The use of human albumin millimicrospheres tagged with 99mTc in the evaluation of the removal capacity of the reticuloendothelial system

Abstract

Liver uptake kinetics of 99mTc labelled millimicrospheres of human serum albumin (MM) was studied in 16 subjects. Every subject received four doses of MM intravenously. The uptake constant decreased progressively with increasing dose. The maximum liver removal capacity, a parameter which is independent of liver blood flow, was calculated according to the method of Iio and Wagner (1963). From these data we conclude that MM are taken up by the reticuloendothelial system (RES) with saturable kinetics, and they are suitable for clinical use to evaluate RES function in man.

Preparation of technetium-99 m human albumin nanospheres for use in the measurement of reticuloendothelial clearance capacity

“…As approximately 90-95% of this clearance is by the liver, the technique is predominantly a measure of the phagocytic capacity of the liver. 5 The technique involves injecting a dose of radiolabelled particles intravenously, withdrawing venous blood samples at time intervals and calculating the clearance rate from the measurement of the radioactivity of each sample. Radiolabelled particles are used widely in nuclear medicine for imaging of the bone marrow, liver, lung, lymph nodes and spleen.…”

Blood Clearance and Organ Distribution of Intravenously Administered Polystyrene Microspheres of Different Sizes

“…To this end, numerous investigations have been reported on the organ distribution of polymer microspheres: polystyrene [1][2][3][4][5][6], polycyanoacrylate [7][8][9][10], serum albumin [11][12][13][14], starch [15,16], acrylic polymers [17,18], and poly(glycolic acid) microspheres [19]. In addition, liposomes [20] and carbon particles [21] were examined as drug carriers.…”

Reticuloendothelial System Activity and Organ Failure in Patients With Multiple Injuries

“…26 Moreover, clinical studies have found no correlation between hepatic blood flow and the removal constant of radioactive tracer. 25 Nevertheless, we tried to account for the possible effects of impaired liver blood flow and performed an ICG test parallel to the measurements of RES function in all patients. The ICG test is a well-established method for evaluation of liver blood flow.…”

“…The method we used to evaluate RES function is reliable [24][25][26][27] and has been used in previous experimental investigations. 30 In a previous study undertaken at our hospital, this method was able to assess the alterations of RES function in liver transplant recipients.…”

“…[24][25][26][27] A fresh preparation of 100 MBq (2.7 mCi) of technetium Tc 99m bound to human albumin was obtained to measure RES clearance capacity and was administered as an intravenous bolus into the central venous catheter. For serial measurements at comparable body areas, after verification of both liver lobes by ultrasound, portable Geiger-Mü ller counters were placed on each lobe, at the center ofthe aorta, on the heart, and across the right lung.…”