Localization of99mTc in bone by means of autoradiography

The uptake of two different preparations of^99mTechnetium-methylene diphosphonate in fetal rat calvaria is compared. The localization of^99mTc after administration of^99mTc(Sn)-MDP and^99mTc-MDP showed equal distribution in autoradiography.     

Surface markers of a purified peritoneal eosinophil population from Mesocestoides corti-infected BALB/c male mice

Eosinophils of approximately 95% purity were prepared from the peritoneal cavities of BALB/c male mice infected with larval cestode, Mesocestoides corti. The alloantigenic surface marker phenotype of this cell population was shown to be H-2+Ly4+Ly5+Lyt-1-,2-,3-Ly-6-,7-Ia-Thy-1-TL-. Two of four anti-Lyt-2 sera were positive when tested on purified eosinophils by using the Staphylococcus aureus protein A sheep erythrocyte rosetting method, but absorption studies indicated that this reaction was not due to anti-Lyt-2 antibodies. Eosinophils are therefore Lyt-2-, although some Lyt-2 sera contain additional eosinophil reactive antibodies. A proportion (20 to 40%) of the population of eosinophils was positive for the Fc receptor, but all were negative for the C3 receptor and for surface immunoglobulin.     

The analysis of the joint effect of substances on reversion systems and the assessment of antimutagenicity.

The statistical methods for the analysis of mutagenicity and carcinogenicity underwent considerable theoretical-practical development following the need for assessing the mutagenic and carcinogenic potential of substances. Antimutagenicity is investigated through the analysis of respondents in dose-response assays, when two different molecules are administered separately and as a mixture to a respondent system. When the number of respondent units is high, and doses are orthogonal, it is possible to apply simple models such as analysis of variance. This is not always possible or common, and alternative approaches have been developed, based on multiple regression and on tables of proportions. In this work, some of the most frequently used methods for the assessment of joint responses are reviewed, particularly those based on multiple regression, such as the method of Shaeffer et al. and the method of Hass et al. In order to illustrate these methods, joint responses of perylene and cyclopentapyrene, of N-acetylcysteine and dinitropyrene, and of N-acetylcysteine and extracts from diesel exhausts were analyzed. An antagonistic effect of perylene on the action of CPP was detected by the algorithm of Shaeffer et al. The effect is not multiplicative, i.e., it is not proportional to the product of doses. The antimutagenic effect of N-acetylcysteine on dinitropyrene is multiplicative, as detected by the method of Hass et al. The latter reveals that the inhibition by N-acetylcysteine on the mutagenic effect of extracts from diesel exhausts is also multiplicative.