Tissue residues and urinary excretion of zilpaterol in sheep treated for 10 days with dietary zilpaterol

Zilpaterol is a beta-adrenergic growth promoter approved in Mexico and South Africa for use in cattle. Understanding the rates of zilpaterol depletion from tissues and urine is of interest for the development of strategies to detect the off-label use of zilpaterol. Eight sheep were fed 0.15 mg/kg/day dietary zilpaterol hydrochloride (Zilmax) for 10 consecutive days; two sheep each were slaughtered 0, 2, 5, and 9 days after discontinuation of exposure to the zilpaterol-containing diet. Tissue zilpaterol levels rapidly decreased during the withdrawal period. On the basis of LC-MS/MS-ES (external standard) measurements, liver zilpaterol residues in sheep were 29.3, 1.5, 0.13, and 0.10 ng/g after 0, 2, 5, and 9 day withdrawal periods, respectively; kidney residues were 29.6, 1.10, and 0.09 ng/g and below the detection limit; and muscle residues were 13.3, 0.86, 0.12, and 0.08 ng/g at the same respective withdrawal periods. Between-animal variation in urinary zilpaterol concentrations during the feeding period was considerable, although zilpaterol concentrations converged somewhat as steady state was reached. During the first 3 days of the withdrawal period, zilpaterol elimination followed a first-order excretion pattern, having an average elimination half-life of 15.3 +/- 1.8 h. Urinary zilpaterol concentrations during the withdrawal period were determined using ELISA, HPLC-fluorescence, LC-MS/MS-ES (external standard), and LC-MS/MS-IS (internal standard). Comparison of these methods showed a high correlation with each other. With the exception of LC-MS/MS-IS, the regression coefficients of the linear equations with a zero intercept were between 0.90 and 1.25, indicating the near equivalence of the methods. Because of its simplicity, ELISA is a convenient assay for determining zilpaterol levels in urine giving similar results to HPLC-fluorescence and LC-MS/MS-ES without requiring the extensive cleanup of the latter methods.     

Monetary costs of dietary energy reported by young Japanese women: association with food and nutrient intake and body mass index

OBJECTIVE: Little is known about the relationship of monetary diet costs to dietary intake and obesity, particularly in non-Western populations. This study examined monetary cost of dietary energy in relation to diet quality and body mass index (BMI) among young Japanese women. DESIGN: Dietary intake was assessed by a validated, self-administered, diet history questionnaire. Diet costs were estimated using retail food prices. Monetary cost of dietary energy (Japanese yen 1000 kcal-1) was then calculated. BMI was computed from self-reported body weight and height. SUBJECTS: A total of 3931 female Japanese dietetic students aged 18-20 years. RESULTS: Monetary cost of dietary energy was positively associated with intakes of fruits, vegetables, fish and shellfish, and pulses; however, higher monetary cost of dietary energy was also associated with higher consumption of fat and oil, meat and energy-containing beverages, and lower consumption of cereals (rice, bread and noodles) (all P for trend <0.01). At the nutrient level, monetary cost of dietary energy was positively associated with intakes of dietary fibre and key vitamins and minerals, but also associated positively with intakes of fat, saturated fatty acids, cholesterol and sodium, and negatively with carbohydrate intake (all P for trend <0.0001). After adjustment for possible confounders, monetary cost of dietary energy was quite weakly but significantly negatively associated with BMI (P for trend = 0.0197). CONCLUSIONS: Increasing monetary cost of dietary energy was associated with both favourable and unfavourable dietary intake patterns and a quite small decrease in BMI in young Japanese women.     

Consumption of wonderful variety pomegranate juice and extract by diabetic patients increases paraoxonase 1 association with high-density lipoprotein and stimulates its catalytic activities

Association of paraoxonase 1 (PON1) with high-density lipoprotein (HDL) stabilizes the enzyme. In diabetic patients, PON1 dissociates from HDL and, as a consequence, is less biologically active. Our aim was to investigate the effects of Wonderful variety pomegranate juice (WPJ) and pomegranate polyphenol extract (WPOMxl) consumption on PON1 association with HDL in diabetic patients. Thirty patients with type 2 diabetes mellitus participated in the study. Ten male patients and 10 female patients received concentrated WPJ (50 mL/day for 4 weeks), while another group of 10 male patients received WPOMxl (5 mL/day for 6 weeks). There were no significant effects of WPJ or WPOMxl consumption on fasting blood glucose or hemoglobin A1c levels. After 4 weeks of WPJ consumption by male patients, basal serum oxidative stress was significantly decreased by 35%, whereas serum concentrations of thiol groups significantly increased by 25%. Moreover, HDL-associated PON1 arylesterase, paraoxonase, and lactonase activities increased significantly after WPJ consumption by 34-45%, as compared to the baseline levels. PON1 protein binding to HDL was significantly increased by 30% following WPJ consumption, and the enzyme became more stable. In male patients that consumed WPOMxl and in female patients that consumed PJ, a similar pattern was observed, although to a lesser extent. We conclude that WPJ as well as WPOMxl consumption by diabetic patients does not worsen their diabetic parameters. Furthermore, WPJ as well as WPOMxl consumption contribute to PON1 stabilization, increased association with HDL, and enhanced catalytic activities. These beneficial effects of pomegranate consumption on serum PON1 stability and activity could lead to retardation of atherosclerosis development in diabetic patients.     

Consumption of juice fortified with oregano extract markedly increases excretion of phenolic acids but lacks short- and long-term effects on lipid peroxidation in healthy nonsmoking men

Oregano has been shown to possess antioxidant capacity in various in vitro models and has thus been suggested to be potentially beneficial to human health, but studies in humans are lacking. The aim of this study was to investigate the bioavailability and the effects of Origanum vulgare extract supplementation on serum lipids and lipid peroxidation in healthy nonsmoking men. A four-week double-blinded supplementation trial was concluded in which volunteers (n = 45) were randomized to consume daily mango-orange juice (placebo), mango-orange juice enriched with 300 mg/d total phenolic compounds from oregano extract, or mango-orange juice enriched with 600 mg/d total phenolic compounds from oregano extract. The excretion of phenolic compounds was markedly increased in the higher phenolic group as compared to the placebo group, but no significant changes were observed in the safety parameters, serum lipids, or biomarkers of lipid peroxidation.     

Hydrophobicity of whey protein concentrates measured by fluorescence quenching and its relation with surface functional properties

Surface hydrophobicity of whey protein concentrate (WPC) under heated (85 degrees C for 5, 10, 20, 30, 40, and 60 min) and unheated conditions was measured using cis-parinaric acid (CPA), 1-anilino-8-naphthalenesulfonate (ANS), and a fluorescence quenching method using acrylamide as a quencher. This last method evaluates the degree of exposure of tryptophanyl residues in proteins to the solvent. The initial slope of Stern-Volmer plots, K(app), was used as an index of protein hydrophobicity. Surface hydrophobicity of WPC exhibited good relation with surface functional properties such as emulsifying and foaming. Analysis of the data obtained in this work showed that the fluorescence quenching method gave results similar to those obtained using CPA and ANS. Therefore, this simple technique is satisfactory in effectively obtaining information about the hydrophobicity of whey proteins.     

不同钠吸附比的咸水结冰融水入渗后滨海盐土的水盐分布

在室内利用相同矿化度(10 g·L^-1)、不同钠吸附比(5、10 和30)的咸水进行咸水结冰融水模拟试验、结冰融水入渗和咸水直接入渗的土柱试验, 以淡水处理为对照, 分析不同钠吸附比咸水结冰融水入渗下滨海盐土水盐分布特征。结果表明: 咸水冰融化过程中, 融出水的矿化度和钠吸附比均呈由高到低的变化趋势。咸水结冰融水入渗速度和入渗深度均快于和深于淡水。咸水钠吸附比越小, 结冰融水入渗速率越快、深度越深。水盐分布也表现为低钠吸附比咸水结冰处理的表层土壤含水量较低, 水分向深层迁移, 这种水分分布也使盐分向深层运移, 表现为表层土壤含盐量低, 深层土壤含盐量大。土层含水量低钠吸附比咸水处理高于高钠吸附比处理, 10~45 cm 土层则表现出相反的趋势; 表层土含盐量低钠吸附比处理高于高钠吸附比处理, 且咸水处理下土壤脱盐的深度大于淡水处理。钠吸附比5 的咸水结冰处理, 0~10 cm 土壤平均含水量和含盐量分别为30.3%和1.1 g·kg^-1, 显著低于其他处理。为比较咸水结冰灌溉和咸水直接灌溉的效果, 室内利用含盐量为10 g·L^-1、钠吸附比10 的咸水进行直接入渗的土柱(土壤含盐量为21.3 g·kg^-1)模拟试验, 结果表明: 与咸水直接入渗处理相比, 咸水结冰融水处理盐分淋洗效果更好, 该处理0~25 cm土层平均土壤含盐量为2.9 g·kg^-1, 显著低于咸水直接入渗的10.6 g·kg^-1。     

Associations of television viewing time with excess body weight among urban and rural high-school students in regional mainland China

OBJECTIVE: To examine the relationship between television (TV) viewing and body mass index (BMI) among adolescents in a region of mainland China. DESIGN: Population-based cross-sectional study, conducted between September and November of 2004, on a sample of enrolled high-school students aged 12-18 years. SETTING: One hundred and sixty-eight classes randomly selected from both urban and rural areas and belonging to 15 senior and 41 junior high schools in Nanjing, China, with a regional population of 6.0 million. SUBJECTS: In total 6848 students participated; 47.7 % from urban and 52.3 % from rural areas; 49.0 % male and 51.0 % female. The response rate among eligible participants was 89.3 %. RESULTS: The proportion of overweight was 6.6 % according to the criteria of overweight recommended for Chinese adolescents. Boys than girls (8.9 % vs. 4.4 %) had higher odds of being overweight (odds ratio (OR) 2.12, 95 % confidence interval (CI) 1.74, 2.60), while the proportion of overweight was significantly lower among rural students than urban students (4.5 % vs. 8.9 %; OR 0.49, 95 % CI 0.40, 0.60). Those students who watched TV for more than 7 h/week had a 1.5 times greater odds of being overweight relative to their counterparts who watched TV for 7 h/week or less (adjusted OR 1.51, 95 % CI 1.24, 1.82). Furthermore, there was a positive linear relationship between TV viewing time and BMI, even after adjusting for age, gender, residence area, time spent in study, in sleeping and in physical activity, and monthly pocket money. CONCLUSIONS: Viewing TV might increase the likelihood of being overweight for Chinese adolescents in China.     

不同母质发育水稻土N2O消耗潜力及环境影响因素

土壤是N2O的源和汇,在淹水和厌氧条件下具有消耗N2O的能力。稻田土壤长期处于淹水状态,为N2O的消耗提供了有利的环境,从而减少了N2O排放。目前,有关稻田土壤N2O排放的相关研究已有很多,但关于稻田表层土壤N2O的消耗能力及其与环境因素之间的关系研究较少。研究采集了第四纪红壤母质发育的壤土、湖积物砂土发育的砂质壤土、冲积土发育的粉砂质黏壤土3类土壤的各3个表层(0～5 cm)水稻土,风干后将其回填至具有5 cm深土柱的培养装置内,在土柱底部添加N2O和添加氦气(He,对照)两个处理,于28℃下恒温淹水厌氧培养96 h。培养期间监测各土壤N2O、N2的动态变化,以及培养前后土壤养分的变化,量化N2O消耗量和N2增量,以期揭示稻田表层土壤N2O的消耗能力及其与环境因素之间的关系。结果表明,土壤剖面积累的N2O有95.01%～99.92% 被稻田表层土壤吸收,其中被还原为N2的N2O量占总消耗量的64.50%～83.64%,表明淹水厌氧状态下,不同的水稻土均具有很强的N2O吸收和消耗能力。研究还发现,3类土壤N2O的消耗存在一定差异,其中影响砂质壤土N2O消耗的主要环境因子为土壤砂粒含量,且两者之间存在显著的线性相关关系(R2=0.964,P=0.000);土壤黏粒、粉砂粒、pH是粉砂质黏壤土N2O消耗的主要环境影响因素,其中土壤黏粒与其消耗量呈显著线性相关(P<0.05);土壤速效钾和铵态氮增加量是影响壤土N2O消耗的主要环境因子,其消耗量与速效钾之间在0.01水平上显著正相关。这些结果表明,土壤可溶性有机碳、土壤质地、土壤速效钾等是影响稻田土壤N2O消耗的重要环境因子,且不同土壤N2O消耗的环境影响因子存在差异,这将为调节土壤N2O排放提供重要参考。     

Cholesterol oxidation in meat products and its regulation by supplementation of sodium nitrite and apple polyphenol before processing

The levels of cholesterol oxidation derivatives (OxChol) in eight commercial species of meat products were examined. These products contained more than 1 mg/100 g of OxChol, and 7beta-hydroxycholesterol + 5beta-epoxycholesterol (111-1092 microg/100 g), 5alpha-epoxycholesterol (80-712 microg/100 g), cholestanetriol (0-368 microg/100 g), and 7-ketocholesterol (708-1204 microg/100 g) were detected. To know the interaction of sodium nitrite supplementation against cholesterol oxidation in meat products, sausage was produced with or without varying levels of sodium nitrite and stored in the refrigerator for 15 days. As a result, cholesterol oxidation in sausage was inhibited by addition of sodium nitrite in a dose-dependent manner. This observation may be associated with inactivation of O(2)(-) radical and stabilization of polyunsaturated fatty acids (PUFAs). In fact, the levels of OxChol in sausage increased, accompanying the decrease of coexisting linoleic acid when sodium nitrite was not added to sausage meat. Thus, cholesterol oxidation in meat products seems to be considarably promoted by the oxidation of coexisting PUFAs. On the other hand, additive apple polyphenol also inhibited linoleic acid oxidation in sausage and then suppressed cholesterol oxidation through its radical scavenging effects. Therefore, apple polyphenol, having a large amount of an oligomer of catechin, may interfere with cholesterol oxidation in meat processing or storage of meat products through its antioxidative action and be useful as a new antioxitant for meat products when it is added to the original meat before processing.