A strong genotoxic effect in mouse skin of a single painting of coal tar in hairless mice and in MutaMouse.

The dorsal skin of C3H/Tif/hr hairless mice was painted with coal tar, pharmacological grade. Epidermal cells and hepatocytes were isolated after 4, 24, 48 and 96 h and DNA strand breaks were determined as tail moment by the alkaline comet assay. The tail moment of epidermal cells was significantly greater at the time points 4, 24, 48 and 96 h after exposure compared to the controls, with the most DNA strand breaks at 24 h.

Nitrogen mustard-mediated mutagenesis in human T-lymphocytes in vitro.

The cytotoxic and mutagenic effect of the bifunctional alkylating agent nitrogen mustard (HN2) was examined. Primary human lymphocytes were exposed to graded doses of HN2 in vitro and relative survival was determined. Mutation induction at the hypoxanthine-guanine phosphoribosyltransferase (hprt) locus was measured by cloning the exposed T-cells in microtitre plates in the presence and absence of 6-thioguanine (TG).

Pitfalls in characterization of protein interactions using radioiodinated crosslinking reagents. Preparation and testing of a novel photochemical 125I-label transfer reagent.

Much attention has been focused on the study of protein interactions with radioiodinated photo-crosslinking reagents, and pitfalls in using this methodology are discussed. A new photochemical and cleavable heterobifunctional crosslinking reagent, succinimidyl N-14-(2-hydroxybenzoyl)-N-11-(4-azidobenzoyl)-9-oxo-8,11,14-triaza -4,5- dithiatetradecanoate (SHAD) was prepared, and its potential as a label transfer reagent was tested in model systems. SHAD was radioiodinated, and the labeled reagent (125I-SHAD) was converted to an amide (125I-HADM, as a mimicry of conjugation to protein 1) and photolyzed.

Interactions of plasminogen with polymerizing fibrin and its derivatives, monitored with a photoaffinity cross-linker and electron microscopy.

Localization of the plasminogen binding sites on fibrin has been difficult since these interactions occur on polymerizing fibrin, and studies with fragments can be misleading because of multiple carboxyl-terminal lysines that may bind to plasminogen. A hetero-functional photoaffinity cross-linker was used to study these interactions. Following attachment of the cross-linker to plasminogen in the dark, a clot was formed by addition of fibrinogen or fragment X and thrombin, and then the plasminogen was cross-linked to adjacent parts of fibrin by exposure to light.

Quantitative liver functions after administration of allyl alcohol to rats.

In rats a single dose of allyl alcohol (100 microliter per kg body weight) was given to produce periportal liver damage. Prothrombin index was reduced to a minimum after 12 hours and reestablished after 24 hours. The galactose elimination capacity was not changed.