南京市市售蔬菜硝酸盐和亚硝酸盐污染状况分析

目的:掌握南京市市售蔬菜中硝酸盐和亚硝酸盐的污染情况,为蔬菜供应安全及安全生产管理提供理论依据.方法:在南京市农贸市场和蔬菜批发市场共11个采集点采集44种蔬菜样品980份,用国标法(GB/T5009.33)分析蔬菜中的硝酸盐和亚硝酸盐含量.结果:不同种类蔬菜中硝酸盐含量差别较大,硝酸盐的含量依次为特菜类＞叶菜类＞茎类＞块根类＞瓜菜类＞甘蓝类＞果菜类＞豆类＞鳞茎类＞菌类;同一类别不同品种蔬菜中硝酸盐含量差别亦较大,从几倍至几十倍;检测的样品中,硝酸盐处于严重污染状态的占28.16％.蔬菜中亚硝酸盐含量相对较低,其含量与蔬菜的新鲜程度有关.结论:南京市市售蔬菜中硝酸盐污染较为严重,应引起足够重视,加强监督管理.     

熟肉制品中亚硝酸盐风险评估定量暴露评估模型的建立

根据熟肉制品随储存时间的变化而导致亚硝酸盐残留量的变化的试验结果,建立了亚硝酸盐含量的预测模型为y=2.5039+1.0372x1-3.5950x2。根据预测模型建立亚硝酸盐定量暴露评估模型,从而判断指出某市熟肉制品总体上是安全的,但同时也存在着一些潜在健康风险。     

2009～2011年邹城市城区凉皮、凉粉、面筋中亚硝酸盐含量调查

[目的]了解2009～2011年邹城市城区凉皮、凉粉、面筋中亚硝酸盐含量。[方法]采用自制发明定性试纸条的制备方法,现场定性后实验室按GB/T 5009.33-2008食品中亚硝酸盐与硝酸盐的测定定量。[结果]2009～2011年共检测了77份凉皮、53份面筋、20份凉粉中的亚硝酸盐含量,总的合格率为31.33%,其中2009年的合格率为24.53%;2010年的合格率为30.61%;2011年的合格率为39.58%。3年测定凉皮的亚硝酸盐含量平均值分别为36.10、30.80、19.70mg/kg,合格率分别为14.81%、19.23%、33.33%;面筋的平均值分别为25.30、22.60、9.20mg/kg,合格率分别为33.33%、41.18%、44.44%;凉粉的平均值分别为7.50、7.80、6.50mg/kg,合格率分别为3/8、3/6、3/6。凉皮平均值最高,合格率最低,面筋次之,但都逐年下降,合格率逐年升高。2009和2010年凉皮、面筋、凉粉进行比较,总的平均值差异无统计学意义(P>0.05),面筋、凉粉的合格率差异有统计学意义(P<0.05)。2009和2010年与2011年凉皮、面筋、...     

一起亚硝酸盐食物中毒的现场流行病学调查

目的了解人为投毒引起的亚硝酸盐食物中毒的特点和基本的现场流行病学调查方法。方法现场流行病学调查和盐酸萘乙二胺法及进口试纸条法检测样品中的亚硝酸盐。结果经确诊,累计报告29名患者,临床症状主要以缺氧和紫绀为主,其中6名患者的高铁血红蛋白比例（FmetHb％）超过10％。所有患者发病前三天只有一个共同餐次,平均潜伏期34min,潜伏期短,发病急促,且分别进食不同的食物而发病,在6份患者的呕吐物、4份剩余食物和2份鸡味粉中检出亚硝酸盐的含量严重超标。结论此次食物中毒为人为投放大量亚硝酸盐引起,具有隐蔽性强、临床症状重和现场取证难等特点。     

Intracerebroventricular administration of nitric oxide-sensitive guanylyl cyclase inhibitors induces catalepsy in mice

Rationale Catalepsy is a preclinical test that predicts extrapyramidal symptoms in humans. It models symptoms of acute extrapyramidal side effects induced at the beginning of antipsychotic treatment. Nitric oxide (NO) plays a role in a series of neurobiological functions underlying behavior. For example, inhibition of NO synthesis disrupts rodent exploratory behavior and induces catalepsy. Although several effects mediated by NO involve the activation of soluble guanylyl cyclase (sGC), the transduction mechanism of the catalepsy-inducing effect of NO has not yet been investigated. Objectives The study was designed to test if intracerebroventricular (i.c.v.) microinjection of NO-sensitive inhibitors of sGC (NO-sGC) induces catalepsy in mice similar to that induced by NO synthase (NOS) inhibitors. Exploratory behavior was tested in the open field. In addition, the effects of a NOS inhibitor on oxidative metabolites of NO were measured in the striatum. Materials and methods Drug effects were examined in the hanging-bar test after the following i.c.v. treatments: oxadiazolo-quinoxalin (ODQ, 30–300 nmol) or methylene blue (MB, 3–100 nmol), selective and nonselective sGC inhibitors, respectively, or 7-nitroindazole (7-NI, 3–90 nmol) and G-nitro-l-arginine methyl ester (l-NAME, 3–90 nmol), selective and nonselective neuronal NOS inhibitors. To test if the effects were related to interference with the NO system, additional groups received 7-NI (30 nmol), ODQ (100 nmol), or L-NAME (90 nmol) preceded by l-arginine (l-arg, 30–100 nmol, i.c.v. 30 min before). A possible interference of ODQ and 7-NI on exploratory behavior was tested in an open field. The concentration of nitrites and nitrates (NO _x ) in striatum homogenates was measured by the Griess reaction. Results Both NO-sGC and NOS inhibitors induced catalepsy in mice that lasted for at least 2 h. The range of effective doses of these drugs, however, was limited, and the dose–effect curves had an inverted U shape. The cataleptic effect induced by l-NAME was inversely correlated with NO _x products in the striatum. The cataleptic effect of 7-NI and ODQ was prevented by pretreatment with l-arginine. No drug changed exploratory behavior in the open field. Conclusion This study showed that pharmacological disruption of the endogenous NO-sGC signaling in the central nervous system induces long-lasting catalepsy in mice. Moreover, the cataleptic effect of NOS inhibition correlates with the decrease in NO _x products formation in the striatum. The results give further support to the hypothesis that NO plays a role in motor behavior control mediated, at least in part, by cyclic guanosine monophosphate production in the striatum.     

Effect of Rhizoma Polygonati on 12-O-tetradecanoylphorbol-acetate-induced ear edema in mice

Ethnopharmacological relevance

Rhizoma Polygonati is originated from the dried rhizomes of Polygonatum sibircum Red. It has long been used in traditional Chinese medicine for the treatment of inflammatory disorders.

Aim of the study

The present study aims to investigate the anti-inflammatory effect of aqueous extract of Rhizoma Polygonati (ERP) in a mouse model of inflammation induced by 12-O-tetradecanoylphorbol-acetate (TPA).

Materials and methods

The anti-inflammatory effect was evaluated by measuring the ear thickness and activity of myeloperoxidase (MPO). The anti-inflammatory mechanism was explored by determining the protein and mRNA levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6.

Results

The results showed that ERP significantly decreased the ear thickness and MPO activity in mouse model of inflammation induced by TPA. In addition, ERP also remarkably inhibited the protein and mRNA levels of iNOS, COX-2, TNF-α, IL-1β, and IL-6.

Conclusions

These results indicate that ERP has potential anti-inflammatory effect on TPA-induced inflammatory in mice, and the anti-inflammatory effect may be mediated, at least in part, by inhibiting the mRNA expression of a panel of inflammatory mediators including iNOS, COX-2, TNF-α, IL-1β, and IL-6.     

催化荧光法测定水中痕量亚硝酸根

基于在硫酸介质中 ,痕量亚硝酸根可催化溴酸钾氧化中性红褪色的反应 ,建立了一种催化荧光法测定痕量亚硝酸根的新方法 ,并研究了方法的动力学条件和多种常见离子的干扰情况。方法的选择性和灵敏度较高。亚硝酸根的线性范围为 0 .0 2～ 5 ng/ ml。方法的检出限 CL为 0 .0 1 3 ng/ ml。用于水中痕量亚硝酸根的测定 ,结果满意     

水样中亚硝酸盐的高效液相色谱测定法

目的：建立水样中亚硝酸盐的高效液相色谱分析方法。方法：用间接紫外－高效液相色谱法测定水样中痕量亚硝酸盐，以甲醇－0．10mol/L邻苯二甲酸（用0．10mol/L氢氧化钠调pH=8.6)5 95为流动相，采用ODP色谱柱，水样直接过滤处理法。结果：测定波长270nm，流量0．9ml/min，测定亚硝酸盐的线性范围为0．0－20．0μg/ml，精密度为3．9％，平均回收率为99．9％，检测限为0．001μg/ml，结论：本法可用于生活饮用水，纯净水及矿泉水中微量亚硝酸盐的测定。     

Relationships between NOS2 and HO-1 in liver of rats with chronic bile duct ligation.

An increased expression and activity of the heme oxygenase-1 (HO-1) in the liver has been observed in models of hepatic damage. Nitric oxide (NO) seems to be involved in HO-1 regulation. The aim of this work is to assess HO-1 induction and heme oxygenase (HO) activity in rats with bile duct ligation (BDL). We have assessed the effect of chronic inhibition of the NO synthesis by N(G)-nitro-l-arginine methyl ester (l-NAME) on HO-1 induction and HO activity. In the BDL animals, compared with sham-operated ones, we found an increased plasma nitrite and bilirubin concentration, and a marked liver expression of inducible nitric oxide synthase and HO-1, assessed by both Western blot and immunohistochemistry. Chronic l-NAME treatment prevented plasma nitrite increase in animals subjected to BDL. BDL animals treated with l-NAME, compared with untreated BDL rats, showed an important decrease in HO-1 expression and in HO activity (assessed as a decreased plasma bilirubin and bilirubin excretion). In conclusion, our experiments show parallel changes in expression and activity of HO-1 and NOS2 activity in the BDL model of liver damage and suggest that increased NO production is involved in HO-1 overexpression.     

硫氰酸铁-亚硝酸盐催化分光光度法测定水中碘

目的探讨取代剧毒试剂三氧化二砷（AS2O3）的水中碘的催化分光光度法。方法在稀硝酸介质中,研究碘催化硫氰酸铁褪色反应的适宜条件,建立测定水中微量碘含量的催化动力学光度法。结果方法的线性范围为6~100μg/L,相关系数r=-0.9997,检出限为1.77μg/L碘（取样量1mL,1.77ng碘）,回收率在97.20%~99.95%。结论本方法较砷铈催化分光光度法检测水中碘的精密度和准确度结果满意,可完全不使用剧毒物质三氧化二砷,减小了对检测人员健康的损害和环境污染的风险。