丙烯酸甲酯的毒性研究

本文报告丙烯酸甲酯的急性和慢性毒性。主要急性毒作用是刺激作用及对中枢神经系统的作用。对大鼠、小鼠和家兔的LC_(50)分别为6400mg/m~3、8800mg/m~3及6800mg/m~3。对大鼠经口LD_(50)为0.27g/kg。对家兔经皮LD_(50)为0.7ml/kg。引起家兔呼吸数减少的急性阈浓度为80mg/m~3。对人的嗅阈为1.5mg/m~3,刺激阈浓度为31mg/m~3。慢性染毒,在840mg/m~3和100mg/m~3组大鼠,动物体重增长缓慢、白细胞数减少、T淋巴细胞数减少,SGPT与SGOT有升高的趋势。20mg/m~3组,除白细胞数减少外,其余指标均未见改变。病理改变主要是肺、肝、肾等内脏器官充血、出血、炎症细胞浸润及细胞变性坏死。     

低剂量混合稀土常乐对大鼠血清胰岛素及肝细胞糖原的影响

目的 研究长期灌胃低剂量混合稀土常乐对大鼠血清胰岛素、血糖及肝细胞糖原的影响.方法 将Wistar大鼠随机分为两大组,即6月组和7月组,每组又分为对照组与混合稀土常乐组.混合稀土常乐组又分为4个剂量组:0.1、0.2、2.0、10.0mg/kg,每组30只大鼠,雌雄各半.混合稀土常乐组每日以灌胃方式给予上述不同剂量的混合稀土常乐,对照组给予等量0.9%生理盐水.6月组持续灌胃6个月,7月组于灌胃6个月后,停止给予混合稀土常乐及等量生理盐水,正常饲喂1个月.利用放射免疫分析技术和显微图像分析技术检测大鼠血清中胰岛素的水平、血糖水平和肝细胞糖原的水平.结果 给予混合稀土常乐6个月后,10.0 mg/kg组雌性、雄性大鼠胰岛素水平下降、血糖水平升高和肝细胞糖原的灰度值升高,与对照组比较,差异有统计学意义(P＜0.05).0.1、0.2、2.0mg/kg组雄性大鼠胰岛素水平升高、血糖水平下降和肝细胞糖原的灰度值下降,与对照组比较,差异有统计学意义(P＜0.05).灌胃6个月后,停药1个月检测,雌性、雄性大鼠各组胰岛素水平和肝细胞糖原的灰度值基本恢复正常.结论 低剂量混合稀土常乐长期作用可以引起大鼠血清中胰岛素水平和肝细胞糖原发生变化,这种变化可在短期内恢复正常;较低浓度的混合稀土常乐(0.1、0.2和2.0 mg/kg)可促进胰岛素分泌和肝细胞糖原合成.     

静脉注射士的宁对氯胺酮镇痛作用的影响

[目的]探讨甘氨酸受体与氯胺酮镇痛作用的关系。[方法]在热板、扭体法实验中,观察不同剂量的士的宁对氯胺酮小鼠痛阈及扭体次数的影响。[结果]腹腔注射氯胺酮10mg/kg对小鼠热板法痛阈无影响（P﹥0.05）,20、40mg/kg可使小鼠痛阈增加（P﹤0.05）;腹腔注射氯胺酮10mg/kg对小鼠扭体次数无影响（P﹥0.05）,20、40mg/kg均可使小鼠扭体次数减少﹙P﹤0.05）;静脉注射士的宁0.25μg对腹腔注射氯胺酮（40mg/kg）小鼠痛阈无影响﹙P﹥0.05）;0.5、0.75、1.0μg可使氯胺酮小鼠痛阈减少﹙P﹤0.05）;士的宁（0.25、0.5、0.75、1.0μg）静脉注射对氯胺酮（40mg/kg）小鼠的扭体次数无影响﹙P﹥0.05）。[结论]氯胺酮在热板法和扭体法中产生的镇痛作用是不相同的,提示前者可能涉及甘氨酸受体,而后者与甘氨酸受体关系不大。     

纳米氧化石墨烯对小鼠体内外急性毒性作用

目的通过体内和体外实验观察氧化石墨烯纳米颗粒的急性毒性作用。方法选择60只健康ICR小鼠,雌雄各半,随机分成6组,每组10只,以高纯水配制纳米氧化石墨烯,分别以剂量0 mg/(kg·bw)、3.125 mg/(kg·bw)、6.25 mg/(kg·bw)、12.5 mg/(kg·bw)、25.0 mg/(kg·bw)和50.0 mg/(kg·bw)进行纳米氧化石墨烯灌胃,观察动物一般状态及死亡情况;另取60只ICR小鼠,分为6组,在无菌条件下,以高纯水配制纳米氧化石墨烯,以剂量0 mg/(kg·bw)、1.0 mg/(kg·bw)、2.0 mg/(kg·bw)、4.0 mg/(kg·bw)、8.0 mg/(kg·bw)和16.0 mg/(kg·bw)进行尾静脉注射,观察动物一般状态及死亡情况。采用MTT法,以剂量为9.875 mg/(kg·bw)、18.75 mg/(kg·bw)、37.5 mg/(kg·bw)、75 mg/(kg·bw)、150 mg/(kg·bw)、300 mg/(kg·bw)和600 mg/(kg·bw)的氧化石墨烯与A549细胞进行共培养,观察细胞的生长状况并计算细胞的LC_(50)。结果纳米氧化石墨烯经口染毒途径未引起小鼠器官病理改变,无动物死亡;通过尾静脉注射对小鼠的LD_(50)为5.657 mg/(kg·bw),肺、肝、心组织血管内可见褐色纳米颗粒,但组织未见病理学变化;对A549细胞的LC_(50)为56.885μg/m L。结论未经修饰的纳米氧化石墨烯经尾静脉注射可导致动物死亡,并对A549细胞生长具有抑制作用。     

水源水中四氯化碳最高容许浓度的研究

四氯化碳经口中毒动物试验表明:急性中毒引起肝细胞膜脂质过氧化反应,P-450降低,SGPT 和肝甘油三脂增高,并且确认脂质过氧化是四氯化碳中毒重要起始反应;慢性中毒阈剂量为0.2mg/kg,形态学上的改变为肝细胞脂肪变、坏死和增生、亚细胞结构粗面内质网颗粒脱落,空泡反应,最大无作用剂量为0.02mg/kg,换算成浓度值为0.4mg/L,加上必要的安全系数,建议水源水中四氯化碳最高容许浓度为0.004mg/L。     

甲基丙烯酸甲酯的急性毒性和毒物动力学

本文报道了MMA不同染毒途经的急性毒性及阈浓度、皮肤粘膜刺激强度、对心血管系统的急性毒作用以及毒物动力学研究。实验表明,大鼠LC_(50)为45.5±1.56mg/L,LD_(50)为8507.0±14.7mg/kg,属低毒。皮肤粘膜刺激强度属中等,50mg/kg家兔静注可引起心律失常、血压下降。150mg/kg家兔静注在体内以一室开放形模型配置,毒物动力学特征是吸收快,分布广、周身分布,消除快,以肾外途径消除为主,主要通过非特异性酯酶的酶促代谢转化。     

水源水中四氯化碳最高容许浓度的研究

四氯化碳经口中毒动物试验表明:急性中毒引起肝细胞膜脂质过氧化反应,P-450降低,SGPT和肝甘油三脂增高,并且确认脂质过氧化是四氯化碳中毒重要起始反应;慢性中毒阈剂量为0.2mg/kg,形态学上的改变为肝细胞脂肪变、坏死和增生、亚细胞结构粗面内质网颗粒脱落、空泡反应,最大无作用剂量为0.02mg/kg,换算成浓度值为0.4m/L,加上必要的安全系数,建议水源水中四氯化碳最高容许浓度为0.004mg/L。     

乙二胺毒性研究

乙二胺急性毒性研究表明,小鼠和大鼠LD_(50)分别为950和840mg/kg;大鼠吸入致死浓度为607ppm,其靶器官为肺、肝、肾。亚急性吸入实验高浓度组(112ppm)动物出现肺、肝、肾病理改变和非特异性免疫功能降低,其阈浓度为2.5ppm。致敏实验豚鼠皮肤发生以单核细胞浸润为主的变态反应性炎症改变,属迟发型过敏反应。     

混合稀土“常乐”对大鼠肾脏组织的氧化损伤

目的研究长期口服低剂量混合稀土"常乐"对大鼠肾脏自由基防御机能的影响。方法将清洁级Wistar大鼠随机分为对照组和5个不同剂量的混合稀土"常乐"组(0.1、0.2、2.0、10.0、20.0mg/kg),每组30只,雌、雄各半。混合稀土"常乐"组每日以灌胃方式给予上述不同剂量的混合稀土"常乐",对照组给予等量0.9%生理盐水。持续灌胃6个月后,检测肾组织中Cu-Zn超氧化物歧化酶(Cu-ZnSOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活力和脂质过氧化物(LPO)含量。结果与对照组比较,雄性大鼠20.0、10.0mg/kg组和雌性大鼠20.0mg/kg组Cu-ZnSOD和CAT的活力显著降低,差异有统计学意义(P<0.01),而GSH-Px的活力和LPO的含量显著升高,差异有统计学意义(P<0.01)。与对照组比较,雌性、雄性大鼠0.2、0.1mg/kg组Cu-ZnSOD的活力显著升高,差异有统计学意义(P<0.01);LPO的含量显著降低,差异有统计学意义(P<0.01);GSH-Px的活力差异无统计学意义(P>0.05)。结论较高剂量的混合稀土"常乐"导致大鼠肾脏脂质过氧化反应增强,清除自由基的能力下降;较低剂量的混合稀土"常乐"能抑制自由基的产生,降低体内过氧化物的含量,提高抗氧化酶的活力。     

抗虫灵对大 鼠全血和人红细胞膜乙酰胆碱酯酶的抑制作用

目的应用Ellman法或羟胺法检测乙酰胆碱酯酶(AChE)活性.方法研究有机磷杀虫剂抗虫灵对大鼠全血和人红细胞膜AchE活性的影响.结果雄性大鼠每天经口给以抗虫灵6.81mg/kg连续5d可引起全血AChE活性明显下降;动物亚慢性90d染毒后,雄性中剂量(0.25mg/kg)和高剂量(1.00mg/kg)组动物与雌性低剂量(0.05mg/kg)和高剂量(1.00mg/kg)组动物全血AChE活性明显下降;体外试验发现,抗虫灵在所试验的5×10-8～5×10-8mol/L的浓度范围内对人红细胞膜AChE活性都有明显抑制作用,并有剂量和时间依赖性,而且这种抑制为不可逆抑制.结论抗虫灵对AChE活性的抑制是其毒作用的重要机理,符合有机磷杀虫剂毒作用的一般规律.     

包头市出产蔬菜水果稀土元素含量检测及健康风险评价

目的 本研究通过测定包头市出产蔬菜水果中稀土元素的含量,进行居民摄入健康风险评价。方法 应用湿法消解-电感耦合等离子体质谱仪（ICP - MS）,测定蔬菜水果中17种稀土元素含量,比较各类蔬菜水果的均值,对稀土元素进行相关性分析,并使用ADI方法对蔬菜水果中稀土元素可能对人体产生的健康风险进行安全评价。结果 2019年包头市出产蔬菜水果中稀土元素含量范围为0.00～2.03 mg/kg,平均含量0.39 mg/kg。叶菜类的稀土元素平均含量最高,其次是水果,最低是根菜类,Ce、Sm和Nd 3种稀土元素之间均具有较强相关性,包头市居民食用蔬菜水果摄入稀土元素日平均摄入量为0.0035 mg/(kg·d),远低于安全剂量标准。结论 2019年包头市出产蔬菜水果中稀土元素含量较低,包头市居民通过食用本地出产蔬菜水果摄入稀土元素量是安全的。     

Occurrence of nitrates and nitrites in certain frozen fruits, jams, stewed fruit and fruit-vegetable juices for children and in certain types of bee honey

Nitrates and nitrites were evaluated spectrophotometrically by the method of Griess reaction, with previous reduction of nitrates to nitrites in a column filled with cadmium dust. The content of nitrates in frozen fruit (strawberries, black and red currant and plums) ranged from 2.50 to 57.38 mg KNO3/kg, with the highest content in garden strawberries. In cherry, strawberry, black and red currant jams the concentrations were from 6.30 to 97.38 mg KNO3/kg, the highest content was in cherry jam. In plum jam nitrates were found in low amounts from 11.65 to 12.09 mg/kg. In "Bobofrut" juices the nitrate content was higher than in the above products, ranging from 26.37 to 182.75 mg KNO3/kg. Nitrite content in all these groups of products was low, not exceeding 1 mg NaNO2/kg, with the exception of plum jam where the maximal value was found 1.65 mg NaNO2/kg. In stewed fruit and herb syrups and in honey nitrates ranged from 1.0 to 94.5 mg KNO3/kg. Nitrite content ranged from 0.17 to 1.92 mg/kg in herb syrups, from 0.0 to 1.20 mg/kg in stewed fruit, and from 0.0 to 0.40 mg NaNO2/kg in honey. The study showed that higher levels of nitrates were present as a rule in vegetable juices. However, the found concentrations were not harmful to the health of children, although this is possible in the case of carrot juice, especially when kept at room temperature for 24 hours.     

混合稀土硝酸盐对仔鼠免疫功能的影响

目的：了解混合稀土硝酸盐[RE(NO3)3]能否经胎盘进入仔鼠体内及RE（NO3）3对仔鼠免疫功能的影响。方法：小鼠妊娠7－8d开始经口灌胃，分别给予2，20，200mg/kgRE（NO3）3，对照组给与蒸馏水，直至生下仔鼠。采用电感耦合等离子体质谱法（ICP－MS）检测F1代仔鼠体内稀土元素镧（La）、铈（Ce）、镨（Pr）、钕（Nd）的含量；分别测定刚离乳及离乳3周仔鼠免疫器官重量、脾抗体形成细胞数（IgM-PFC／脾）、迟发型变态反应（DTH）和巨噬细胞功能。结果：妊娠期母鼠经口灌胃RE（NO3）3后，20．0mg/kg组F1代仔鼠刚出生时体内稀土元素La高于对照组（P＜0．05）；200．0mg/kg组F1代仔鼠刚出生时体内稀土元素La、Ce、Pr、Nd含量均明显高于对照组（P＜0．05）。F1代仔鼠刚离乳时，20．0mg/kg组仔鼠脾脏重量明显高于对照组（P＜0．05）；2．0mg/kg RE(NO3)3可明显增加IgM-PFC/脾（升高82．2％）；2．0，20．0mg/kg组碳粒廓清指数K值和吞噬指数α值均明显高于对照组（P＜0．01，P＜0．05）；2．0mg/kg RE（NO3）3对DTH有明显升高作用（P＜0．05）。F1代仔鼠离乳后3周各剂量组仔鼠脾脏重及其脏体比均明显高于对照组（P＜0．05）；200．0mg/kg RE（NO3）3对IgM-PFC／脾有明显的抑制作用（抑制率为36．9％），且对碳粒廓清指数K值和吞噬指数α也有明显的抑制作用（P＜0．05）。各剂量组DTH未见有明显改变。结论：RE（NO3）3可经胎盘转运进入仔鼠体内，且可对仔鼠免疫功能产生一定的影响，这些影响可能是RE（NO3）3经胎盘转运进入仔鼠体内的结果。     

微波消解/ICP-MS法测定胎儿肾脏和小脑中稀土元素的研究

目的　测定深圳市正常中期引产胎儿肾脏和小脑中多种稀土元素的含量 ,为研究人类生命不同阶段稀土元素水平提供基础资料。方法　样品经HNO3+H2 O2 微波消解系统消解后 ,用电感耦合等离子质谱(ICP MS)检测胎儿肾脏和小脑中La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu 14种稀土元素。结果　所检测的 14种稀土元素 ,La在肾脏中的含量最高为 0 4 2 0 μg kg,Ce在小脑中的含量最高为 0 .36 3μg kg,Yb在肾脏和小脑中的含量均最低 ,分别为 0 . 10 3μg kg和 0. 0 98μg kg。在胎儿肾脏和小脑中 ,轻稀土元素 (La～Sm)的总含量分别为 1 .4 2 7μg kg、1. 2 36 μg kg ,中稀土元素 (Eu～Gd)的总含量分别为 0 . 4 6 9μg kg、0 .4 32 μg kg ,重稀土元素 (Tb～Lu)的总含量分别为 1 .387μg kg、1 .4 18μg kg。 结论　上述 14种稀土元素均可在胎儿肾脏和小脑中检出 ,并具有一定的分布特点。     

Presence of nitrates and nitrites in baker's products and in certain other flour products

The results of the study demonstrated that the content of nitrates and nitrites in various baker's products varied from 0.96 (in wheat rolls and baguettes) to 44.07 mg KO3/kg in pumpernickel bread. In wholemeal bread, village bread, tourist bread, rye brown bread and Graham bread the content of these compounds was from 1.46 to 27.10 mg KNO3/kg. The mean content of nitrites in these bread sorts was 1.76 mg NaNo2/kg, range 0.10-4.40 mg NaNo2/kg. In white wheat flours (Wroc?aw flour, cake flour and Poznań flour) the content of nitrates ranged from 1.10 to 19.08 mg KNO3/kg, and in the dishes produced from them in household was from 0.50 to 16.33 mg KNO3/kg. The content of nitrites in these flours was in the range from 0.00 to 4.16 mg NaNo2/kg, and in the products prepared from them it was from 0.00 to 1.60 mg NaNO2/kg. Eleven types were tested also of popular biscuits, wafers, gingerbread and hard cakes in which the content of nitrates was from 3.66 to 17.72 mg/kg, and that of nitrites was from 0.00 to 8.80 mg NaNo2/kg. Considering the average consumption of these products per one person in the seashore region and the mean values of nitrates and nitrites it was calculated that they provided daily about 3.9 mg KNO3 and 0.4 NaNo2, that is about 1.8% of nitrates and 7.7% of nitrites consumed by adults in daily food ration.     

江西省某稀土矿区粮食中稀土元素含量及人群健康风险评价

目的 了解稀土矿区粮食中稀土元素含量,对不同年龄段人群粮食中稀土暴露量及健康风险进行评价。方法 采集稀土矿区和对照区居民粮食样品428份,通过电感耦合等离子体质谱法（ICP-MS）测定其稀土元素的含量,应用美国环保署（USEPA）的健康风险模型开展健康风险评价。结果 矿区和对照区粮食中总稀土元素的平均值分别为99.03μg/kg和34.21μg/kg,差异具有统计学意义（t=4.81,P=0.001）。大米的稀土元素含量最高（矿区和对照区分别为102.79μg/kg和35.28μg/kg）,而玉米的稀土元素浓度最低（矿区和对照区分别为76.98μg/kg和26.95μg/kg）。健康风险评估表明,通过摄入粮食消费计算的每日稀土元素摄入量低于可接受的每日摄入量（70μg/(kg·d)）。结论 矿区粮食中稀土元素对不同年龄段的人群健康的风险较低,但应注意持续暴露下稀土元素对儿童的健康的影响。     

Effect of a differentiated additive KNO3 on the quality of Zu?awski cheese. I. Nitrate changes in maturing Zu?awski cheese

18 gyle of cheese in three experimental variants were produced: O variant--control product without additive KNO3; 1 variant--with 0.01% of additive KNO3; 2 variant--with 0.02% of additive KNO3. It was found that raw and pasteurized milk was not an essential source of nitrates. During the summer and autumn cycles of production it was noted respectively: 0.0-0.8 mg NO3-/kg and 0.0-7.4 mg NO3-/kg. Content of NO3- ions in cheese starter approximated their content in raw milk. However, content of nitrates in milk after preparing depended mostly on the quantity of added saltpeter. The cheese made without saltpeter was characterized by low level of nitrates, not exceeding 4.2 mg NO3-/kg, and by vestigial presence nitrites. Whereas the cheese made with additive KNO3 included to 40 mg NO3-/kg for 0.01% of additive KNO3 and to 80 mg NO3-/kg for 0.02% of additive KNO3. It was found that the most intense reduction of nitrates in cheese (to 75%) occurred between the phase of pressing and up to the first two weeks of its ripening. After four weeks' ripening process the level of nitrates in cheese became stabilized independently of the quantity of additive KNO3. After six weeks' ripening process, that is when the cheese is sent into consumption, the level of nitrates and nitrites was quite low and did not exceed 3.0 mg NO3-/kg and 1.2 mg NO2-/kg. Manufactured cheese met the requirements of FIL/IDF while taken into consideration the content of nitrates and nitrites.     

陕西省蔬菜中稀土元素的含量特征及评价

目的 调查陕西省蔬菜中稀土含量水平,并评估其对人体健康的影响。方法 采用微波消解-电感耦合等离子体质谱法测定蔬菜中16种稀土元素含量。以GB 2762-2005《食品中污染物限量》为标准对蔬菜中稀土含量进行评价。采用点评估法计算陕西省居民通过蔬菜摄入稀土含量。结果 陕西省蔬菜中稀土氧化物均值为0.274 1 mg/kg,含量范围在0.003 3~2.661 8mg/kg。不同种类蔬菜的稀土污染情况存在显著差异,叶菜类、鳞茎类稀土超标率分别为19.6%和17.4%,其余类别蔬菜均未超标。单因子污染指数评价结果叶菜类为警戒线、尚清洁,其余各类蔬菜均为安全、清洁。16种稀土元素在蔬菜中含量差异较大,铈、钕、镧、钇含量高,表现为轻稀土相对富集。陕西省居民通过蔬菜摄入稀土氧化物的含量均值为67.10μg/d,占ADI的比例为1.60%。结论 陕西省蔬菜存在一定的稀土污染情况,居民通过蔬菜摄入稀土的量是安全的。     

Content of nitrates and glycoalcaloids in mature tubers of Polish potato

Nitrates and glycoalcaloids (TGA) content in mature tubers of 29 potato table cultivars of different earliness were examined during 1992-1998. Excess of nitrates (more than 250 mg NaNO3/kg of product--the upper limit for food safety in Poland) was found in 24 tuber samples what makes 16% of total number (154) tested samples. Samples with the highest amounts of nitrates belonged mainly to very early and early cultivars. TGA concentrations lower than the upper limit TGA for food safety (200 mg/kg of product) were estimated in all 129 tested tuber samples. Only in 8 samples TGA content was between 100 and 140 mg/kg of product what could cause bitter taste.     

Evaluation of nitrates and nitrites food intake in Polish households in years 1996-2005

The studies on nitrates and nitrites food intake in years 1996-2005 were curried out in six types of households. Using household budget data and literature mean values of nitrates and nitrites contents in food products food intakes of these compounds were calculated and compared to acceptable daily intake (ADI) taking into consideration main sources of them. The obtained results indicated that the mean nitrate and nitrite food intakes did not exceed ADI and were relatively low 132-190 mg NaNO3/per person/day (56.8% ADI), and 3.0 to 3.5 mg NaNO2/per person/day (58% ADI). Nitrate and nitrite food intakes depended on type of household being highest at pensioners and retired persons and farmers. The main sources of nitrates were vegetables and their products supplied 89% of nitrates whereas meat and meat products supplied 69% of nitrites.