Misonidazole (MIS) is a hypoxic cell radiosensitizer currently undergoing Phase III clinical trials in the treatment of cancer by radiation. It is also a cytotoxic agent with specificity toward hypoxic cells, and consequently has a tumoricidal effect in laboratory animals. This tumoricidal effect has not been clinically applicable, in part because the initial resistance to the cytotoxic action ...

The in vitro effects of metronidazole on the production of reactive oxygen species by polymorphonuclear (PMN) cells were studied by means of nitroblue tetrazolium and luminol-dependent chemiluminescence. At therapeutic doses of metronidazole (4.98-24.86 microg/mL) significant inhibition of the production of reactive oxygen species was noted in both methods. The inhibitory effect was in a dose-d...

The electronic structure of DNA is determined by its nucleotide sequence, which is for instance exploited in molecular electronics. Here we demonstrate that also the DNA strand breakage induced by low-energy electrons (18 eV) depends on the nucleotide sequence. To determine the absolute cross sections for electron induced single strand breaks in specific 13 mer oligonucleotides we used atomic f...

Radiation treatment is popular and the apparatus is already available in many hospitals. Conventional radiation treatment by itself is not sufficient to achieve complete cure. Therefore, radiosensitizers have been developed to enhance the therapeutic effects of the treatment. The concept of radiosensitization with high-Z-elements was first considered many decades ago. However, radiosensitizers ...

2-(Thiophen-2-yl)thiazole was introduced as a π-bridge into diethylamino coumarin and novel coumarin sensitizers were synthesized with cyanoacrylic acid or rhodanine acetic acid as electron acceptor. Their light-harvesting capabilities and photovoltaic performance were investigated and compared with those of a similar sensitizer bearing a phenylthiophene bridge. Replacement of benzene in the π-...

Two therapeutic modalities are currently of great interest, namely photo- and radiosensitization. Whereas photosensitizers only function in combination with ultraviolet (UV) light, radiosensitizers act only in combination with ionizing radiation. Because of the small UV penetration, up to a maximum of 0,5 mm, photosensitization can take place only at the surface of the body, ie. the skin. Photo...

Sulfonamides and quinoxaline derivatives possess many types of biological activities and have been recently reported to show substantial antitumor activity. This paper reports the synthesis of novel thioureido sulfaquinoxaline derivatives. All the newly synthesized compounds were evaluated for their in vitro anticancer activity against a human liver cell line (HEPG2) and showed higher activity ...

-Bilateral kidney ligation of mice immediately before injection of misonidazole (MIS) prolongs the plasma half-life of this radiosensitizer from about 2 h (in normal mice) to 10-11 h, similar to that in man. Kidney ligation does not, however, change the relative proportions of MIS and its 0-demethylated metabolite, Ro-05-9963, for the first 12 h after MIS injection. Kidney ligation was used wit...

The effect of elevated temperature (44 degrees) on the intracellular uptake of the 2-nitroimidazole hypoxic cell radiosensitizer, misonidazole (MIS), and analogues more hydrophilic than MIS was studied in Chinese hamster ovary cells. It was found that the intracellular uptake of these compounds which enter cells by restricted passive diffusion can be enhanced approximately 4-fold when incubated...

Radiosensitizers can increase local treatment efficacy under a relatively low and safe radiation dose, thereby facilitating tumor eradication and minimizing side effects. Here, a new class of radiosensitizers is reported, which contain several gold (Au) atoms embedded inside a peptide shell (e.g., Au10-12 (SG)10-12 ) and can achieve ultrahigh tumor uptake (10.86 SUV at 24 h post injection) and ...