Eugene A. Stead

An Error in Measuring Changes in Plasma Volume After Exercise

Summary When the dye method is used for measuring changes in plasma volume after exercise, an error occurs due to changes in the optical properties of the serum.

Capillary Tube Kjeldahl Method for Determining Protein Content of 5 to 20 Milligrams of Tissue Fluid

Summary A technic is given for obtaining 5 to 20 mg of subcutaneous fluid in subjects with minimal edema. A capillary tube Kjeldahl method for determining the protein content of small amounts of edema fluid is described.

Factors influencing the auricular murmur and the intensity of the first heart sound

Abstract Studies of cases of mitral stenosis in which there were varying degrees of heart block have clearly demonstrated that the presystolic murmur of mitral stenosis is produced by contraction of the auricle. 1, 2, 3 More recently it has been appreciated that presystolic gallop rhythm and certain split heart sounds also result from sound waves initiated by auricular contraction. 4, 5 The relation of the auricular contraction to the intensity of the first heart sound has been investigated by many observers. 6, 7, 8 There has been no unanimity of opinion, however, as to the mechanism by which the auricular contraction modifies the intensity of the first sound. This study is reported for the purpose of emphasizing: (1) the effect of the degree of ventricular filling on the intensity of the sound produced by the auricular contraction; (2) the relative effect on the intensity of the first heart sound of (a) the time of auricular contraction and (b) the degree of ventricular filling.