not as a red blood cell ...
Gwathmey J K - - 1995
Is contractility depressed in the failing human heart? The question must be approached in a stringent manner. Myocardium from failing human hearts has been shown to generate normal physiological force under the ideal conditions of low stimulation and an adequate energy supply. Nevertheless, even when subjected to physiologically conducive conditions, ...
Ebisawa K - - 1995
A family was investigated because of heart block and sinus arrhythmia. The electrical characteristics were: (1) adult onset in all members; (2) complete heart block with atrial fibrillation in 2, and first- or second-degree heart block in 7 members; and (3) sinus arrhythmia in 3 members. Human leukocyte antigen (HLA) ...
Broderick T L - - 1995
Carnitine-deficiency syndromes are often associated with alterations in lipid metabolism and cardiac function. The present study was designed to determine whether this is also seen in an experimental model of carnitine deficiency. Carnitine deficiency was induced in male Sprague-Dawley rats supplemented with sodium pivalate for 26 to 28 weeks. This ...
Nascone N - - 1995
Heart induction in Xenopus has been thought to be dependent primarily on the interaction of the heart primordia with the Spemann organizer. We demonstrate, however, that signals derived from the deep dorsoanterior endoderm during early gastrulation are also essential for heart formation. The presence of deep endoderm dramatically enhances heart ...
Buchanan J W - - 1995
A method for measuring canine heart size in radiographs was developed on the basis that there is a good correlation between heart size and body length regardless of the conformation of the thorax. The lengths of the long and short axes of the heart of 100 clinically normal dogs were ...
Hertel W - - 1995
So-called accessorial pulsatile circulatory organs in insects have developed during evolutionary reduction of the vascular system. As such a peripheral organ, the antenna-heart supplies the antennae with haemolymph. In the antenna-heart, the beat rhythm is generated by a myogenic automatism and is controlled neuronally. The electrical stimulation of the antenna-heart ...
Männer J - - 1995
It has been proposed that the cervical flexure of vertebrate embryos arises from the normal morphogenesis of the heart. This hypothesis is based on experiments in which the heart tube is removed or disrupted in early chick embryos. It has been reported that, in normal atmosphere, these embryos continued normal ...
La France S - - 1994
Tropomyosin is a major component of the thin filaments in organized myofibrils of cardiac muscle cells. A purported role for this protein is to prevent myosin thick filaments from interacting with actin thin filaments until the cell contracts. Recently, tropomyosin has been implicated in actin filament formation/stabilization as well. In ...
Chen M S MS - - 1994
We present data on the effects of a heart health education intervention targeted at adult Southeast Asians. Within each of the Cambodian, Laotian, and Vietnamese groups who received the intervention, we obtained random samples approximately three to 18 months postintervention. Comparisons were made between preintervention and postintervention knowledge of blood ...
Walia B N - - 1994
The paper reports a syndrome in which oblique placement of one or both the pinnae on face was found to co-exist with congenital anomalies of heart like VSD, PDA and Tetralogy of Fallot, etc. Although clinically discernible in 90% of the subjects, objective evidence of obliquity of pinna was documented ...
Li H G - - 1993
Increased circulating catecholamines are considered to be arrhythmogenic in heart failure. It is unclear whether increased circulating catecholamines contribute directly to ventricular arrhythmias or are only markers of the severity of heart failure. The present study determined the sensitivity of the failing heart to the arrhythmogenic effect of exogenous norepinephrine ...
Xie J T - - 1993
Monophasic action potentials (MAPs) are a measure of electrical activity of local myocardial cells recorded from the epicardial or endocardial surfaces of the beating heart, in vivo, using a positive pressure-contact electrode or electrode catheter. The MAP technique is a reliable and safe method for studying and detecting the cardiac ...
Segel L D - - 1993
These experiments tested the hypothesis that addition of pyruvate to a preservation medium would improve postpreservation cardiac function as quantified in an isolated working heart model after heterotopic transplantation. Four groups of rabbit hearts were studied (n = 5 per group): fresh controls, fresh hearts perfused as isolated working hearts; ...
McKean T A - - 1993
The purpose of this study was to compare the responses of isolated hearts of the diving muskrat with the nondividing guinea pig (GP) to determine the contribution of adenosine (ADO) to the profound bradycardia that was seen in isolated muskrat hearts during exposure to hypoxia. Muskrat hearts were more sensitive ...
Carver W - - 1993
Significant physiological changes occur in the heart following birth including increased arterial blood pressure and heart rate. Concurrently, biochemical and structural alterations are evident in the neonatal heart in response to these dynamic physiological properties. Prominent among these is the elaborate development of the cardiac extracellular matrix, composed primarily of ...
Goldstein L J - - 1993
This paper details a versatile and easy to use electrical network model of the heart in which the user can control the heart rate, blood pressure, end-diastolic left ventricular pressure, and proportion of time spent in systole. Several dysrhythmias and cardiac diseases can be simulated, including asystole, second and third ...
Frunchak Y N - - 1993
The early heart anlagen of Xenopus laevis embryos were exposed to purified embryonic galactoside-binding lectin or its potent hapten inhibitor thiodigalactoside (TDG). Heart development was then studied using a variety of microscopical techniques. Conotruncal morphology and positioning with respect to the ventricle are altered in treated animals. In 34% of ...
Laflamme A K - - 1992
Clentiazem, 8-chloro diltiazem, is a calcium channel blocker currently undergoing evaluation for the treatment of stable angina and hypertension. As patients with ischaemic disorders often present some degree of heart failure, the aim of this study was to investigate the effect of congestive heart failure on clentiazem (200 micrograms kg-1, ...
Alpert N R - - 1992
A myothermal/mechanical analysis on non-failing and failing human hearts and normal and pressure overloaded rabbit hearts is reported. Heat production is partitioned into tension-dependent and tension-independent components together with force measurements to provide information about calcium and cross-bridge cycling. In the non-failing human heart the cross-bridge force-time integral is 0.51 ...
Alvarez L - - 1992
The effects of fentanyl at a dose of 100 micrograms.kg-1 on cardiac automaticity, refractoriness and conduction have been studied in a model of heterotopic heart transplantation which combines a denervated heart (donor) and a non-denervated heart (recipient) in each of 20 dogs employed. Once the surgical procedure had been completed, ...
Tsao C Y - - 1992
The majority of patients with Friedreich ataxia present with gait ataxia. Congestive heart failure usually is a terminal event. We report a 9-year-old boy who developed congestive heart failure and thrombus formation in the left ventricle at age 5 years and then progressive ataxia as well as other features of ...
Kageyama M - - 1992
We investigated the effects of semotiadil (SD-3211), a novel calcium antagonist, on blood pressure and the atrioventricular (AV) conduction time and functional refractory period (FRP) of the AV conduction system (AV conductivity) in anesthetized open-chest dogs. The heart was electrically stimulated at a constant rate. In dogs with an intact ...
Murtagh J - - 1992
Palpitations are an unpleasant awareness of beating of the heart. By definition, the condition does not always imply 'racing' of the heart but encompasses any sensation in the chest such as 'pounding', 'flopping', 'skipping', 'jumping', 'thumping' or 'fluttering' of the heart. The problem requires careful attention and reassurance because heart ...
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