The hedonic impact and intake of food are increased by midazolam microinjection in the parabrachial nucleus

Benzodiazepines have been reported to induce eating when administered into the brainstem of rats (either the fourth ventricle or the parabrachial nucleus). Benzodiazepines in the brainstem also have been reported to enhance the hedonic impact of taste, as measured by hedonic/aversive taste reactivity patterns, when administered to the fourth ventricle. The present study examined whether the parabrachial nucleus in particular is a brainstem site of the benzodiazepine-produced enhancement of eating and palatability. Food intake (cereal mash) was measured after brainstem microinjections of midazolam or vehicle (0.0, 7.5, and 15.0 microg) into the parabrachial nucleus, the nucleus of the solitary tract, the pedunculopontine tegmental nucleus, or the fourth ventricle (60 microg). We used the taste reactivity paradigm to measure hedonic/aversive affective reactions elicited from rats by oral infusions of a bittersweet solution (7% sucrose-0.01% quinine). Positive hedonic reactions and negative aversive reactions to sucrose-quinine were also measured after microinjections of midazolam (0.0, 7.5, and 15 microg) into the parabrachial nucleus. Midazolam increased food intake and selectively enhanced positive hedonic taste reactivity patterns to the bittersweet solution when microinjections were delivered to the parabrachial nucleus. When administered to the other brainstem sites at the same doses, however, midazolam had no effect. We therefore conclude that the parabrachial nucleus can mediate the benzodiazepine-induced enhancement of the hedonic impact of taste as well as mediating the enhancement of eating behavior.     

两种维生素C测定方法的比较

目的 :研究 2 ,6 -二氯酚靛酚法与 2 ,4 -二硝基苯肼法测定蔬菜和水果及尿液中抗坏血酸含量之间的关系。方法 :对蔬菜和水果样品 ,及扬州医学院大学生和市某幼儿园儿童 3h尿总量 ,收集前受试者排空小便后 ,口服 5 0 0 m g维生素C片剂 ,饮水 4 0 0 ml。分别用上述两种方法进行测定样品中维生素 C。结果 :在冬瓜和黄瓜中 ,两种方法所测维生素 C结果差异无统计学意义 ,而在黄豆芽和绿豆芽中 ,两种方法测定结果差异有统计学意义。对于尿样中的维生素 C,2 ,6 -二氯酚靛酚法所测定结果明显高于 2 ,4 -二硝基苯肼法 ,两者有明显的相关关系 ,其回归方程为 Y=- 14 .5 7 0 .5 2 9X。结论 :当用 2 ,6 -二氯酚靛酚法测定绿豆和黄豆芽中的维生素 C时 ,其误差较大。但对于尿中维生素 C,如果使用 2 ,6 -二氯酚靛酚法 ,则须用回归方程进行推断     

2002年上海市居民营养与健康状况调查

[目的]了解上海市居民的膳食结构、营养现况和营养相关疾病,为国家制定相关政策、指导居民合理饮食提供依据。[方法]本次调查是家庭抽样调查,采用分层多阶段整群随机的方法,调查包括询问调查、医学体检、实验室检测和膳食调查等。[结果]上海市居民动物性食物消费量增加,达人均408.9g/d;奶类、水果消费量基本达到推荐量,分别为人均100.3、108.1g/d;但畜禽肉类、油脂和盐消费过多,分别为人均136.8、49.6、9.9g/d;谷类食物偏低,为人均339.0g/d;蔬菜消费不足,为人均309.9g/d。居民能量、蛋白质、脂肪及大多数营养素的摄入量基本充足,但钙、维生素B1仍不足。营养不良、贫血患病率较低,分别为6.4%、7.6%;但超重、肥胖、高血压、糖尿病、血脂异常患病率较高,分别为29.2%、3.8%、31.3%、8.1%、25.3%。[结论]上海市居民膳食状况有较大提高,但膳食结构不尽合理;基本营养素摄入得到满足,但某些营养素依然缺乏;营养相关性慢性病患病率将是上海市面临的重要公共卫生问题。     

蔬菜中氨基甲酸酯类农药残留的HPLC/MS测定研究

目的建立简便、灵敏、准确的高效液相色谱电喷雾质谱测定蔬菜中氨基甲酸酯残留的检测方法.方法样品经乙腈提取、甲醇二氯甲烷(199 v/v)溶解后,用固相萃取小柱进行净化、提纯.选用Pickering C8(250 mm×4.0 mm×5 μm)作为分析柱,甲醇/酸化水(内含0.1%乙酸)梯度洗脱,通过选择性离子监测(SIM)及电喷雾电离离子化技术进行测定.结果线性范围为50.0～1 500.0μg/L,定量检测下限为4.8～8.6μg/kg,方法回收率为78.5%～108.4%,标准偏差为4.6%～7.9%,RSD均小于8%.结论该法灵敏度高、操作简便、快速,适用于实际样品的测定.     

北京地区居民丙烯酰胺膳食摄入量的研究

目的应用24小时回顾询问法,估计北京地区居民丙烯酰胺摄入量。方法采用GC-MS方法检测北京市场上购买的24类食物,并应用检测结果计算2460份食谱(820人×3天)的丙烯酰胺含量。结果北京地区居民的丙烯酰胺的平均摄入量为(μg/d):男性18·6,女性16·6;97·5分位数为(μg/d):男性59·0,女性50·4。应用每kg体重计算均值[μg/(kgbw·d)]:男性0·282,女性0·284;97·5百分位数[μg/(kgbw·d)]:男性0·898,女性1·007。各餐丙烯酰胺摄入比例为:早餐20·48%,午餐38·99%,晚餐39·42%,零食1·17%。结论午餐和晚餐食品是北京地区居民丙烯酰胺的主要来源,改变北京地区居民的正餐的烹调方式和控制北京传统早餐食品中的丙烯酰胺含量是减低北京地区居民丙烯酰胺暴露量的主要措施。     

西南地区飞行人员吸烟饮酒与高血压的关系研究

目的:研究西南地区民航飞行员吸烟、饮酒与高血压的关系。方法:采用描述流行病学方法对西南地区1350名23~60岁的飞行员进行血压的测量和吸烟、饮酒的调查,采用分层和标准化的方法进行统计分析。结果:吸烟饮酒组及单一饮酒组的高血压标化患病率(14.0%及12.4%)显著高于单一吸烟组和对照组(8.0%及6.1%)。吸烟饮酒组与单一饮酒组的标化患病率差异无统计学意义。单一吸烟组与对照组间标化患病率差异无统计学意义。结论:饮酒可能与西南地区飞行人员高血压的发病有关,而吸烟与高血压关系不明显。     

2003～2004年苍山县部分蔬菜农药残留量检测分析

[目的]了解苍山县蔬菜农药残留有关情况,为有效控制蔬菜农药残留,提供科学依据.[方法]2003～2004年对苍山县部分蔬菜批发市场、种植基地及零散摊点进行随机抽样检测,用农药速测卡结合色谱法测定其中的有机磷类农药.[结果]共检测各种蔬菜827份,农药残留阳性的98份,阳性率为11.85%.[结论]我县蔬菜农药残留问题比较严重,应进一步加强监督管理.     

Seasonal changes in the expression of neuropeptide Y and pro-opiomelanocortin mRNA in the arcuate nucleus of the ovariectomized ewe: relationship to the seasonal appetite and breeding cycles

Sheep experience well-documented seasonal changes in reproductive activity and voluntary food intake (VFI). Within the hypothalamus, neurones that express neuropeptide Y (NPY) and pro-opiomelanocortin (POMC) have been implicated in the regulation of reproduction and appetite. In this study, we aimed to determine the extent to which the expression of these two neuronal systems is linked to the seasonal reproductive cycle and/or the seasonal appetite cycle. VFI in our sheep reaches a nadir in August with no difference occurring between December and February. We examined the brains of ovariectomized (OVX) female sheep (n=5-7) that were killed during the breeding season (February) or during the early or late nonbreeding season (August and December, respectively). The brains of these animals were perfused with paraformaldehyde and processed for in situ hybridization histochemistry, using ribonucleotide probes labelled with 35S. The number of NPY and POMC cells and the number of silver grains per cell were counted using an image analysis system. For NPY, the number of cells counted in the arcuate nucleus/median eminence region and the number of silver grains per cell was significantly lower in animals killed during August than in animals killed in February or December. The number of grains per cell over NPY cells was also significantly lower in animals killed during August. For POMC, the number of cells was lower in February than in August and December. Similarly, the number of grains per cell for POMC were lower in February than in August and December. VFI was significantly lower in animals during August than at other times of the year. We conclude that in OVX ewes: (i) NPY gene expression is lower at the time of the year when VFI is reduced and (ii) POMC gene expression is greater at the time of the nonbreeding season than during the breeding season. Because these results were obtained in OVX animals, the changes appear to be independent of alterations in the secretion and/or action of ovarian steroids. Thus, the activity of NPY neurones appears to relate to changes in appetite whereas changes in POMC expression may be relevant to the seasonal breeding cycle.     

Bioactive nutrients - Time for tolerable upper intake levels to address safety

There is increasing interest by consumers, researchers, and regulators into the roles that certain bioactive compounds, derived from plants and other natural sources, can play in health maintenance and promotion, and even prolonging a productive quality of life. Research has rapidly emerged suggesting that a wide range of compounds and mixtures in and from plants (such as fruits and vegetables, tea and cocoa) and animals (such as fish and probiotics) may exert substantial health benefits. There is interest in exploring the possibility of establishing recommended intakes or dietary guidance for certain bioactive substances to help educate consumers. A key aspect of establishing dietary guidance is the assessment of safety/toxicity of these substances. Toxicologists need to be involved in both the development of the safety framework and in the evaluation of the science to establish maximum intake/upper limits.