Immature corn as a source of niacin for rats

The variability in the concentration and biological availability of niacin in corn was investigated. Plots of both sweet and field corn were harvested at different stages. In rat growth assays for available niacin, grains harvested at the immature, "milky" stage and then dried gave values of 88 and 74 micrograms/g, respectively. These values were in contrast to the low growth assay values of 18 and 16 micrograms/g for grain harvested at maturity, and even higher than the value of approximately 56 micrograms/g obtained for each immature corn in both the Association of Official Analytical Chemists procedure of chemical analysis and a standard microbiological procedure. However, when the milky grains were precooked at neutral pH, the values from these procedures were higher and agreed with the biological assay results. It is suggested that, during the initial alkaline digestion used for these two procedures, a proportion of the niacin in NAD, the major form of niacin in milky corn, degrades. However, when the materials are first cooked at neutral pH, nicotinamide is released without loss, and the pyridine ring is then stable. The traditional American Indian practice of roasting and drying "green corn" apparently provided a valuable source of niacin.     

安徽省主粮中杂色曲霉素污染状况调查

报道了安徽省部分地区小麦、玉米、大米三种主要粮食中霉菌侵染状况。杂色曲霉素（ＳＴ）用化学方法提取，毒素含量测定用灵敏、快速的ＥＬＬＳＡ方法。结果表明三种粮食中霉菌侵染严重，侵染率分别为９６．２７％，８４．７９％和２６．８０％。霉菌菌相以曲霉为主。ＳＴ在粮食中污染较普遍，阳性率为６７．２％～１００％，平均含量为０．４９～２３１．５３μｇ／ｋｇ。尤其在小麦中阳性率高达１００％，平均含量达１６１．３μｇ／ｋｇ，１９９４年收获的小麦、玉米平均含毒量明显高于１９９５年收获的小麦、玉米，说明ＳＴ在粮食储藏过程中易产生     

The Economics of Atrazine

Abstract

It is often claimed that atrazine is of great economic benefit to corn growers, but support for this claim is limited. Some cost-benefit studies have assumed that atrazine boosts corn yields by 6%; an extensive review found a 3%–4% average yield increase; other research suggests only a 1% yield effect. Syngenta, the producer of atrazine, also makes mesotrione, an alternative herbicide that does about the same amount for corn yields as atrazine. Italy and Germany both banned atrazine in 1991, with no decrease in corn Yields or harvested area. Even if atrazine leads to 6% more corn production, it is not certain that this would justify its continued use; a 1%, or perhaps zero, change does not warrant largescale exposure of humans and the environment to this potentially hazardous chemical.     

The economics of atrazine

It is often claimed that atrazine is of great economic benefit to corn growers, but support for this claim is limited. Some cost-benefit studies have assumed that atrazine boosts corn yields by 6%; an extensive review found a 3%-4% average yield increase; other research suggests only a 1% yield effect. Syngenta, the producer of atrazine, also makes mesotrione, an alternative herbicide that does about the same amount for corn yields as atrazine. Italy and Germany both banned atrazine in 1991, with no decrease in corn yields or harvested area. Even if atrazine leads to 6% more corn production, it is not certain that this would justify its continued use; a 1%, or perhaps zero, change does not warrant large-scale exposure of humans and the environment to this potentially hazardous chemical.     

Exposure of field workers to organophosphorus insecticides: Sweet corn and peaches

Plasma and red blood cell cholinesterase levels of professional agricultural workers engaged in packing sweet corn and thinning peaches were monitored. Workers with extensive contact with mechanically harvested sweet corn (the corn had been treated one or two days before harvest with a combination of ethyl and methyl parathion) exhibited significant depression of cholinesterase. Gloves, worn by 40% of the workers, provided some protection from absorption of pesticide residues. No significant cholinesterase depression was found in workers thinning peaches which had been previously treated with parathion.     

ULCERS IN SWINE

Ulcers have been seen in as many as 55 per cent of the swine fed a commercial pelleted ration or one containing heated corn; in the latter study, no ulcers were seen among the animals fed the ration containing unhealed corn.     

镇雄县部分地区燃煤拌煤黏土对食物中氟含量的影响

目的探讨云南省镇雄县氟中毒区食物中氟含量、分布情况以及燃煤、拌煤黏土烘烤玉米、辣椒对其氟含量的影响,为制定相应防护措施提供科学依据。方法取镇雄县乌峰镇、塘房镇、以勒镇新鲜玉米、辣椒,改造火炉烘烤后的玉米、辣椒各15份,共240份。采用酸浸/电极法测定氟含量、用SPSS 18.0统计软件经配对t检验处理数据。P0.05为差异有统计学意义。结果同新鲜玉米、辣椒比较,烘烤1周及烘烤4个月的玉米、辣椒氟含量明显增高(P均0.01),烘烤4个月的玉米氟含量显著高于烘烤1周的玉米氟含量[塘房:(14.13±3.54)mg/kgvs(5.38±0.75)mg/kg,P0.01;以勒:(26.46±21.62)mg/kgvs(12.85±1.81)mg/kg,P0.05]。结论玉米、辣椒用燃煤、拌煤黏土烘烤后氟含量显著增高,烘烤时间越长,氟含量越高。     

THE DIET AND LIPID METABOLISM IN MAN

A low fat diet may cause hypertriglyceridemia. This result can be avoided by providing at least 10 per cent and preferably more of calories as corn oil. Heated corn oil did not produce toxic effects.     

两种玉米主食膳的人体表观消化率

<正> 在玉米仍占居民口粮比重较大的地区,一些主食制售与科研单位,正在研究玉米主食的加工制做方式。这种制品的营养价值,不能不引起人们的注意。包括玉米在内的粮食的营养价值,取决于其营养成分组成、在人体内的消化率和某些营养素的利用率。但就作为主食的制做方式而言,对其中营养素组成和利用率影响不大,因而此类工作的许多文献报告,均以其主要营养素的人体表观消化率为评价标志。     

SEASONAL HUNGER IN UNDERDEVELOPED COUNTRIES

The nutritional condition among the rural adults of northern Ghana is characterized by a gain in body weight as soon as the crops have been harvested followed by a loss of weight as food supplies diminish during the long dry season.     

NITROGEN RETENTION IN MAN IN RELATION TO THE LEVEL AND PATTERN OF ESSENTIAL AMINO ACIDS

At a constant nitrogen intake, increasing the intake of essential amino acids increased nitrogen retention in young adult men. This effect occurred when the EAA were supplied in the pattern of corn protein, as well as of egg protein.     

ACCUMULATION OF 5-METHYLTETRAHYDROFOLIC ACID IN ETHANOL-TREATED HEPATOCYTES

Ethanol metabolism is associated with enhanced influx of 5-methyltetrahydrofolic acid into isolated hepatocytes. This may be due to an increased NADH:NAD ratio.     

ALKALINE HYDROGEN PEROXIDE UNLOCKS ENERGY IN HIGH-FIBER LIGNIFIED BY-PRODUCTS

Treatment of wheat straw, corn cobs, and corn stalks with alkaline H₂O₂ doubles the utilization of fiber by ruminant animals.     

DIET INDUCED CIRRHOSIS AND LINOLEIC ACID IN THE RAT

Rats fed diets producing cirrhosis show a higher incidence of fibrosis when the diet is high in corn oil than when hydrogenated corn oil is substituted.     

CLOT-STRENGTH AND CLOT-LYSIS IN RATS FED HYPERLIPEMIC DIETS

Rats fed hypercholesterolemia diets containing large amounts of butter or corn oil show marked changes in several characteristics related to coagulation. However, with at least one characteristic the effect of the butter containing diet was more severe than that of the corn oil containing diet.     

ATHEROGENESIS IN THE MONKEY

Histological and chemical analysis was performed on tissue samples surgically removed from Cebus monkeys before, during, and after the feeding of diets containing corn oil, butterfat or coconut oil supplements.     

ABSORPTION OF IRON IN RATS

Absorption of iron in anemic rats depends upon the form of iron fed and the constituents of the diet. Inorganic iron absorption was increased substantially in diets containing lactose compared with those in which the carbohydrate was starch. Comparisons of the absorption of iron from corn and meat raise questions as to whether the rat is a suitable model for the estimation of availability of food iron for man.     

Elevation of blood NAD level after moderate exercise in young women and mice

We previously reported that the blood NAD levels are decreased by severe exercise, and administration of nicotinamide, a precursor of NAD, improves the endurance capacity of mice. In the present study, we determined whether moderate exercise changes the blood NAD levels in humans and mice. College female students exercised moderately with bike-ergometers. The blood NAD levels elevated after moderate exercise. Mice were forced to swim in a running water pool for 5 min as a moderate exercise, 15 min as a strong exercise, and until exhaustion as a severe exercise (average swimming time was 28.7 min). A 5 min swim gave a result similar to that of moderate exercise by human subjects. However, the blood NAD levels decreased after all-out exercise. The changes in whole blood tryptophan (a precursor of pyridine nucleotides) levels were similar to that in NAD. The glucose levels in whole blood and the non-esterified fatty acid levels in serum decreased according to exercising time. These data are the first demonstration of moderate exercise raising the blood NAD levels in human and mice. Elevation of the blood NAD levels may reflect changes in niacin metabolism that occur in response to exercise.     

2007-2008年中国谷物中隐蔽型脱氧雪腐镰刀菌烯醇及多组分真菌毒素污染状况

目的 了解我国部分地区谷物中隐蔽型脱氧雪腐镰刀菌烯醇(DON-3-G)及多组分真菌毒素污染状况.方法 2007-2008年在河南、河北、广西、安徽、四川、重庆和江苏7个省(市、自治区)采集玉米、小麦等样品共计446份,用超高效液相色谱-串联质谱(UPLC-MS/MS)方法检测样品中DON-3-G及多组分真菌毒素[包括脱氧雪腐镰刀菌烯醇(DON)、玉米赤霉烯酮(ZEN)、雪腐镰刀菌烯醇(NIV)等]的污染状况.结果 小麦、玉米中污染的主要真菌毒素为DON及其衍生物和ZEN.88%(169/192)的小麦样品中检出DON(1.5～590.7μg/kg;中位数:30.8μg/kg);22.9%(44/192)的小麦样品中ZEN阳性(1.7～3425.0 μg/kg;中位数:8.0μg/kg),其中有6份样品中ZEN含量超过我国规定的限量标准(60μg/kg).50.5%(103/204)的玉米样品中DON阳性(1.6～4374.4 μg/kg;中位数:94.9μg/kg),7份样品中DON含量超过我国规定的限量标准(1000μg/kg);41.7%(85/204)的玉米样品中ZEN阳性(1.6～4808.7 μg/kg;中位数:48.5μg/kg),其中有37份超过我国规定的限量标准(60 μg/kg).首次在国产小麦和玉米中检出DON-3-G,小麦、玉米样品中DON-3-G中位数分别为21.4μg/kg和34.6 μg/kg,小麦中DON-3-G均高于3-乙酰化DON(3-A-DON,中位数:4.1μg/kg)和15-乙酰化DON(15-A-DON,中位数:3.1μg/kg)(t值分别为5.111和5.966,P值均<0.01);玉米中15-A-DON(中位数:48.6μg/kg)高于3-A-DON(中位数:6.8 μg/kg)(t=-3.579,P<0.01).玉米中DON、DON-3-G、3-A-DON、15-A-DON和ZEN的污染水平均高于小麦(Z值分别为-3.492、-1.960、-2.467、-8.711和-6.272,P值均<0.05),而NIV在小麦中水平(中位数:29.0μg/kg)高于玉米(中位数:18.2μg/kg)(Z=-2.086,P<0.05).结论 我国部分地区小麦、玉米被多组分真菌毒素污染,以DON检出率最高;玉米中受DON、DON-3-G、3-A-DON、15-A-DON和ZEN的污染比小麦重.

Abstract：

Objective To elucidate the natural occurrence of masked deoxynivalenol (DON-3-G)and other multi-mycotoxins in cereals from parts of China. Methods A total of 446 corn and wheat samples harvested in 2007 and 2008 collected from Henan, Hebei, Guangxi, Anhui, Sichuan, Chongqing and Jiangsu provinces were analyzed for DON-3-G and other multi-mycotoxins (including deoxynivalenol (DON),zearalenone(ZEN), nivalenol (NIV), et al) by UPLC-MS/MS. Results Corn and wheat samples were mainly contaminated by DON and its derivatives as well as ZEN. 88% (169/192) of wheat samples were positive for DON (range: 1.5-590. 7 μg/kg; median: 30. 8 μg/kg) ;22. 9% (44/192) of wheat samples were contaminated with ZEN (range: 1. 7-3425.0 μg/kg; median: 8.0 μg/kg) and six samples contained ZEN concentration higher than the ZEN tolerance limit of 60 μg/kg. DON was detected in 50. 5% (103/204) corn samples (range: 1.6-4374. 4 μg/kg; median: 94. 9 μg/kg); Seven samples contained DON exceeding the tolerance limit of 1000 μg/kg for DON. Additionally, ZEN was found in 41.7% (85/204) corn samples with the concentration between 1.6 μg/kg and 4808.7 μg/kg (median:48.5 μg/kg)and there were 37 corn samples with ZEN level in the excess of tolerance limit for ZEN (60 μg/kg). DON-3-G was detected in corn and wheat samples for the first time in China with the median level of 21.4 μg/kg and 34. 6 μg/kg for wheat and corn,respectively. Wheat was more heavily contaminated with DON-3-G than both 3-aeetly-DON (3-A-DON,median:4. 1μg/kg) and 15-acetly-DON (15-A-DON,median :3. 1 μg/kg)(t values were 5. 111 and 5. 966, respectively,both P values <0. 01). While,the level of 15-A-DON (median: 48. 6 μg/kg) in corn was higher than 3-A-DON (median: 6. 8 μg/kg) (t =-3. 579,P < 0. 01). The concentration of DON, DON-3-G, 3-A-DON, 15-A-DON and ZEN in corn were higher than that in wheat (Z values were-3. 492,-1. 960,-2. 467,-8. 711 and-6. 272, respectively,all P values < 0. 05). Wheat(median: 29. 0 μ.g/kg) contained higher NIV in comparison with corn(median:18.2 μg/kg,Z=-2.086,P<0.05). Conclusion Wheat and corn samples from parts of China were contaminated with multi-mycotoxins and DON was the predominant;in comparison of wheat,corn was more heavily contaminated with DON, DON-3-G,3-A-DON, 15-A-DON and ZEN.     

NADase细菌毒素的活性测定

旨在建立一种测定ＮＡＤａｓｅ细菌毒素活性的非放射性测定法。本方法建立了一个ＮＡＤ（辅酶Ⅰ）依赖的显色系统，在该系统中，ＮＡＤ接受乳酸脱氢酶（ＬＤＨ）从乳酸脱下来的氢，再通过ＰＭＳ（吩嗪二甲酯硫酸盐）传递给ＩＮＴ（碘化硝基四氮唑蓝），使后者还原而显色。如果ＮＡＤａｓｅ毒素分解ＮＡＤ，就会打断递氢链而抑制显色反应。结果：显色系统中，ＮＡＤ含量与显色有良好线性关系（Ｒ＝０．９８９８）。绿脓杆菌外毒素Ａ分解ＮＡＤ而抑制显色反应。以毒素含量为自变量，以毒素对显色反应的抑制为应变量，建立了对数线性回归方程ｙ＝１２．５ｘ０．２６当ｙ＝５０％时［即显色系统中的ＮＡＤ有半数（２５０ｎｇ）被分解］，ｘ＝２０７（ｎｇ）。定义分解１ｎｇＮＡＤ的毒素活性为一个单位，则２０７ｎｇ毒素含有２５０个毒素活性单位。该方法的测定敏感性达到“ｎｇ”水平，表明本文建立的方法是一种敏感的测定ＮＡＤａｓｅ细菌毒素活性的非放射性测定方法