(131)I-Lym-1 induced durable remissions in patients with NHL resistant to chemotherapy and was associated with acceptable toxicity. The nonmyeloablative MTD for each of the first two doses of (131)I-Lym-1 was 100 mCi/m2 (total, 200 mCi/m2) (3.7 GBq/m2; total, 7.4 GBq/m2).

Background. The development of new chelating agents and radiolabeling protocols is essential to progress in radioimmunotherapy with antibody‐chelate conjugates. Methods. Immunoconjugates of four polyazamacrocycles with N‐bonded acetate groups were prepared by conjugation via 2‐iminothiolane to Lym‐1, a murine antilymphoma immunoglobulin G2a MoAb. To optimize 67Cu radiolabeling, complexation conditions were explored. The kinetic stabilities in vitro in human serum of four 67Cu labeled immunoconjugates were investigated. Results. Lym‐1‐2IT‐6‐BAT‐67Cu, the chelate conjugate of 6‐[p‐(bromoacetamido)benzyl]‐1,4,8,11‐tetraaza‐cyclotetradecane‐N,N′,N″N″‐tetraacetic acid, exhibited excellent kinetic stability in human serum, while Lym‐1‐2IT‐2‐BAT‐67Cu, prepared from the structural isomer 2‐[p‐(bromoacetamido)benzyl]‐1,4,8,11‐tetraazacyclotetradecane‐N,N′,N″,N″‐tetraacetic acid, exhibited a markedly higher rate of loss of radiometal. It was observed that the radiolabeling ratio of Lym‐1‐2IT‐6‐BAT‐67Cu, in mCi per mg immunoconjugate, was limited solely by the specific activity of the radiometal, which varied significantly from lot to lot. This ratio for a given lot of 67Cu can be predicted by a preliminary titration. Conclusions. The preparation of 67Cu labeled immunoconjugates of therapeutic quality has been improved by the determination of optimum radiolabeling conditions, and by development of a titration protocol which rapidly and accurately predicts the radiolabeling ratio in mCi per mg immunoconjugate. The surprising difference in the properties of 6‐BAT and 2‐BAT shows the exquisite dependence of kinetic stability on structure. Cancer 1994; 73:779–86.

Background. BrE‐3 is a monoclonal antibody that has promise for imaging and therapy of human adenocarcinoma. Because of observations in therapeutic trials of yttrium‐90 (90Y) escape from radioimmunoconjugates and uptake by the skeleton with resultant bone marrow toxicity, the authors attempted to evaluate the importance of this factor by a comparison of the LD50 in healthy mice treated with 90Y that had been chelated with either of two high affinity chelators, methylbenzyldiethylene‐triaminepentaacetic acid (MX‐DTPA) or bromoacetamidobenzyl‐1,4,7,10‐tetraazocyclododecane‐N,N′,N″,N″‐tetraacetic acid (BAD). Methods and Results. Bone marrow hematopoietic toxicity was dose‐limiting and the source of death for both chelators. The LD50 for 90Y‐BrE‐3‐MX‐DTPA was 220.9 μCi, and that for 90Y‐BrE‐3‐2IT‐BAD was 307.8 μCi. Whole‐body autoradiography revealed substantially greater uptake of 90Y in the skeleton when MX‐DTPA was used as the chelator. Conclusions. These observations suggest that 90Y escape to bone is a significant factor in the maximum tolerated dose of radioimmunoconjugate that can be used in therapeutic trials. These results probably underestimate the importance of 90Y escape since 90Y in the skeleton of patients is likely to be more significant than in mice because more of the 90Y energy is absorbed in the marrow of larger species. Cancer 1994 73:1012–22.

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This study aimed at assessing qualitatively and quantitatively the ability of Nigerian mothers to prepare salt-sugar solutions (SSS) (according to the Nigerian standard formula) under the usual home environment. Mothers were provided with the ingredients but not with measurement spoons nor containers. 274 mothers randomly selected from a peri-urban community participated in the study. Of the 192 (70.1%) who claimed knowledge on SSS preparation, only 47 (24.5%) gave a correct description of its constitution and 103 (54.2%) were willing to prepare the solution. Of the 103 who prepared the solution, 34 (33.0%) used the correct number of teaspoons of salt and of sugar. The composition of the solutions prepared by the mothers varied greatly with sodium levels ranging from 0-760 mmols/l (mean 225.8 +/- 155.3, median 177.3) and glucose, 0-262.6 mmols/l (mean 68.7 +/- 54.4, median 52.0). Only 7 mothers (6.8%) prepared solutions with acceptable sodium and glucose levels. It is concluded that salt-sugar solutions prepared by Nigerian mothers are not safe. There is a great need to review the oral rehydration therapy (ORT) promotion strategies and messages in order to avoid the dangers associated with improperly constituted solutions.