RESUMO
Since current microbiology methods are not suitable to detect Clostridium perfringens in formalin-fixed, paraffin-embedded tissue samples, we developed a PCR assay to detect toxin-encoding genes and the 16S rRNA gene of C. perfringens. We successfully detected and genotyped C. perfringens in tissue sections from two autopsy cases.
Assuntos
Toxinas Bacterianas/genética , Infecções por Clostridium/diagnóstico , Clostridium perfringens/genética , Reação em Cadeia da Polimerase/métodos , Preservação de Tecido/métodos , Toxinas Bacterianas/biossíntese , Clostridium perfringens/isolamento & purificação , DNA Bacteriano/genética , DNA Ribossômico/genética , Fixadores/farmacologia , Formaldeído/farmacologia , Genótipo , Humanos , Inclusão em Parafina , RNA Ribossômico 16S/genéticaRESUMO
Genistein, rich in soybean, has been reported to have anti-cancer activity on several cancers. However, the molecular mechanism of its anti-cancer activity still remains unclear. We investigated the effect of genistein on a human oral squamous carcinoma line (SCC-25), and demonstrated that genistein inhibited SCC-25 cell growth via G2/M phase arrest. We observed a significant decrease of proliferating cell nuclear antigen expression in these cells after treatment, but no significant change in the number of apoptotic cells, indicating that the major action of genistein is inhibition of cancer cell proliferation. We also observed a high level of prostaglandin E2 (PGE2) in these cells and PGE2 synthesis in SCC-25 cells was significantly suppressed by genistein. We demonstrated that genistein directly inhibited cycloxygenase-2 (COX-2) activity, an inducible enzyme that converts arachidonic acid to prostaglandins, similar to the action of celecoxib, a selective COX-2 inhibitor. However, the anticancer activity of genistein was much weaker than that of indomethacin (non-selective COX inhibitor), celecoxib and baicalein (flavonoid isolated from Scutellaria baicalensis). These results suggested that genistein might be useful as a chemopreventive agent rather than a chemotherapeutic agent.