2 resultados para Arsenicals

em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast


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Most patients with acute myeloid leukaemia (AML) are older, with many unsuitable for conventional chemotherapy. Low-dose Ara-C (LDAC) is superior to best supportive care but is still inadequate. The combination of arsenic trioxide (ATO) and LDAC showed promise in an unrandomised study. We report a randomised trial of LDAC versus LDAC + ATO. Patients with AML according to WHO criteria or myelodysplastic syndrome with > 10% blasts, considered as unfit for conventional chemotherapy, were randomised between subcutaneous Ara-C (20mg b.d. for 10 days) and the same LDAC schedule with ATO (0.25 mg/kg) on days 1-5, 9 and 11, for at least four courses every 4 to 6 weeks. Overall 166 patients were entered; the trial was terminated on the advice of the DMC, as the projected benefit was not observed. Overall 14% of patients achieved complete remission (CR) and 7% CRi. Median survival was 5.5 months and 19 months for responders (CR: not reached; CRi: 14 months; non-responders: 4 months). There were no differences in response or survival between the arms. Grade 3/4 cardiac and liver toxicity, and supportive care requirements were greater in the ATO arm. This randomised comparison demonstrates that adding ATO to LDAC provides no benefit for older patients with AML. Leukemia (2011) 25, 1122-1127; doi:10.1038/leu.2011.59; published online 8 April 2011

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Rice is elevated in arsenic (As) compared to other staple grains. The Bangladeshi community living in the United Kingdom (UK) has a ca. 30-fold higher consumption of rice than white Caucasians. In order to assess the impact of this difference in rice consumption, urinary arsenicals of 49 volunteers in the UK (Bangladeshi n = 37; white Caucasians n = 12) were monitored along with dietary habits. Total urinary arsenic (As(t)) and speciation analysis for dimethylarsinic acid (DMA), monomethylarsonic acid (MA) and inorganic arsenic (iAs) was conducted. Although no significant difference was found for As(t) (median: Bangladeshis 28.4 µg L(-1)) and white Caucasians (20.6 µg L(-1)), the sum of medians of DMA, MA and iAs for the Bangladeshi group was found to be over 3-fold higher (17.9 µg L(-1)) than for the Caucasians (3.50 µg L(-1)). Urinary DMA was significantly higher (p <0.001) in the UK Bangladeshis (median: 16.9 µg DMA L(-1)) than in the white Caucasians (3.16 µg DMA L(-1)) as well as iAs (p <0.001) with a median of 0.630 µg iAs L(-1) for Bangladeshi and 0.250 µg iAs L(-1) for Caucasians. Cationic compounds were significantly lower in the Bangladeshis (2.93 µg L(-1)) than in Caucasians (14.9 µg L(-1)). The higher DMA and iAs levels in the Bangladeshis are mainly the result of higher rice consumption: arsenic is speciated in rice as both iAs and DMA, and iAs can be metabolized, through MA, to DMA by humans. This study shows that a higher dietary intake of DMA alters the DMA/MA ratio in urine. Consequently, DMA/MA ratio as an indication of methylation capacity in populations consuming large quantities of rice should be applied with caution since variation in the quantity and type of rice eaten may alter this ratio.