The tagging of red cells and plasma proteins with radioactive chromium

Complications of heart valve replacement. Embolism bleeding and hemolysis

Fifty-two patients surviving single heart valve replacement since September 1962 were reviewed in order to detail the incidence of post-operative embolism, bleeding and hemolysis. A substantial decrease in the occurrence of embolism has been seen with newer prosthetic devices paralleling the improvement in cardiac catheterization dynamics. The frequency of embolism appears also to be affected by the degree and adequacy of anticoagulant control although a higher morbidity from bleeding must be accepted. The tendency to deformation and destruction of red cells by rigid prosthetic valves is apparent since shortened red cell survival indicative of hemolysis was found in all patients studied. Hemolytic anemia of importance was uncommon.

Use of 125-I- and 51-Cr-labeled albumin for the measurement of gastrointestinal and total albumin catabolism

A method for the simultaneous measurement of gastrointestinal protein loss and total albumin turnover entailing the use of a combination of (125)iodine- and (51)chromium-labeled albumin is described. Albumin turnover was calculated by the measurement of albumin-(125)I plasma decay and cumulative urinary excretion, and the results obtained agreed closely with previous studies utilizing albumin-(131)I. Gastrointestinal catabolism was calculated from the rate of fecal excretion of (51)Cr and the specific activity of plasma albumin-(51)Cr, and these data were related to the calculated albumin turnover results. During the period of 6-14 days after administration, the ratio of specific activties of albumin-(125)I and -(51)Cr in plasma and in extravascular spaces or gastric and biliary secretions remained almost identical. Fecal excretion of (51)Cr was also quite stable at this time. In six normal subjects gastrointestinal catabolism accounted for less than 10% of total albumin catabolism. Excessive gastrointestinal protein losses did not contribute to the low serum albumin in three patients with cirrhosis or in two adults with the nephrotic syndrome. Multiple mechanisms leading to hypoalbuminemia were demonstrated in other subjects with a variety of gastrointestinal disorders.

Uptake of 51Cr as an indicator of metabolic change in wheat root tips

A consistent pattern of51Cr incorporation was observed in serial sections of the roots of two varieties of wheat, both vernalized and unvernalized. The changed metabolic state attendant on vernalization was reflected by a higher level of51Cr incorporation. A clear indication was given that51Cr uptake can be used as a sensitive indicator of metabolic change in wheat root tips.The mode of entry and binding of the trivalent and hexavalent forms of chromium was also investigated.

Red blood cell survival in patients with aortic valvular disease and ball-valve prostheses

Red blood cell survival was determined in patients with aortic valvular disease, postoperative patients with aortic valvular ball-valve prostheses and postoperative patients with multiple ball-valve prostheses. The red blood cell survival was reduced in the majority of patients in each group when compared with the red blood cell survival from a normal control group.

A detailed analysis of the survival curves suggested that in many patients there was more than one population of red blood cells. The first population displayed rapid random destruction. This population was not present in normal persons in the control group. The second population showed the usual decline in radioactivity due to random destruction and loss of the red cell label due to elution. The shortened red blood cell survival in some patients was due to a large percentage of the first population of randomly destroyed red blood cells, in other patients to an accelerated rate of destruction of the usual single population of cells while others had a combination of the two mechanisms.

A mechanism of mechanical hemolysis due to increased intracardiac turbulence was suggested as a cause for the shortened survival. When the turbulence was increased by a leak around the aortic or mitral valve prosthesis the red blood cell survival was found to be further decreased. In some cases this reduction in survival was enough to produce hemolytic anemia.

The Coombs antiglobulin test was positive in three patients. The suggestion was made that the development of autoantibodies to red blood cells was secondary to increased destruction of red blood cells.