99m Tc-nanocolloid Research Articles

Technetium-99 m nanocolloid for the scintigraphic assessment of inflammatory bowel disease in the colon: its value in comparison with Indium-111-labelled granulocytes

The usefulness of 99m Tc-nanocolloid for the assessment of localization and disease activity of colitis in patients suffering from inflammatory bowel disease (IBD) was investigated in 10 patients. Results of 99m Tc-nanocolloid scintigraphy were compared with Indium-111 autologous granulocyte scintigraphy and the activity index according to Van Hees. In none of the patients a true positive result of the 99m Tc-nanocolloid scintigraphy was encountered, while 111In-granulocyte scintigraphy was positive in 7 of 10 patients with active disease. Radioactivity became visible in the small bowel starting 2 h after injection of 99m Tc-nanocolloid most likely because of excretion by the liver of degradation products of the radiopharmaceutical. The authors conclude that despite a previous communication 99m Tc-nanocolloid cannot replace 111In-granulocytes for the assessment of IBD patients with active colitis.

Phagocytosis by macrophages in zinc-deficient rats

Phagocytosis by polymorphonuclear cells has been found to be significantly reduced in zinc-deficient patients and this finding was confirmed in animal experiments. In order to find out whether phagocytosis by macrophages is similarly altered, experiments were conducted in three groups of 18 rats. Control, zinc-deficient and pair-fed rats were given 99mTc nanocolloid intravenously. In ten other experiments (5 experimental and 5 control rats) 99mTc-sulfur colloid was injected intravenously. The biodistribution was determined by a well-type gamma counter and the results were evaluated statistically. The greatest amount of radioactivity was taken up by the liver, followed by the spleen, lung and kidney. In both series of experiments however the zinc-deficient animals appeared to take up a greater amount of the radiotracer ( P < 0.05).