ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

An attempt is made to describe the nature of the chemical interactions participating in blood clotting. In the laboratory, thrombin can be derived directly from prothrombin without the physiologic activators calcium, thromboplastin, Ac-globulin, and platelet derivatives. The newly recognized clotting factor, Ac-globulin, is essential for normal physiologic hemostasis. Plasma Ac-globulin concentration decreases in experimental liver damage, temporarily with dicumarol administration and may increase from high doses of aminophylline. In citrated storage plasma it is stable for a week but not in oxalated human plasma. Compared with other species, human plasma contains a low concentration of Ac-globulin. Methods for Ac-globulin analysis have been developed; perhaps more important is the fact that the two-stage method for prothrombin analysis need no longer be considered a complicated procedure.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

Animal experiments were done to learn the degree of coronary narrowing required to produce the larger intercoronary collateral channels, their speed of development, and the degree of protection afforded the myocardium. Twelve or more days of 75 per cent narrowing were required to produce sufficiently rich anastomotic communications to protect the myocardium from damage, and to permit survival after superimposed acute complete occlusion. The physiologic and pathologic significance of the intercoronary collateral communications and the clinical implications in coronary artery disease are discussed.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

A review is presented of 107 cases of paroxysmal ventricular tachycardia. In the majority it was associated with acute coronary thrombosis or coronary sclerosis, in some with rheumatic valvular disease, and in others with no organic heart disease. It is generally critical and demands careful attention. Occasional cases are overlooked because only one heart sound is present for each cardiac cycle and the heart rate is misjudged to be one-half the actual rate. The outlook often is serious if the condition is not effectively treated. Therapy generally is successful in controlling the arrhythmia. The most valuable drug is quinidine. Other medications are magnesium sulfate, atropine, potassium salts, and possibly morphine.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

Coarctation of the aorta can be recognized in most instances by simple findings of physical examination. The anomaly is one which carries a variable prognosis. The condition may be tolerated through a long life with little incapacitation or may be accompanied by early and serious complications in the form of cardiac failure, aortic rupture, or intracranial hemorrhage. In a high percentage of patients it is possible to remove the aortic block and establish a pathway of satisfactory size. A series of cases shows that there is an excellent chance of relieving hypertension by such surgery. Mortality rates for these operations have not been unduly high. Certain complicated types of cases carry too high a risk and should not be accepted for surgery.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

Effects of changes in posture upon plethysmogram and skin temperature are investigated. Since posture, by altering venous return, affects pulse volume and response of digital volume and skin temperature to procedures releasing sympathetic tone, these should not be interpreted solely in terms of arterial blood flow. In the normal elevated limb, e.g., the skin temperature response to body heating simulates organic arterial disease. The clinical significance of these findings is discussed with particular reference to interpretation of skin temperature readings, the diagnosis of thromboantiitis obliterans, indications for sympathectomy in poliomyelitis, the management of the edematous limb and other conditions.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

The dilution curve of the specific activity of the erythrocytes in the arterial blood after intravenous injection of labeled erythrocytes with P32has been treated mathematically. It is possible with the help of the dilution curve to calculate the minute volume of the heart and the thoracic pool (the residual blood of the heart + the blood content of the lungs). The values of the thoracic pool amount to about 30 per cent of the total circulatory blood-volume.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

The electrical position of the heart with reference to the electrodes used in studying its field is unknown. For reasons presented, it is more likely eccentric; hence, the equation defining the field of an eccentric dipole in a spherical medium might be useful for projected experimental studies and for better understanding of the way in which a given electrical position determines the electrode potentials. A method introduced by Helmholtz was used for deriving the desired equation. It is discussed since its concepts are of considerable importance to other electrocardiographic problems, too. The more simple mathematical example dealing with the centric dipole in the sphere is discussed. The equation for the field of the eccentric dipole is given and data based upon it are presented in numerical and map form. The Helmholtz equation for the field in the spherical conductor produced by two small spherical electrodes arbitrarily located is also presented and briefly discussed.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

This critical study of atrophy of the heart is based upon a detailed analysis of 85 proved cases. The clinical, roentgenographic and electrocardiographic features are considered to be sufficiently distinctive to facilitate antemortem recognition. The clinical implications of atrophy of the heart and the reversibility of atrophy and hypertrophy are emphasized.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID

摘要:

Clinical experience has not confirmed previous observations that intravenous injection of vitamin C and intramuscular injection of histidine monohydrochloride are useful in the treatment of peripheral ischemia observed in arteriosclerosis obliterans. Clinical experience with intravenous injection of ether has failed to indicate that this method of treatment is of value in improving the peripheral arterial circulation in thrombo-angiitis obliterans and arteriosclerosis obliterans.

ISSN:0009-7322    

出版商:OVID    

年代:1950

数据来源: OVID