RESUMEN
This work describes the new facility for applied nuclear physics at the University of Sao Paulo, mainly for irradiation of electronic devices. It is a setup composed of a quadrupole doublet for beam focusing/defocusing plus multiple scattering through gold foils to produce low intensity, large-area, and high-uniformity heavy-ion beams from 1H to 107Ag. Beam intensities can be easily adjusted from 102 particles cm2/s to hundreds of nA for an area as large as 2.0 cm2 and uniformity better than 90%. Its irradiation chamber has a high-precision motorized stage, and the system is controlled by a LabViewTM environment, allowing measurement automation. Design considerations and examples of use are presented.
RESUMEN
Colorectal cancer is a global public health issue. Studies have pointed to the protective effect of probiotics on colorectal carcinogenesis. Activia® is a lacto probiotic product that is widely consumed all over the world and its beneficial properties are related, mainly, to the lineage of traditional yoghurt bacteria combined with a specific bacillus, DanRegularis, which gives the product a proven capacity to intestinal regulation in humans. The aim of this study was to evaluate the antigenotoxic, antimutagenic, and anticarcinogenic proprieties of the Activia product, in response to damage caused by 1,2-dimethylhydrazine (DMH) in Swiss mice. Activia does not have shown antigenotoxic activity. However, the percent of DNA damage reduction, evaluated by the antimutagenicity assay, ranged from 69.23 to 96.15% indicating effective chemopreventive action. Activia reduced up to 79.82% the induction of aberrant crypt foci by DMH. Facing the results, it is inferred that Activia facilitates the weight loss, prevents DNA damage and pre-cancerous lesions in the intestinal mucosa.
Asunto(s)
Focos de Criptas Aberrantes/prevención & control , Anticarcinógenos/farmacología , Neoplasias Colorrectales/prevención & control , Daño del ADN , Probióticos/farmacología , Yogur/microbiología , 1,2-Dimetilhidrazina , Focos de Criptas Aberrantes/inducido químicamente , Focos de Criptas Aberrantes/genética , Focos de Criptas Aberrantes/patología , Animales , Neoplasias Colorrectales/inducido químicamente , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Suplementos Dietéticos , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/patología , Masculino , RatonesRESUMEN
The incidence of colorectal cancer is growing worldwide. The characterization of compounds present in the human diet that can prevent the occurrence of colorectal tumors is vital. The oligosaccharide inulin is such a compound. The aim of this study was to evaluate the antigenotoxic, antimutagenic and anticarcinogenic effects of inulin in vivo. Our study is based on 3 assays that are widely used to evaluate chemoprevention (comet assay, micronucleus assay, and aberrant crypt focus assay) and tests 4 protocols of treatment with inulin (pre-treatment, simultaneous, post-treatment, and pre + continuous). Experiments were carried out in Swiss male mice of reproductive age. In order to induce DNA damage, we used the pro-carcinogenic agent 1,2-dimethylhydrazine. Inulin was administered orally at a concentration of 50 mg/kg body weight following the protocols mentioned above. Inulin was not administered to the control groups. Our data from the micronucleus assay reveal antimutagenic effects of inulin in all protocols. The percentage of inulin-induced damage reduction ranged from 47.25 to 141.75% across protocols. These data suggest that inulin could act through desmutagenic and bio-antimutagenic mechanisms. The anticarcinogenic activity (aberrant crypt focus assay) of inulin was observed in all protocols and the percentages of damage reduction ranged from 55.78 to 87.56% across protocols. Further tests, including human trials, will be necessary before this functional food can be proven to be effective in the prevention and treatment of colon cancer.
Asunto(s)
Focos de Criptas Aberrantes/prevención & control , Antineoplásicos/uso terapéutico , Inulina/uso terapéutico , Administración Oral , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacología , Quimioprevención , Neoplasias Colorrectales/prevención & control , Daño del ADN/efectos de los fármacos , Inulina/administración & dosificación , Inulina/farmacología , Masculino , Ratones , Micronúcleos con Defecto Cromosómico/efectos de los fármacosRESUMEN
Previous studies in rodents treated with the pro-carcinogen 1,2-dimethylhydrazine suggested that the consumption of wheat bran protected against DNA damage in the colon and rectum. Based on this information, we evaluated wheat bran as a functional food in the prevention and treatment of colon cancer. We used the aberrant crypt focus assay to evaluate the anticarcinogenic potential of wheat bran (Triticum aestivum variety CD-104), the comet assay to evaluate its antigenotoxicity potential, and the micronucleus assay to evaluate its antimutagenic potential. The wheat bran gave good antimutagenic and anticarcinogenic responses; the DNA damage decreased from 90.30 to 26.37% and from 63.35 to 28.73%, respectively. However, the wheat bran did not significantly reduce genotoxicity. Further tests will be necessary, including tests in human beings, before this functional food can be recommended as an adjunct in the prevention and treatment of colon cancer.