Biological spin trapping. II. Toxicity of nitrone spin traps: dose-ranging in the rat.

To obtain the strongest possible free radical spin adduct signal using the electron paramagnetic resonance spectroscopy-spin trapping technique, it is desirable to load an animal with the highest dose of spin trap possible. One hundred and twenty six male Sprague-Dawley rats were used to establish the toxic dose range for PBN (alpha-phenyl N-tert butyl nitrone) and 18 other similar spin traps. The lethal dose of PBN was found to be approximately 100 mg/100 g BW (0.564 mmol/100 g. The 18 other compounds were then tested, and their toxicities were gauged in terms of molar equivalents to PBN. Of these spin traps, DMPO (5,5-dimethyl-1-pyrroline-N-oxide) was found to be the least toxic (no toxic signs at twice the lethal dose for PBN) while 2,6-difluoro-PBN and M4PO (3,3,5,5-tetramethyl-1-pyrroline-N-oxide) were the most toxic, both causing death at one eighth the PBN-equivalent lethal dose. Nine of the 18 nitrones appeared non-toxic at the 0.25 PBN-equivalent lethal dose level.

Intrafamily decision making in family planning.

PIP: 58 expectant couples were counseled about family planning postpartum and husbands and wives were asked to rank preference of methods. Husbands preferred IUDs (12%), the pill (7.6%), or diaphragms (8.2%). Wives preferred diaphragm (10%), foam (8%), jelly (8%), and IUDs (6%). The process of discussion was then charted. It was found that wives were more influential than husbands in the joint ranking process, which put IUDs 1st, followed by diaphragms and jelly. As discussion progressed, side effects became more important and the condom was selected as a compromise more often than any other method. It is suggested that marketing attempts for condoms emphasize the lack of side effects as well as promote the advantages to men.^ieng