The hemorrhage, blister formation, and rumplessness observed in the chick embryo following treatment with trypan blue may be due to (1) increased ventricular blood pressure or (2) to necrosis and edema in the caudal region of the embryo by inhibiting nutrient utilization. To test the role of increased ventricular blood ...

The UI Octoson can provide accurate compound and simple scan cross sectional views of the heart. Sections taken in the transverse, sagittal, and other planes normal and parallel to the long axis of the heart are useful for providing full information that may be obtained by the examination. The views ...

In vivo heart rates of 5-day-old chick embryos were recorded from electrodes placed in close proximity to the heart. L-epinephrine (4X10(-10) mole), 1-norepinephrine (1X10(-9)mole) and 1-isoproterenol (1.6X10(-10)mole) in 5 microliter of isotonic saline transiently accerlerated the mean heart rate by almost 9 percent. L-phenylephrine (2X10(-9)mole/5microliter) and the experimental procedure produced ...

The study of transmural activation of the intact heart requires placement of multipolar needle electrodes through the wall of the beating heart. This report describes a method developed for constructing lightweight multipolar needles with 10-30 leads mounted 1 mm apart. The electrodes are constructed from readily available materials and no ...

This report describes the operating characteristics and initial clinical results of a new echocardiographic system that produces real-time, high resolution, cross-sectional images of the heart. This system relies upon phased-array principles to rapidly steer and focus the ultrasound beam through the cardiac structures under investigation. A hand-held, linear array of ...

Glycopyrrolate and atropine were compared as to their effects on heart rate, arrhythmias, blood pressure, and volume of oropharyngeal secretions. Glycopyrrolate protects against neostigmine-induced bradycardia, produces less initial tachycardia, causes a lower incidence of cardiac arrhythmias, and is a superior oropharyngeal drying agent. Use of this drug instead of atropine ...

Electrophysiological and histological observations were made on the heart of the African lungfish. Impulse origin and propagation were studied using simultaneously recorded epicardial and pericardial electrograms. The primary pacemaker site in the lungfish was found to be at the sinus venosus at its junction with the left cardinal vein. Under ...

The prostaglandins (PGs) released from the heart have generally been characterized as resembling PGE by bioassay techniques. The major PG formed from [14C]arachidonate (C20:4) by the isolated perfused rabbit heart has chromatographic mobility similar to that of PGE2 in most solvent systems. However, additional analysis of this radioactive "PGE" peak ...

Myocardial taurine levels were correlated with pulmonary wedge pressure (PWP) in dogs with congestive heart failure (CHF). Heart failure was induced by creating an infrarenal aortocaval fistula. PWP ranged from 6.6 to 28 mm Hg, suggesting a wide range in severity of heart failure in those dogs. Compared to taurine ...

A case of digoxin overdose was described. Despite vigorous gastric lavage, the serum digoxin which was 0.8 ng/ml on admission rose to 7 ng/ml four hours later. The main side-effects were symptoms of nausea and anorexia and conduction defects including complete atrioventricular dissociation requiring pacemaker insertion. Opportunity was taken to ...

An artificial heart constructed from Biomer, a polyurethane, kept a calf alive for more than three months after its natural heart was removed. During this time all of the calf's vital organs apparently functioned well. We had been able to keep similar animals alive with Jarvik III hearts made from ...

Vectorcardiograms were obtained from 50 young domestic pigs using the Nelson lead system. Compensation for body size and shape is achieved and the resultant dipole moment magnitude reflects heart size. A strong relationship was found between heart size and maximum magnitude. Dipole moment magnitude increased as four pigs increased from ...

The effects of the topical application of Dyphylline in concentrations of 1.0 mg/1.0 ml and 10 mg/1.0 ml Ringer's solution and 25 mg/1.0 ml, 0.065% NaCl solution (the content of ampoules in clinical use) were investigated on frog's heart in situ. Dyphylline in all of the above concentrations had a ...

Cardiac hypertrophy in weaning beagle dogs was obtained by a loose aortic banding with a 10-mm Dacron-Teflon band, positioned 1 cm distal from the aortic valve 9 months later all animals developed left ventricular hypertrophy without signs of heart failure. Sarcoplasmic reticulum proteins as well as their calcium-exchanging properties were ...

In experiments with rabbits, glucagon prolonged the half-period of absorption of sodium iodide 125J in the left ventricular myocardium. Regitine prevented acceleration of the heart rate and impairment of capillary flow after glucagon. In healthy rabbits hippurate 125J clearance was unaffected by glucagon. After injury of the heart muscle by ...

Thirty-six harbor porpoises, Phocaena phocaena, were caught off the coast of Southern New Brunswick and Nova Scotia as part of a study of the biology and ecology of these animals. The formalin-preserved heart was examined first in situ, then measured and studied in detail. If the weight of the thick ...

The effects of valinomycin, an agent known to increase the K+ conductance (gK) of lipid bilayer membranes and to be an uncoupler of oxidative phosphorylation, were examined on young (3 days old) and old (15-19 days old) embryonic chick hearts. In the old hearts, valinomycin produced pronounced shortening of the ...

Para-methoxyamphetamine (PMA) and 3, 4-methylenedioxyamphetamine (MDA) both had potent stimulatory effects on mean arterial blood pressure and heart rate in the cat. These effects were antagonized by bretylium, a compound which blocks release of norepinephrine. The increases in heart rate were also antagonized by propranolol and the blood pressure increases ...

Oxidative phosphorylation was measured polarographically in mitochondria isolated from rat heart. With regard to ADP/O ratio and respiratory control index, no differences were found among mitochondria isolated from normal, acutely (increased pneumatic resistance of the heart-lung preparation) and chronicly (renal hypertension) stressed heart. However, the acute stressed heart induced by ...

Dopamine exerts marked positive inotropic effects in the dog with no effect on heart rate. This effect is abolished by propranolol, reduced by reserpine, and unaffected by atropine. Dopamine exhibits similar inotropic activity in the normal guinea pig and in guinea pigs with experimentally induced heart failure. In the isolated ...

From recent experiments it is indicated that in frogs living at +25 degrees C the abnormal response to cyanide anoxia appears as soon as 4-5 hr after the first isoproterenol (IPR) injection, but the aneurysm does not appear until a few hours after the second injection of IPR. There is ...

Chick embryos were used for analyzing the effect of isoproterenol on the embryonic heart. Isoproterenol (2 x 80 mg/kg in 48 hrs) was injected into the amniotic sac from the 5th embryonic day to the time of hatching. From the 5th to the 7th embryonic day (ed), transposition of great ...

Cytophotometric measurements of the DNA content of human heart muscle nuclei were performed on normal and congenitally malformed hearts of children. Congenital malformations of the heart lead to an early increase of the ploidy pattern as a sign of myocardial overload. This increase is significant. It starts, at the earliest, ...

Using the recipient's human heart removed at cardiac transplantation, the distribution of digoxin at both the cellular and subcellular level has been studied. In the presence of diffuse histological myocardial abnormalities tissue digoxin is decreased, but the subcellular distribution, presumably reflecting binding to a possible receptor site, is uniform. When ...

The effect of metabolic inhibitor, hypothermia (4 degrees C) and hyperbaric oxygenation (3 atm) on prolonging survival of the canine anoxic heart has been evaluated. Donor hearts were obtained from small mongrel dogs by giving the pre-cooled perfusate of 2 per cent magnesium sulfate (MgSO4), 5 per cent low molecular ...

A simulation of the function of the human heart and heart muscle has been developed in the form of a digital computer code. For a given set of values for the input variables, realistic values of the cardiac output variables are predicted. A detailed discussion of the simulation and some ...

In a survey in the Exeter area 139 patients with some degrees of abnormal atrioventricular conduction were notified by 282 family doctors. Per 100,000 of the population the prevalence of second-degree and thrid-degree heart block was estimated to be 17.3, of complete block past or present 15.6, and of complete ...

Until a few decades ago, yhe only instrumental information available to the cardiologist was the arterial blood pressure.

The pericardium presents a limiting or constricting action to acute dilatation of the heart. The diastolic pressure tends to approach the systolic pressure in a circulatory system distended with blood. The limiting action of the pericardium may be responsible for the small differences in the size of the heart noted ...

An α1-adrenergic receptor (α1-AR) antagonist increased heart failure in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), but it is unknown whether this adverse result was due to α1-AR inhibition or a nonspecific drug effect. We studied cardiac pressure overload in mice with double KO of the ...

1 To reduce load on the failing heart would seem likely to improve its performance, but it is remarkable that apparently adverse effects such as reduced filling pressure and arterial vasodilatation are so well tolerated.

1. The action of adrenaline on the K(+) balance of the isolated heart was found to depend on the ionic composition and the temperature of the perfusion fluids used.2. When the perfusion fluid contained 145 mM Na(+), 1.7 mM Ca(++) and 3-9 mM K(+), adrenaline caused the hearts to gain ...

A total of 4,486 widowers of 55 years of age and older have been followed up for nine years since the death of their wives in 1957. Of these 213 died during the first six months of bereavement, 40% above the expected rate for married men of the same age. ...

Isolated perfused rabbit hearts have been used to determine the reflection coefficients, sigma, of the heart capillaries to certain lipoid-insoluble substances. This was done by initially perfusing the heart with a Ringer solution containing no test molecule and then suddenly switching to a solution which differed from the original only ...

Bioelectric activity in single cells of the moth myocardium has been measured in situ with intracellular microelectrodes with particular reference to the bizarre ionic medium which bathes the tissues. Resting potentials averaged 47 mv, inside negative with respect to outside, despite a value of 11 mv calculated on the basis ...

The spatial dipole moment of a perfused animal heart suspended at the center of a fluid-filled sphere can be found in magnitude and direction to a good approximation by three sets of bipolar measurements. The method has been applied in finding the vectorcardiograms of turtle and rabbit hearts.

The pericardium presents a limiting or constricting action to acute dilatation of the heart. The diastolic pressure tends to approach the systolic pressure in a circulatory system distended with blood. The limiting action of the pericardium may be responsible for the small differences in the size of the heart noted ...