Chicken cathelicidin-2-derived peptides with enhanced immunomodulatory and antibacterial activities against biological warfare agents.

Host defence peptides (HDPs) are considered to be excellent candidates for the development of novel therapeutic agents. Recently, it was demonstrated that the peptide C1-15, an N-terminal segment of chicken HDP cathelicidin-2, exhibits potent antibacterial activity while lacking cytotoxicity towards eukaryotic cells. In the present study, we report that C1-15 is active against bacteria such as Bacillus anthracis and Yersinia pestis that may potentially be used by bioterrorists.

An immunochemical assay to detect DNA damage in bovine sperm.

An immunochemical assay has been developed to detect oxidative damage in bovine sperm DNA. Sperm DNA contains a large amount of oxidative damage as a result of exposure to exogenous agents, but damage also can caused by normal metabolic processes and the absence of DNA repair in the later stages of spermatogenesis. A freeze-thaw procedure performed on extended bovine sperm in straws did not induce additional DNA damage immediately after thawing compared with nonfrozen extended sperm.

Toxicokinetics of sulfur mustard and its DNA-adducts in the hairless guinea pig.

In order to provide a quantitative basis for pretreatment and therapy of intoxications with sulfur mustard (SM) the toxicokinetics of this agent as well as its major DNA-adduct were studied in male hairless guinea pigs for the intravenous, respiratory and percutaneous routes. The study comprised measurement of the concentration-time course of SM in blood and measurement of the concentrations of intact SM and its adduct to guanine in various tissues at several time points after administration of, or exposure to SM. SM was analyzed in blood and tissues by gas chromatography with automated thermodesorption injection and mass-spectrometric detection.

The formation and repair of cisplatin-DNA adducts in wild-type and cisplatin-resistant L1210 cells: comparison of immunocytochemical determination with detection in isolated DNA.

We have studied the formation and repair of cisplatin-DNA adducts in wild-type mouse leukemia L1210/0 cells and in the sublines L1210/2 and L1210/5, which differ in cisplatin sensitivity. In a colony-formation assay these sublines were 9- and 22-fold more resistant compared to L1210/0, respectively. Cisplatin-induced DNA modification was studied at the cellular level by immunocytochemistry with antiserum NKI-A59 raised against cisplatin-treated DNA.

Cisplatin-DNA adducts and protein-bound platinum in blood of testicular cancer patients.

DNA adducts formed by cisplatin [cis-diamminedichloroplatinum(II)] were measured in blood samples from 48 testicular cancer patients treated in four centers in Europe during four to six cycles with cisplatin infusions on five successive days (total samples, 112). Total protein-bound platinum (Pt) in blood was also measured (total samples, 84). The mean on the main DNA adduct, cis-Pt(NH3)2d(pGpG) (Pt-GG), was 0.

The formation and persistence of carboplatin-DNA adducts in rats.

The formation and persistence of platinum-DNA adducts were studied with immuno(cyto)chemical methods in male and female Sprague-Dawley rats treated with a single i.p. dose of carboplatin.

Cisplatin- and carboplatin-DNA adducts: is PT-AG the cytotoxic lesion?

In order to determine the nature of the cytotoxic lesion(s) formed by the antitumour drugs cisplatin and carboplatin, a comparative study was made of bifunctional DNA-adduct formation by these drugs. The kinetics of bifunctional cisplatin adduct formation were studied with DNA in vitro and in cultured Chinese hamster ovary (CHO) cells. Prior to adduct measurements with AAS in in vitro platinated DNA and with ELISA in cellular DNA, the monoadducts were inactivated with thiourea (10 mM; 1 h at 37 degrees C).

Formation of DNA adducts by the anticancer drug carboplatin: different nucleotide sequence preferences in vitro and in cells.

We have studied the formation of adducts upon carboplatin treatment of isolated DNA and in cells. The major adduct formed in vitro, determined with atomic absorption spectroscopy and enzyme-linked immunosorbent assay, was the intrastrand cross-link cis-Pt(NH3)2d(pGpG)(Pt-GG) (58%). cis-Pt-(NH3)2d(pApG) (Pt-AG) (11%), cis-Pt(NH3)2d(GMP)2 (G-Pt-G) (9%), and monofunctionally bound platinum (cis-Pt(NH3)3dGMP (Pt-G), 22%) were formed in smaller amounts.

Effects of thiourea and ammonium bicarbonate on the formation and stability of bifunctional cisplatin-DNA adducts: consequences for the accurate quantification of adducts in (cellular) DNA.

Cisplatin reacts with DNA by forming mainly bifunctional adducts via reactive monofunctional intermediates. When freshly platinated DNA was postincubated with thiourea (10 mM, at 23 or 37 degrees C) for periods of up to 24 h, followed by determination of mono- and diadducts, a rapid initial decrease was seen in the fraction of diadducts, followed by a much slower decrease. About 40% diadducts were found after 10-min postincubation at 23 degrees C, which dropped to some 14% after 24 h at 37 degrees C; total platination was hardly affected.

Kinetics of the formation and removal of cisplatin-DNA adducts in blood cells and tumor tissue of cancer patients receiving chemotherapy: comparison with in vitro adduct formation.

During chemotherapy with a cisplatin-containing combination of drugs, 217 blood samples from 30 cancer patients were analyzed for the presence of the main cisplatin-DNA adduct cis-Pt(NH3)2d(pGpG) (Pt-GG). Cisplatin was administered during 3-h infusions on each of 5 consecutive days, resulting in increasing adduct levels which, on the average, were about twice as high after the fifth as after the first infusion. Higher levels were found in blood samples of patients who received the same total amount of cisplatin in one single 3-h infusion.