Aflatoxin B1 is a persistent public health issue in Ghana. Assessment of AFB1 intervention efficacy is currently dependent on long-term biomarkers. This study was designed to determine whether daily AFM1 biomarker levels could be utilized as an early detection method for intervention efficacy. Participants were treated with a refined calcium montmorillonite clay (UPSN) or a placebo (calcium carbonate) in a crossover study. Urine samples were assessed for AFM1 levels daily. UPSN treatment reduced AFM1 biomarkers by 55% compared to the placebo. This is the first study to show that daily urinary AFM1 levels can be used as a biomarker of internal aflatoxin B1 exposure in short-term intervention trials to determine efficacy.

SUMMARYBackground: Weanimix is an important food for children in Ghana. Mothers are trained to prepare homemade weanimix from beans, groundnuts and maize for their infants. Groundnuts and maize are prone to aflatoxin contamination while fumonisin contaminates maize. Aflatoxin, is produced by the Asperguillus fungi while fumonisin, is produced by Fusarium fungi. These mycotoxins occur in tropical areas worldwide due to favorable climate for their growth. Objective: The objective of the study was to determine the levels of aflatoxin and fumonisin in homemade weanimix in the Ejura-Sekyedumase district in the Ashanti Region of Ghana. Methods: Thirty six homemade weanimix samples (50g each) were collected from households. Aflatoxin and fumonisin were measured using a fluorometric procedure described by the Association of Official Analytical Chemist (AOAC official method 993.31, V1 series 4). Results: Aflatoxin and fumonisin were detected in all 36 samples, range 7.9-500ppb. Fumonisin levels range: 0.74-11.0ppm). Thirty (83.3%) of the thirty six samples were over the action limit of 20ppb for aflatoxin with an overall mean of 145.2 ppb whiles 58.3% of the samples had fumonisins above the action limit of 4 ppm with an overall mean of 4.7 ppm . Conclusion: There were significant aflatoxin and fumonisin contamination of homemade weanimix. Children fed on this nutritional food were being exposed to unacceptable levels of aflatoxin and fumonisin. Therefore there is a critical need to educate mothers on the dangers of mycotoxin exposure and to develop strategies to eliminate exposure of children fed homemade weanimix to aflatoxin and fumonisin.

This study is aimed at isolating colorectal cancer stem-like cells in vitro using a neurosphere assay method employed in isolating gliobastoma multiforme tumor cells. This was followed with confirmation of the isolated cells by flow cytometry, pluripotent genes expression and in vivo tumorigenicity assay. Using this culture assay, stem-like and non-stem-like CRC cells were isolated and expanded in vitro from purchased Balb/c mice induced with CT26 colorectal cancer (CRC) cell line. The procedure includes an initial mechanical dissociation and chemical digestion of tumor tissue and subsequently plating the resulting single cell suspension in serum-free medium (SFM) or serum-containing medium (SCM). This selectively permits growth of cancer stem-like cells in SFM and eliminates non-stem-like cancer cells through the process of anoikis or apoptosis. CRC stem cells derived cultures proliferated as non-adherent spheres in vitro in different shapes and sizes. These cells expressed cell surface markers previously reported for tumor stem cells, including CD44, CD133, CD166 and CD26 and formed tumors when implanted in severe combined immunodeficient mice in a concentration dependent manner. Importantly, the stem-like cells had self-renewal properties with significantly higher expression of the pluripotent stem cell genes NANOG, OCT4, and SOX2 compared to the adherent non-stem cells. Collectively, the results of this study indicate that SFM is a defined culture medium that enriches for CRC stem-like cells and represents a suitable in vitro model for the study of CRC stem-like cells. This finding may be useful in developing therapeutic strategies aimed at eradicating the tumorigenic subpopulation within colorectal cancer.