氟虫腈对黑胸散白蚁的药效观察

目的了解氟虫腈对黑胸散白蚁的药效。方法采用滤纸法了解接触毒性,采用滤纸法和木块法了解驱避性,采用木块法了解选择取食和强迫取食毒性。结果氟虫腈对黑胸散白蚁有一定的致死作用。同时,在较高浓度下,氟虫睛对黑胸散白蚁具有一定的驱避性。结论可使用50mg／L及以下浓度的氟虫腈防治黑胸散白蚁。     

A method to induce stable atopic dermatitis-like symptoms in NC/Nga mice housed with skin-lesioned mice

BACKGROUND: Itching is a characteristic symptom in various forms of dermatosis, especially atopic dermatitis; consequently it is a major diagnostic criterion. All features are similar to events seen in patients, hence NC/Nga mice are considered to be a suitable model of human atopic dermatitis. However, there were data spreads in commencing time and the degree of skin lesions in NC/Nga mice. OBJECTIVES: In the present study, we attempted to improve experimental conditions to induce stable skin lesions and to establish a more appropriate method. Methods NC/Nga mice were kept together with skin-lesioned mice during the experiment period (mixed-NC mice). The dermatitis scores of face, ears and rostral back were assessed. Scratching behaviour was measured using an apparatus, MicroAct (Neuroscience, Tokyo, Japan). Transepidermal water loss (TEWL) and serum total IgE levels were also measured. To observe the presence of mites, the skin of the rostral backs of the mixed-NC mice was stripped using cellulose tape. We also investigated the effects of fipronil (Wako, Osaka, Japan), an acaricidal compound, on skin lesions and scratching behaviour of these mixed-NC mice. RESULTS: In mixed-NC mice, skin lesions appeared from 2 weeks, worsened gradually and reached peak levels of a dermatitis score in 8 weeks. Scratching behaviour increased significantly from day 3. TEWL also increased from day 3, but total IgE increased from day 7. Mites were observed on the rostral backs of mixed-NC mice from day 3, and all mice had these mites on day 28. Giving pretreatment with fipronil (Wako), the skin lesions and scratching behaviour of mixed-NC mice was significantly suppressed. CONCLUSIONS: The findings of the present study suggest that the method of being kept together with skin-lesioned mice can induce stable skin lesions and scratching behaviour at an early stage, without skin lesions. This method could help investigate a more stable evaluation of the effects on symptoms of atopic dermatitis, and mechanisms of the itching. It was considered that parasitism of mites, not allergic reactions, was the pathogenesis of skin lesions and scratching behaviour in mixed-NC mice.     

农药致癌性的研究进展

目的研究制备适合于蔬菜基质中农药残留检测的能力验证样品, 通过能力验证评价相关实验室检测能力。方法选择卷心菜为样品基质,采用冷冻干燥、标准添加的方式制备能力验证样品,通过随机抽样测定以评估样品的均匀性,通过观察样品42天内目标化合物测试结果变化以评估样品的稳定性。结果样品均匀性及稳定性检验符合预期效果,制备的能力验证样品定值准确。结论制备的联苯菊酯、溴虫腈和氟虫腈能力验证样品,可用于蔬菜中农药残留的能力验证和方法评价,结果满意。     

氟虫腈及其砜化物在兔体内的毒物代谢动力学

目的建立兔血浆中氟虫腈及其砜化物的高效液相色谱(HPLC)检测法,并研究其在兔体内的毒物代谢动力学,为氟虫腈中毒的临床诊断与治疗提供依据。方法氟虫腈3 m.gkg-1兔耳缘静脉注射后不同时间取血,采用高效液相色谱法检测血浆中氟虫腈及其砜化物的浓度,计算毒动学参数。结果氟虫腈的毒动学参数:k10为(2.08±0.83)h-1,k12为(0.34±0.07)h-1,k21为(0.27±0.05)h-1,cmax为(3.48±0.52)m.gL-1;t1/2α为(0.31±0.11)h;t1/2β为(3.25±0.59)h;AUC为(4.96±1.22)mg.h.L-1;C l为(1.49±0.44)L.h-1;V1为(0.67±0.15)L.kg-1;V为(2.62±0.65)L.kg-1;砜化物的毒动学参数:cmax为(1.10±0.10)m.gL-1;tmax为(6.08±1.94)h;t1/2ke为(81.3±4.8)h;AUC为(136±16)mg.h.L-1;C l为(0.05±0.005)L.h-1;Vd为(2.32±0.11)L.kg-1。结论氟虫腈静脉给药的毒物代谢动力学符合二室模型;其砜化物的毒物代谢动力学符合一室模型。氟虫腈砜化物的半衰期明显长于氟虫腈。     

Unintentional insecticide poisoning by age: an analysis of Queensland Poisons Information Centre calls

Objective: Data from the Queensland Poisons Information Centre (QPIC) was assessed to determine mechanisms of acute insecticide poisoning in young children (<5 years) and whether age affects insecticide‐poisoning patterns. Methods: Records of all insecticide‐related calls placed to QPIC in 2014 were obtained. A stratified analysis of call patterns by age was conducted. Results: Of 743 insecticide‐related calls received by QPIC 364 (49.0%) were for young children. The number of calls peaked in children aged one. Ant and cockroach baits accounted for 39.0% of calls. Sprays, which were found to contain not only pyrethroids, pyrethrins and/or piperonly butoxide but also the organophosphate diazinon, accounted for 25.8% of calls. Mouthing or ingesting a pest‐control product and consuming an item/insect after treatment were common mechanisms for children under the age of two. Topical exposure to sprays, via direct application, typically by the child or an older sibling, peaked in children aged two. In 12.3% of calls medical attention for the child was already sought or advised by QPIC. Conclusion: Normal behaviours associated with child development, particularly mouthing behaviours, explained the peak of exposure in one‐year‐olds. This finding should guide strategies to minimise poisonings in this vulnerable population.     

Meloxicam inhibits fipronil‐induced apoptosis via modulation of the oxidative stress and inflammatory response in SH‐SY5Y cells

Oxidative stress and inflammatory responses have been identified as key elements of neuronal cell apoptosis. In this study, we investigated the mechanisms by which inflammatory responses contribute to apoptosis in human neuroblastoma SH‐SY5Y cells treated with fipronil (FPN). Based on the cytotoxic mechanism of FPN, we examined the neuroprotective effects of meloxicam against FPN‐induced neuronal cell death. Treatment of SH‐SY5Y cells with FPN induced apoptosis via activation of caspase‐9 and ‐3, leading to nuclear condensation. In addition, FPN induced oxidative stress and increased expression of cyclooxygenase‐2 (COX‐2) and tumor necrosis factor‐α (TNF‐α) via inflammatory stimulation. Pretreatment of cells with meloxicam enhanced the viability of FPN‐exposed cells through attenuation of oxidative stress and inflammatory response. FPN activated mitogen activated protein kinase (MAPK) and inhibitors of MAPK abolished FPN‐induced COX‐2 expression. Meloxicam also attenuated FPN‐induced cell death by reducing MAPK‐mediated pro‐inflammatory factors. Furthermore, we observed both nuclear accumulation of p53 and enhanced levels of cytosolic p53 in a concentration‐dependent manner after FPN treatment. Pretreatment of cells with meloxicam blocked the translocation of p53 from the cytosol to the nucleus. Together, these data suggest that meloxicam may exert anti‐apoptotic effects against FPN‐induced cytotoxicity by both attenuating oxidative stress and inhibiting the inflammatory cascade via inactivation of MAPK and p53 signaling. Copyright © 2015 John Wiley & Sons, Ltd.     

Fipronil interferes with the differentiation of mouse N2a neuroblastoma cells

The purpose of this study was to evaluate the neurotoxic potential of the pesticide fipronil (FIP) towards the differentiation of mouse N2a neuroblastoma cells. At concentrations of 1, 5 and 10 μM that were not cytotoxic, as shown by two different cell viability assays, FIP impaired potently after 24 h the development of axon-like processes, with a concentration of 1 μM causing 50% inhibition. Densitometric analysis of immunoblots of extracts of N2a cells exposed to FIP demonstrated that the axon-inhibitory action of the pesticide was not accompanied by significant changes in the levels of total and phosphorylated neurofilament heavy chain (NFH). FIP also induced no alteration in the levels of total and tyrosinated α-tubulin. On the other hand, this pesticide caused severe disruption of the developmentally important ERK 1/2-MAP kinase signal transduction pathway, as evidenced by significant reductions in the activation state of MAPK kinase (MEK 1/2) and, particularly, ERK 1/2. The above data seem to justify very recent concerns that FIP has the capacity to induce developmental neurotoxicity in mammals.     

新型灭蟑毒饵的研究

目的 :为研究新型灭蟑毒饵对蟑螂的杀灭作用。方法 :采用四臂嗅觉仪从多种供试材料中筛选含有对德国小蠊有引诱作用的材料 ,并用这种材料与几种杀虫剂配成不同毒饵。结果 :动物饲料Ⅰ号对德国小蠊具有明显的引诱作用 ,且可以与其它不同杀虫剂混配 ,0 1%锐劲特混配毒饵对德国小蠊 4 8h死亡率可达10 0 % ,LD50 为 80 6 8± 2 5 1。结论 :0 1%锐劲特毒饵有很强的引诱毒杀作用 ,且群体杀灭较彻底 ,不易反弹     

白蚁防治后香榧中氟虫腈残留量的检测

目的使用白蚁诱杀盒(含氟虫腈)防治香榧树白蚁后,检测氟虫腈在香榧中的残留量。方法利用气相色谱法对香榧样品中的氟虫腈残留量进行检测。结果氟虫腈及其3种代谢物在香榧中的平均添加回收率在66.5%～115.8%之间,相对标准差介于2.2%～15.6%之间,符合农药残留分析要求。而香榧样品中氟虫腈残留量检出浓度低于0.001 mg/kg。结论使用诱杀盒防治白蚁后,香榧果实无毒、无氟虫腈残留,符合环保要求。     

Interaction between Short-Term Heat Pretreatment and Fipronil on 2nd Instar Larvae of Diamondback Moth, Plutella Xylostella (Linn)

Based on the cooperative virulence index (c.f.) and LC₅₀ of fipronil, the interaction effect between short-term heat pretreatment and fipronil on 2^nd instar larvae of diamondback moth (DBM), Plutella xylostella (Linnaeus), was assessed. The results suggested that pretreatment of the tested insects at 30 °C for 2, 4 and 8h could somewhat decrease the toxicity of fipronil at all set concentrations. The LC₅₀ values of fipronil increased after heat pretreatment and c.f. values in all these treatments were below zero. These results indicated that real mortalities were less than theoretical ones and antagonism was found in the treatments of fipronil at 0.39 and 0.78 mg/L after heat pretreatment at 30 °C at 2, 4 and 8 h. However, pretreatment at 30 °C for 12h could increase the toxicity of fipronil at all set concentrations, the LC₅₀ of fipronil decreased after heat pretreatment and c.f. values in all these treatments were above zero, which indicated real mortalities were higher than theoretical ones. Pretreatment of the tested insects at 35 °C for 2, 4, 8 and 12h was found to increase the toxicity of fipronil at all set concentrations which resulted in the decrease of LC₅₀ values of fipronil and c.f. above zero in all treatments with only one exception. Most interactions were assessed as synergism. The results indicated that cooperative virulence index (c.f.) may be adopted in hormetic effect assessment.