Ben I. Friedman

Deoxycytidine in Urine of Humans after Whole-Body Irradiation

Increased levels of deoxycytidine were found in the urine of two humans during the first 24 hours after irradiation. This substance presumably was produced by the break-down of DNA following irradiation, or resulted from interference with the synthesis of DNA.

Radiation-Induced Urinary Excretion of Deoxycytidine by Rats and Humans

Since the discovery by Pařizek et al. (1) of increased urinary excretion of deoxycytidine (CdR) by rats following total-body x radiation, much attention has been focused on the possibility of using CdR-uria to estimate the degree of radiation injury in animals, especially in humans. In our laboratory, urinary excretion of milligram quantities of CdR was demonstrated in two cancer patients within twenty-four hours after they received total-body doses of about 250 rads, while CdR was not detected in specimens collected before irradiation (2). On the other hand, Arients group in Czechoslovakia, which has been very active in this field of study, recently reported urinary excretion of only microgram quantities of CdR in the 24-hour postirradiation urine obtained from an acute paramyeloblastic leukemia patient treated with a total-body single dose of 280 rads (3). In both studies, a microbiological assay was employed to estimate the amount of CdR excreted in the urine. This discrepancy in the human results pro...

Colorimetric analysis of deoxycytidine in urine after separation by ion-exchange column chromatography

Abstract A rapid and sensitive colorimetric determination of deoxycytidine in urine has been described which can detect as little as 4 × 10 −3 μmole of deoxycytidine in 10 ml of urine. Deoxycytidine in urine is separated from other compounds containing 2-deoxyribose by successive treatment with cation- and anion-exchange columns. Deoxycytidine-2- 14 C is added to each sample to estimate the loss of endogenous deoxycytidine during the purification process. Average recovery of deoxycytidine is 94 ± 4%. The partially purified fraction containing deoxycytidine is hydrolyzed in 5 × 10 −3 N HCl in a boiling water bath for 130 min and the amount of 2-deoxyribose released is measured with the use of the malonaldehyde-thiobarbituric acid reaction. Under these conditions deoxycytidine is hydrolyzed completely but 20% of the 2-deoxyribose released is degraded.

The Relationship between Radiographic Findings and Asymmetrical Radioactivity in the Shoulder

A prospective study was performed to compare asymmetrical radioactivity in the shoulder on 99mTc bone scans with the conventional radiographic findings of 100 right-handed and 8 left-handed patients. Of the 100 right-handed patients, 30 had increased radioactivity in the right shoulder; 5 showed increased radioactivity on the left. Clinical history, shoulder physical examination, and site of injection did not influence the frequency of asymmetrical radioactivity; only dominant handedness correlated with this finding.

Scintillation Camera Imaging of Post Renal Transplantation Ureteral Death: A Case Report

In the case presented, the death of the donor ureter in a homotransplanted kidney was visualized by scintillation camera studies. Radioactivity accumulated in a bulge proximal to the necrotic segment with none seen in the distal ureter or bladder. The diagnosis of ureteral necrosis was confirmed at surgery.