The luminous intensity of dark variant (S1) separated from photobacterium phosphoreum (A2) was 1/10,000 less than that of wild-type. Ethidium bromide (EB) (0.6 mg/L), Mytomycin C (MC, 0.05 mg/L), 2-amino fluorene (2-AF, 1.0 mg/L) all could strongly induce reversion mutation for S1 within 24 h and increase reversion ratio significantly. The results of experiments indicated that these revertants had stable genetic characteristic and the mutation may take place at gene levels. The mutagenesis to S1 caused by EB, MC and 2-AF was detected and it may be used as a new rapid, simple and sensitive method for gene toxicant monitoring.
*Chemiluminescent Measurements ; Ethidium/pharmacology ; Ethidium/toxicity ; Luciferases/biosynthesis ; Mitomycins/pharmacology ; Mitomycins/toxicity ; Mutagens ; Mutation/*drug effects ; Photobacterium/*genetics ; Toxicology/methods ; Transcription, Genetic/drug effects ; Variation (Genetics)

The luminous intensity of dark variant (S1) separated from photobacterium phosphoreum (A2) was 1/10,000 less than that of wild-type. Ethidium bromide (EB) (0.6 mg/L), Mytomycin C (MC, 0.05 mg/L), 2-amino fluorene (2-AF, 1.0 mg/L) all could strongly induce reversion mutation for S1 within 24 h and increase reversion ratio significantly. The results of experiments indicated that these revertants had stable genetic characteristic and the mutation may take place at gene levels. The mutagenesis to S1 caused by EB, MC and 2-AF was detected and it may be used as a new rapid, simple and sensitive method for gene toxicant monitoring.
Ethidium ; pharmacology ; toxicity ; Genetic Variation ; Luciferases ; biosynthesis ; Luminescent Measurements ; Mitomycins ; pharmacology ; toxicity ; Mutagens ; Mutation ; drug effects ; Photobacterium ; genetics ; Toxicology ; methods ; Transcription, Genetic ; drug effects

OBJECTIVETo determine the in vitro possible clastogenic and cytotoxic activities of Ulva rigida crude extracts (URE), and identify their antigenotoxic and protective effects on chemotherapeutic agent mitomycine-C (MMC).

METHODSAnti-clastogenic and anti-genotoxic activities of Ulva rigida crude extracts (URE) were studied using chromosome aberration (CA), sister chromatid exchange (SCE), and micronuclei (MN) tests in human lymphocytes cultured in vitro.

RESULTSThe chromosome aberration, sister chromatid exchange or micronuclei tests showed that URE at concentrations of 10, 20, and 40 microg/mL had no clastogenic activity in human lymphocyte cell culture. Three doses of URE significantly decreased the number of chromosomal aberrations and the frequencies of SCE and MN when compared with the culture treated with MMC (P < 0.0001).

CONCLUSIONAlthough URE itself is not a clastogenic or cytotoxic substance, it possesses strong antigenotoxic, anti-clastogenic, and protective effects on MMC in vitro.

Antibiotics, Antineoplastic ; pharmacology ; Antimutagenic Agents ; pharmacology ; Cells, Cultured ; Chlorophyta ; Chromosome Aberrations ; drug effects ; Dose-Response Relationship, Drug ; Humans ; Lymphocytes ; drug effects ; metabolism ; Micronucleus Tests ; Mitomycins ; pharmacology ; Mutagens ; toxicity ; Plant Extracts ; chemistry ; pharmacology ; Sister Chromatid Exchange ; drug effects

OBJECTIVETo evaluate in vitro anti-tumor effect of chemotherapeutic drugs on human gastric cancer cells, and investigate the relationship with Bcl-2 expression.

METHODSSingle cell suspension was prepared from fresh gastric cancer tissue and exposed to taxol (Tax), 5-fluorouracil (5-FU), cisplatin (CDDP), adriamycin (ADM), mitomycin (MMC) respectively for 48 hours. Metabolic activity and inhibitory rate of cells were detected by MTT assay. Expression of Bcl-2 was examined with immunohistochemistry.

RESULTSThe inhibitory rates of cancer cells exposed to chemotherapeutic drugs were different and Tax, 5-FU, CDDP had remarkably higher rates than ADM and MMC. The lower differentiated gastric cancer cells were more sensitive than the higher ones. Positive expression rate of Bcl-2 was 80% and the positive cells showed resistance to 5-FU, ADM and MMC.

CONCLUSIONSChemosensitive testing by MTT assay can constitute the prediction for the application of chemotherapeutic drugs individually. Overexpression of Bcl-2 may contribute to multiple drug-resistance of tumors.

Adult ; Aged ; Antineoplastic Agents ; pharmacology ; therapeutic use ; Cell Survival ; Cisplatin ; pharmacology ; therapeutic use ; Doxorubicin ; pharmacology ; therapeutic use ; Drug Screening Assays, Antitumor ; Female ; Fluorouracil ; pharmacology ; therapeutic use ; Humans ; Male ; Middle Aged ; Mitomycin ; pharmacology ; therapeutic use ; Mitomycins ; pharmacology ; therapeutic use ; Paclitaxel ; pharmacology ; therapeutic use ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Stomach Neoplasms ; drug therapy ; metabolism ; pathology ; Tumor Cells, Cultured