A method for estimating blood ammonia

A reliable and simple method for estimating blood ammonia levels is described. It is based on the phenolate/hypochlorite colorimetric method and has been found to be sensitive and reproducible. (AU)

An index for the measurement of the degree of aortic incompetence

It has been noted that under certain conditions a standard sphygmomanometer cuff may act as a valve on the peripheral blood vessles. A pneumatic cuff was employed as a valve on the brachial artery in aortic incompetence, and by obstructing the regurgitant blood a means for measuring its volume was devised. The principle on which this method is based is that of using a special type of sphygmomanometer cuff which at certain pressures exerts a valve-like action on the brachial artery. In aortic incompetence the cuff prevents some of the backward flow, thus increasing the foreward flow. This increase in foreward flow, measured plethysmographically, is used as a basis for calculating indices of regurgitation. The essential feature of this technique is the measurement of forearm-hand blood flows by venous occlusion plethysmography with the limb in the upward and vertical position, and at high ambient temperatures of 30 to 32 oC. A high degree of regurgitation may be indicated by this technic (Summary)

A report on investigations designed to measure an index of the hardness of arteries in vivo and in situ

It was considered that if means could be devised which measured the compressibility and distensibility of the arteries in vivo it might be possible to measure those changes which are generally designated as hardening. It is proposed in this communication to deal with the first of these two factors, that is , compressibility. The key to the measurement of the compressibility of the arteries was a technique which provides a measurement of the resistance to flow through the larger arterial vessels. This arterial flow measurement was used to provide an index of the degree of collapse of the brachial artery when various external pressures were applied. This technique will be described and a preliminary report on the use of this record on those subjects which were clinically designated as having hardened arteries (AU)

The protein content of liver and muscle as a measure of protein deficiency in human subjects

The major nutritional problem in underdeveloped countries is deficiency of protein. At the present time there is no way of assessing with any accuracy the degree to which a human being is depleted of protein.Until this gap in scientific and medical knowledge is filled, it will be difficult to plan preventive measures in the most effective way. In clinical work the problem becomes one of finding some objective measure that will indicate the severity of malnutrition. With this aim analyses have been made of biopsy and autopsy specimens of the liver from malnourished children. The degree of fatty infiltration of the liver seems to be of little importance. There is a large loss of liver protein, which however, shows no clear relation to the general condition of the patient. It is suggested that in chronic malnutrition the main loss of protein is from muscle, rather than from liver. This is confirmed by the results of preliminary measurements on fatal cases. Measurement of the protein depletion of the tissues may provide a baseline for assessing the value of simpler tests, of the kind that can be applied in the field. (AU)