ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

Relationships between artefacts in recorded intracardiac pulses and the dynamic response and susceptibility of catheter-manometer systems to artefacts caused by motion of the catheter were investigated. Sine-wave motions of the catheter, resembling motion frequently seen when the catheter is in the pulmonary artery, produce sine-wave pressure variations with peak-to-peak amplitudes of 10 mm. Hg. Square-wave motions (impacts) produce high-frequency pressure variations, greatest (10 to 200 mm. Hg) when directed along the axis and much less when perpendicular to the axis of the catheter. High-fidelity records of pressure by conventional cardiac catheter-manometer systems are most unlikely when such catheters are threaded through the beating heart.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

A state of shock followed the acute reduction of cardiac output caused by injection of a necrotizing solution into the myocardium. Decrease in blood pressure, decrease in circulating plasma volume, increase in hematocrit readings and the effect of re-expansion of the plasma volume established the similarity of this state to other forms of shock. Pulmonary blood volume decreased concurrently with cardiac output and effective plasma volume.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

This report deals with the relationship of various lipid fractions in the heart and in the liver, and the urinary excretion of ketone bodies, to sex and body weight in normal nonfasted albino rats. Results indicate the existence of differences in concentrations of fatty acid, neutral fat, and phospholipid in the liver of male rats as body weight increases. Phospholipid concentration of the liver and heart of the male and the heart of the female declines significantly with age.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

A pump of 50 cc. reservoir capacity, only 10 cm. in diameter, was placed in the systemic circuit between the left auricular appendage and the left common carotid artery in each of 10 dogs so that the systemic circulation was maintained by the pump during complete cardiac arrest resulting from experimentally produced ventricular fibrillation. All dogs recovered completely.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

Left main coronary artery blood flow, cardiac output and pressures in the pulmonary artery, the aorta and both atria were continuously recorded in the dog. Restriction of left coronary flow increased left atrial pressure substantially, but right atrial pressure only slightly; left ventricular work, cardiac output and arterial pressure fell markedly. During restriction of left coronary flow, the left ventricular function curve (modified Starling curve), which does not normally show a descending limb even at high filling pressures, developed a pronounced descending limb. Unilateral ventricular failure was demonstrated.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

The ability of the right ventricle to compensate as the pulmonary artery is constricted appears to be determined by four major factors: (1) there occurs the well-known increased force of contraction as the right heart becomes distended; (2) the adequacy of the coronary circulation determines to a great extent the Degrees of pulmonary arterial constriction which can occur before failure occurs; (3) the circulatory reflexes apparently aid the compensation to a moderate extent; and (4) the greater the blood volume, the greater is the limit of compensation before right ventricular failure occurs.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

Electric impedance plethysmography has been offered as a substitute for mechanical plethysmography and would be particularly suitable for regions in which the mechanical method cannot be applied. A comparative investigation of mechanical and impedance plethysmograms, taken simultaneously from a finger or a forearm, revealed that, while the normal pulsations were reproduced reasonably well, electric impedance plethysmography cannot be employed to determine volume changes following venous occlusion. The reasons are discussed.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

The hydrocarbon squalene, which has been suggested as a precursor in the biosynthesis of cholesterol, was fed to rabbits to see whether cholesterol thus synthesized would be efficacious in producing atheromatous lesions. Rabbits on a 3 per cent squalene diet for seven weeks showed an increase in liver weight and liver nonsaponifiable material but no more atheroma than did controls. Animals on the same diet for 14 weeks showed an increase in the cholesterol-rich lipoproteins as determined in the ultracentrifuge. Addition of squalene in no way altered the atherogenic propensities of the cholesterol diet.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID

摘要:

A detailed thermodynamic study of isolated strips of dog aorta is basic to the interpretation of the nonlinear and apparently rubber-like elastic behavior of such specimens. Experimental data indicate that the retractile force in isolated aortic strips of the dog is entropic. Volume changes with elongation in such strips are negligible. However, a large negative internal energy contribution to the total force is present at small elongations. Studies of aortic strips extracted with alkali suggest that the latter force arises from the elastic tissue itself.

ISSN:0009-7330    

出版商:OVID    

年代:1954

数据来源: OVID