The respiratory costs of pyrene exposure and biotransformation were examined in isolated hepatocytes of adult rainbow trout, Oncorhynchus mykiss. Baseline oxygen consumption rates measured at an acclimation temperature of 7.5 degrees C and during an acute temperature increase to 15 degrees C were 10.1 +/- 0.1 and 22.6 +/- 0.4 ng O(2)/min/mg cells, respectively. Hepatocytes exposed to pyrene at ...

Cyclopenta(cd)pyrene (CPP), a polycyclic aromatic hydrocarbon without a bay region, is a potent bacterial mutagen. The experiments reported in this paper demonstrate that the major CPP metabolite generated by liver microsomes prepared from either phenobarbital or 3-methylcholanthrene pretreated rats is the optically active trans-3,4-dihydroxy-3,4-dihydrocyclopenta(cd)pyrene. Other experiments i...

Pyrene labelled Zn(2+)-cyclen 1 and bis-Zn(2+)-bis-cyclen 2 complexes were synthesized. The reversible coordination at physiological pH of Zn(2+)-cyclens to phosphate anions and to imide moieties, as present in thymine and uracil nucleotides, is well known. In the presence of analytes bearing a phosphate and an imide or two phosphate groups the formation of a ternary complex consisting of two p...

In this letter, we report the first observation of metal-enhanced excimer (P-type) fluorescence from pyrene. Pyrene in close proximity to silver island films (SIFs) shows enhanced pyrene excimer emission with a approximately 2.5-fold higher emission intensity observed from SIFs and 5x10(-3) M pyrene, as compared to a quartz control sample containing no silver nanoparticles. Our findings suggest...

A new class of fluorescent organogelators, pyrene-containing poly(arylene ether sulfone)s, showed two fluorescence switching modes in different gelation solvents. The THF gel exhibited excimer emission due to dimerization of the pyrene groups. In contrast, excimer emission was quenched after gelation in MC because of stacking among the pyrene groups.

While the equilibrium partitioning (EqP) method has been demonstrated to effectively predict adverse effects of nonionic organic chemicals in sediment on benthic organisms by toxicity tests, only a limited number studies have performed both water-only and whole-sediment tests using same species verified validity EqP-based assessment. To further examine EqP for application wide range hydrophobic...

Pyrene-containing compounds are commonly used in a number of fluorescence-based applications because they can form excited-state dimers (excimers) by stacking interaction between excited-state and ground-state monomers. Their usefulness arises from the facts that excimer formation requires close proximity between the pyrenes and that the excimer emission spectrum is very different from that of ...

Human exposure to chemical carcinogens is an important etiological factor in cancer diseases. In this article, we will discuss a new approach to the development of anticarcinogenic vaccines. The main task in our research was to select a benzo[a]pyrene immunomimetic peptide considered as a hapten-specific component. For this purpose, we synthesized carcinogen-protein conjugates and prepared mono...

The effects of chrysotile, water-leached chrysotile, and silica on microsomal metabolism of benzo(a)pyrene in vitro were studied. Examination of benzo(a)pyrene metabolites generated by 3-methylcholanthrene-pretreated rat liver microsomes, in the presence of chrysotile fibers, revealed a reduction in the overall metabolism of the hydrocarbon. Thus, chrysotile appeared to modify the activities of...

We propose that the cellular burden of certain carcinogens may be mitigated by P-glycoprotein (P-gp), the putative drug efflux pump. In a series of multidrug resistant human breast cancer MCF-7 cells with increasing P-gp expression we examined this hypothesis using benzo(alpha)pyrene, a widely distributed environmental and dietary carcinogen. We found that multidrug resistant cells were cross-r...