PROMEC Unit, Medical Research Council, Tygerberg 7505, South Africa.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2008 Nov;25(11):1385-91. doi: 10.1080/02652030802226195.
High incidences of oesophageal cancer are associated with the consumption of subsistence-grown maize by rural populations in the former Transkei region of Eastern Cape Province, South Africa. This cross-sectional study was conducted in the north-eastern magisterial area of Bizana (a previously low oesophageal cancer incidence area) and the south-eastern area of Centane (a previously high incidence area). Plasma and urine samples of male and female participants were analysed for the sphingoid bases, sphinganine and sphingosine. Good home-grown and visibly mouldy maize samples, collected from the households of the participants, were analysed for fumonisin B(1), B(2) and B(3). Plasma sphinganine/sphingosine ratios in males and females were significantly lower (p < 0.05) due to lower sphinganine levels in Bizana compared to Centane. In contrast, the urinary female and combined (males + females) sphinganine/sphingosine ratios were significantly higher (p < 0.05) in Bizana due to the significantly lower (p < 0.05) urinary sphingosine levels. Interestingly, urinary sphingoid base levels were significantly lower (p < 0.05) in males than females within each area. Based on the mean total fumonisin levels in good maize, the estimated mean probable daily intake (PDI) was 5.8 microg kg(-1) body weight day(-1) in Bizana during 2000 and 4.4 and 6.7 5.8 microg kg(-1) body weight day(-1) in Centane during 1997 and 2000, respectively, exceeding the maximum tolerable daily intake proposed by JECFA. However, there was no significant difference in the mean total fumonisin levels in the maize between the magisterial areas. The observed differences in plasma and urinary sphingoid base levels could not be ascribed as a biomarker of fumonisin exposure and further studies at an individual level are required.
高发生率的食管癌与南非东开普省前特兰斯凯地区农村人群消耗自给种植的玉米有关。本横断面研究在Bizana 东北自治区（以前是食管癌低发区）和 Centane 东南地区（以前是高发区）进行。分析了男性和女性参与者的血浆和尿液样本中的神经鞘氨醇碱基、神经鞘氨醇和神经氨酸。从参与者家中采集了良好的自制和明显发霉的玉米样本，分析了伏马菌素 B(1)、B(2) 和 B(3)。与 Centane 相比，Bizana 男性和女性的血浆神经氨酸/神经鞘氨醇比值显著降低（p < 0.05），这是由于神经氨酸水平降低所致。相反，由于尿中神经氨酸水平显著降低（p < 0.05），Bizana 女性和（男性+女性）混合尿神经氨酸/神经鞘氨醇比值显著升高。有趣的是，每个地区内男性尿神经鞘氨醇碱基水平均显著低于女性。基于良好玉米中总伏马菌素的平均值，估计 2000 年 Bizana 的每日平均可能摄入量（PDI）为 5.8μgkg(-1)体重日(-1)，1997 年和 2000 年 Centane 分别为 4.4 和 6.7μgkg(-1)体重日(-1)，超过了 JECFA 提出的最大耐受日摄入量。然而，两个自治区玉米中总伏马菌素的平均水平没有显著差异。血浆和尿液中神经鞘氨醇碱基水平的观察差异不能归因于伏马菌素暴露的生物标志物，需要在个体水平上进行进一步研究。
