The mutational response of mismatch repair-deficient animals to the alkylating agent N-methyl-N-nitrosourea was evaluated by using a transgenic lacI reporter system. Although the mutations detected in MSH2 heterozygotes were similar to those of controls, MSH2-/- animals demonstrated striking increases in mutation frequency in response to this agent. G:C to A:T transitions at GpG sites, as oppos...

Adult female rat urinary bladders were exposed to N-methyl-N-nitrosourea in vivo. After 12 weeks, urothelial hyperplasia was established. Ultrastructural changes of the luminal plasma membrane were studied with thin sectioning and freeze-fracturing techniques. The mosaic pattern which is a characteristic specialization of the normal luminal plasma membrane and of cytoplasmic vesicles disappeare...

The distribution of alkylated deoxynucleosides and bases has been determined in the DNA of a sensitive and a resistant human gliomaderived cell line exposed to therapeutic levels of |'"l1|.Y-(2-chloroethyl)/V-nitrosourea in vitro. The resistant cell line is 5-fold less sensitive to the cytotoxic effects of yV-(2-chloroethyl)-Ar-nitrosourea and 8-fold less sensitive to sister chromatid exchange ...

The continuous human medulloblastoma cell line TE-671 was grown as s.c. and intracranial xenografts in athymic nude mice. Tumor-bearing animals were treated with chemotherapeutic agents at the 10% lethal dose; s.c. xenografts were sensitive to melphalan, 1-(2-chloroethyl)-3-(2,6-dioxo-1-piperidyl)-1-nitrosourea, and 5-azacytidine. No consistent response could be demonstrated to 9-beta-D-arabino...

Long-term survivors of mice bearing a transplanted leukemia have been obtained following treatment with a combination of amphotericin B and 1, 3-bis(2-chloroethyl)1-nitrosourea. The proportion of mice surviving at 28 days depended upon the order and timing of drug adminis tration. Optimal results were obtained when 0.5 mg am photericin B was given 24 hr before 0.2 mg l, 3-bis(2-chloroethyl)-l-n...

The sensitivity of human and murine cate that human and murine hemopoietic hemopoietic precursor cells to 1 ,3 bis cells may differ in their intrinsic sensitivity (2 chloroethyl)-1-nitrosourea (BCNU), nitodrugs. The hematologic toxicity of some trogen mustard, 5-fluorouracil, and melchemotherapeutic agents cannot be cxphalan was assessed in culture using trapolated directly from mouse to man. c...

3-Triflyloxybenzyne was generated via an iodine-magnesium exchange reaction of 1,3-bis(triflyloxy)-2-iodobenzene using the trimethylsilylmethyl Grignard reagent. Various arynophiles and nucleophiles reacted regioselectively with 3-triflyoxybenzyne to afford cycloadducts and unique aryl triflones, which were provided via thia-Fries rearrangement.

stinging nettle (urtica dioica l.,) is a medicinal herb commonly used by humans. the role of reactive oxygen metabolites on cancer etiology is known. there are some studies about the antioxidant effects of urtica dioica (ud) on therapy of some cancer types. this study aimed to investigate the effects of ud on antioxidant enzyme activities and mammary gland cancer induced by in rats-n-methyl-n-n...