敌枯双慢性毒性实验的病理形态学研究——实验大鼠脏器组织病理变化

将150只SD大鼠随机地分成Ⅰ,Ⅱ,Ⅲ,Ⅳ四个实验组和一个对照组(Ⅴ)。实验组敌枯双剂量分别为1.0,0.2,0.05及0.01mg/kg,均用去离子水配成相应浓度的染毒水,由动物自由摄取,对照组摄入去离子水。于实验第29.5,55周分两批处死。经组织病理学检查,结果发现:敌枯双可引起甲状腺滤泡上皮细胞萎缩甚至脱屑,其发生率(Ⅲ组为63.64%)与对照组(0%)比较差异有高度显著性(P<0.01);睾丸曲细精管各级生精细胞减少、萎缩甚至完全消失,其发生率(Ⅳ组为58.33%)与对照组(8.33%)比较差异有显著性(P<0.01);对心肌、肝组织也有不同程度的损伤.     

A review of the effect of pesticide formulations on male fertility

Experimental studies suggest that large numbers of chemicals, environmental and industrial pollutants affect the male reproductive system. At present, almost no information is available on the effects of these adverse agents on human reproduction. Recent reports, however, suggest that in the past 50 years male fertility has declined based on qualitative and quantitative measurements of normal sperm. This study identifies‐among the active ingredients and solvents included in pesticide formulations registered in Italy‐the chemical agents with experimental evidence of male reproductive toxicity. Documents produced by international agencies and organizations such as IARC, EPA, WHO, and original papers from the international literature were systematically reviewed. The results indicate that several pesticide products notified in the Italian Registry contain active ingredients and/or solvents severely affecting testicular function and sperm morphology in laboratory animals. Therefore, exposure to reproductive toxicants occurring among manufacturers and users of pesticide formulations registered in Italy suggest further epidemiologic surveys should be conducted in this area.     

低剂量混配农药对家兔血浆谷胱甘肽过氧化物酶和一氧化氮的影响

目的 探讨低剂量混配农药对家兔脂质过氧化及一氧化氮（NO）浓度的影响及意义。方法 将家兔随机分为6个混配农药染毒组、1个丙溴磷染毒组和1个对照组，于不同的时间测定各组血清胆碱酯酶（ChE)活力、谷胱甘肽过氧化物酶（GSH-Px)活力及一氧化氮（NO）浓度。结果 除较高剂量混配农药组外，其余各组染毒后的ChE活力均大于对照组实验前平均值的70%。随着染毒时间的延长农药混配组血浆GSH-Px活力高于或显著高于同时间的单剂量组和对照组，而血浆NO的浓度则呈降低趋势。结论 低剂量含有机磷的混配农药在导致ChE活力降低之前即可造成脂质过氧化增强和NO浓度的降低。     

气相色谱-串联质谱法结合QuEChERS法快速检测中药中50种农药残留

目的 建立运用气相色谱-串联质谱（GC-MS/MS）法快速筛查460份中药材及其中药饮片（43份）中常用的50种农药残留。方法 通过对比《中国药典》2020版中药中农药残留的前处理方法,优选中药中50种农药残留的适配性前处理方法。中药样品经乙腈溶剂提取,以Qu ECh ERS法处理,采用GC-MS/MS测定,内标法定量。结果 在460份检测样品中共检出农药残留66份,总检出率为14.3%,检出禁用农药6份,检出率为1.3%,43份中药饮片中农药残留检出率为11.6%,未检出禁用农药。农残的检出是季节性分布集中出现在第3、4季度,农贸市场和种植地的农残检出率明显高于医院和药店,并且存在农残超标情况。中药中根类和叶类受污染最重,中药材全草类中农药残留最多,检出率为20.4%,其次为叶类18.3%和根茎类16.3%,中药饮片中农残最高为叶类,检出率为15.4%,全草类检出率为11.1%、根茎类检出率为6.2%,全草类、根茎类和叶类存在样品中检出多种农药残留的现象。结论 该方法简单快速、灵敏度高、重现性好、准确度高,可快速筛查中药中农药残留,为保障中药质量提供参考。     

UV filters with antagonistic action at androgen receptors in the MDA-kb2 cell transcriptional-activation assay.

The fact that certain ultraviolet (UV) filters used in cosmetics display estrogenic activity prompted us to study potential actions on androgen receptors (AR) in the human breast carcinoma cell line MDA-kb2, which expresses functional endogenous AR and glucocorticoid receptors (GR) and is stably transfected with a luciferase reporter plasmid. Dihydrotestosterone (DHT), methyltrienolone (R1881), methyltestosterone, danazol, and androstenedione increased luciferase activity, with EC50 values between 0.11 nM (R1881), 0.14 nM (DHT), and 73.5 nM (androstenedione). DHT-induced luciferase gene expression was inhibited by nonsteroidal antiandrogens, hydroxyflutamide, flutamide, bicalutamide, and vinclozolin. In contrast, the steroidal AR agonist/antagonist cyproterone actetate showed agonistic activity in the absence and presence of DHT, which was not blocked by hydroxyflutamide and thus seems not to be mediated by AR. GR-mediated activation of luciferase by dexamethasone was 100 times less potent than DHT and was not antagonized by hydroxyflutamide. The cell line was used for screening of UV filters, benzophenone-3 (Bp-3), benzophenone-4, 3-benzylidene camphor, 4-methylbenzylidene camphor, butyl-methoxy-dibenzoylmethane, homosalate (HMS), octyl-dimethyl-PABA, and octyl-methoxycinnamate. Two of these, Bp-3 and HMS, antagonized DHT-induced AR activation below cytotoxic concentrations, with IC50 of 5.57 10-6 M (HMS) and 4.98 10-6 M (Bp-3). None of the eight UV filters displayed agonistic activity when tested alone, but high concentrations of Bp-3 induced an increase of luciferase activity in the presence of dexamethasone, which was not blocked by hydroxyflutamide or the estrogen antagonist, ICI 182,780. These data indicate that the UV filters Bp-3 and HMS possess antiandrogenic activity in vitro in addition to estrogenic activity.     

经食道心脏起搏在救治口服有机磷农药中毒心跳骤停中的应用体会

目的探讨口服有机磷中毒患者心跳骤停时应用食道心脏调搏进行救治的疗效。方法15例心脏骤停患者,在常规治疗基础上应用食道心脏调搏方法抢救。结果15例中救治成功13例。结论经食道心脏起搏方法简便、操作速度快、无创、无需消毒、效果良好,适用于临床紧急起搏,尤其适用于基层医院。     

Immunotoxic effects of short-term atrazine exposure in young male C57BL/6 mice.

The herbicide atrazine (ATR) is a very widely used pesticide; yet the immunotoxicological potential of ATR has not been studied extensively. Our objective was to examine the effect of ATR on selected immune parameters in juvenile mice. ATR (up to 250 mg/kg) was administered by oral gavage for 14 days to one-month-old male C57BL/6 mice. One day, one week, and seven weeks after the last ATR dose, mice were sacrificed, and blood, spleens, and thymuses were collected and processed for cell counting and flow cytometry. Thymus and spleen weights were decreased by ATR, with the thymus being more sensitive than the spleen; this effect was still present at seven days, but not at seven weeks after the last ATR dose. Similarly, organ cellularity was persistently decreased in the thymus and in the spleen, with the splenic, but not thymic cellularity still being depressed at seven weeks post ATR. Peripheral blood leukocyte counts were not affected by ATR. There were also alterations in the cell phenotypes in that ATR exposure decreased all phenotypes in the thymus, with the number of CD4(+)/CD8(+) being affected the least. At the higher doses, the decreases in the thymic T-cell populations were still present one week after the last ATR dose. In the spleen, the CD8(+) were increased and MHC-II(+) and CD19(+) cells were decreased one day after the last ATR dose. Also, ATR treatment decreased the number of splenic na?ve T helper and T cytotoxic cells, whereas it increased the percentage of highly activated cytotoxic/memory T cells. Interestingly, the proportion of mature splenic dendritic cells (DC; CD11c(high)), was also decreased and it persisted for at least one week, suggesting that ATR inhibited DC maturation. In the circulation, ATR exposure decreased CD4(+) lymphocytes at one day, whereas at seven days after the last ATR dose, in addition to the decrease in CD4(+) lymphocytes, the MHC-II(+) cells were also decreased at the 250 mg/kg dose. Thus, ATR exposure appears to be detrimental to the immune system of juvenile mice by decreasing cellularity and affecting lymphocyte distribution, with certain effects persisting long after exposure has been terminated.     

Increasing crop field size does not consistently exacerbate insect pest problems

Increasing diversity on farms can enhance many key ecosystem services to and from agriculture, and natural control of arthropod pests is often presumed to be among them. The expectation that increasing the size of monocultural crop plantings exacerbates the impact of pests is common throughout the agroecological literature. However, the theoretical basis for this expectation is uncertain; mechanistic mathematical models suggest instead that increasing field size can have positive, negative, neutral, or even nonlinear effects on arthropod pest densities. Here, we report a broad survey of crop field-size effects: across 14 pest species, 5 crops, and 20,000 field years of observations, we quantify the impact of field size on pest densities, pesticide applications, and crop yield. We find no evidence that larger fields cause consistently worse pest impacts. The most common outcome (9 of 14 species) was for pest severity to be independent of field size; larger fields resulted in less severe pest problems for four species, and only one species exhibited the expected trend of larger fields worsening pest severity. Importantly, pest responses to field size strongly correlated with their responses to the fraction of the surrounding landscape planted to the focal crop, suggesting that shared ecological processes produce parallel responses to crop simplification across spatial scales. We conclude that the idea that larger field sizes consistently disrupt natural pest control services is without foundation in either the theoretical or empirical record.

Agroecology suggests that augmenting the diversity of plant communities in working landscapes can enhance biodiversity and a variety of important ecosystem services, including pollination and natural pest control (1–17). The effects of plant diversity are thought to operate across spatial scales. Within a single field, agroecologists have shown that polycultures, mixtures of different crop species grown within a single field, will often enhance the suppression of pest populations (2, 18). At the single-field scale, agroecologists have warned that increasing the spatial extent of single monocultural crops, a consistent feature of the increasing industrialization of farming (3, 14, 19, 20), will worsen pest problems (2, 4, 10, 11, 17, 21). Field size has thus become a proxy for diverse and sustainable production. And finally, at the landscape level, agroecologists have promoted the retention of natural habitat patches, the cultivation of a greater diversity of crop plant species, and the design of landscapes with greater edge densities (2, 4, 7, 9–12, 15, 16).The prediction that larger monocultural fields exacerbate pest problems has a somewhat murky origin (22). Most authors seem to refer this expectation to the general idea that concentrating host plant resources either facilitates their exploitation by specialist herbivores (the resource concentration hypothesis; (23)) or impedes the effective action of natural enemies, which may require a diversity of plants to overwinter or acquire alternate prey, nectar, or pollen (the natural enemies hypothesis; 2, 4, 9, 21, 23). Nonetheless, formal mathematical and simulation models that examine the relationship between crop field size and pest dynamics after explicitly incorporating movement processes, overwintering, and predator-prey interactions do not support the expectation that increasing field size will consistently worsen pest problems. Instead, a variety of outcomes is predicted, with larger fields causing pest populations to either increase, decrease, show no response, or exhibit nonlinear dome- or U-shaped responses (22, 24–27).An extensive experimental literature has established that larger plant patches can have a variety of effects on herbivore densities, with negative and neutral relationships observed as often as positive relationships (9, 24–26, 28–30). But it is unclear whether these experiments, performed only at the very small spatial scales that are tractable for experimentalists, are relevant to the much-larger spatial scales of production agriculture (31). Larger-scale observational studies of patch size effects on herbivores have been reported in natural ecosystems (e.g., 28, 32–35). However, it is again hard to extend these results to agricultural systems, where frequent strong disturbances (e.g., pesticide applications, plowing, and replanting) are likely to amplify the importance of colonization processes relative to in situ birth and death processes.Surprisingly, direct empirical studies of the effect of commercial agricultural field size on pest pressure are rare. A recent elegant study by Gagic et al. (36) in Australian cotton fields confirmed the conventional wisdom that larger fields are associated with higher pest densities, increased pesticide use, and depressed crop yield. However, three other studies in Swedish willow plantations, Israeli citrus groves, and Canadian soybean fields instead found either no effect of larger fields on pest densities (37, 38) or a negative effect on pest densities (39) and a positive effect on predator densities (37).Several studies have also attempted to understand relationships between pests and field size by examining pesticide applications, seemingly confirming the agroecological expectation that more pesticides would be applied on larger fields (10, 11). However, this finding may result from field size shaping pest populations or from field size changing the cost-benefit calculus of pesticide use, independent of pest population densities. Indeed, heavier use of pesticides on larger fields may be favored by reduced per-hectare costs of pesticide applications (economies of scale) or because mobile pests represent a “public bad” that can be managed more effectively by individual farmers on a single-field basis if fields are larger and the speed of pest recolonization from adjacent properties is slowed (40). Because an effect of field size on pest pressure could be registered either by changes in observed pest densities or by changes in pesticide use (5, 41), data on pesticide use are most readily understood when combined with data on underlying pest densities. Patterns of pesticide use are also important in their own right, as pesticide applications are an immediate cost for farmers and a key externality of agricultural production (42).Ultimately, what many view as a core paradigm in agroecology, namely that larger monocultural crop fields worsen the impact of pests, appears to lack clear theoretical or empirical support. To address the paucity of empirical evidence, we compiled several large observational datasets of pest abundances, pesticide applications, and crop yields from commercial agriculture. Together, our datasets encompassed more than 20,000 field years of observations of 14 pest and 1 natural enemy species across both annual and perennial agroecosystems in the United States (cotton and citrus), Peru (potatoes), and Spain (grapes and olives). The pest taxa studied include, for each crop, the arthropod species that generate the greatest economic damage (43–48). Field sizes varied widely both between and within each of the studied cropping systems. Specifically, systems included subsistence farming conducted in very small fields (in Peru, potatoes: median field size = 360 m², range: 50–1,430 m²), agriculture being performed at an intermediate level of intensification (in Spain, grapes: median field size = 41,700 m², range: 600–242.78 × 10⁴ m²; olives: median field size = 62,700 m², range: 50–2.22 × 10⁷ m²), and highly industrialized farming (in California, citrus: median field size = 83,400 m², range: 2,020–57.53 × 10⁴ m²; cotton: median field size = 40.47 × 10⁴ m², range: 4,100–239.98 × 10⁴ m²).Our datasets also include information on field size and the amounts of the focal crop and, for four of the five datasets, natural habitat remnants in the broader landscape. To separate the effects of field size from other potentially correlated aspects of agricultural intensification, we included the identity of the farm (RanchID) or the pest control advisor who had responsibility for pest monitoring and control decisions (TechnicianID) in our statistical models. Finally, our dataset did not include information on smaller landscape elements, such as cover crops, insectary plantings, or hedgerows that are often specifically designed to enhance natural pest control. Thus, our analyses do not address the potential efficacy of these landscape elements.We addressed four questions. First, is the classical expectation for a positive relationship between field size and pest density consistently supported or, instead, are a variety of outcomes (positive, negative, neutral, and nonlinear) observed? Second, how do pesticide application frequencies change as field sizes increase? Third, are crop yields also sensitive to changes in field size? Crop productivity is of central importance both for the agricultural economy and for global food security (4, 5, 9, 42). Fourth, and finally, is there a correlation between pest responses to field size and their responses to amount of the same crop species in the broader, surrounding landscape? Agricultural landscape theory and crop-patch size theory have largely been developed separately; a finding of parallel influences would suggest that common ecological processes may be operating across spatial scales.     

大黄治疗重度有机磷农药中毒后多器官功能障碍综合征的临床研究

目的 研究大黄在防治重度急性有机磷中毒（AOPP）引起全身炎症反应综合征（SRIS）、胃肠功能障碍、多器官功能障碍综合征（MODS）方面的效果.方法 将100例受试对象按照随机对照原则分为大黄组50例和甘露醇组50例.2组均采用留置胃管反复洗胃,长托宁、氯解磷定肌注,综合对症治疗.在此基础上,大黄组予生大黄粉12.0g胃管注入,每8h 1次;甘露醇组予甘露醇250mL胃管注入,每12h 1次.均连续使用5d.统计2组患者入院时及病程的1,2,3,4,5d处于胃肠功能障碍、MODS状态的病例数以及血C反应蛋白（CRP）的浓度.结果 在病程的2,3,4,5d,大黄组血CRP浓度的降幅较甘露醇组显著（P均〈0.05）;胃肠功能障碍的改善快于甘露醇组,在病程的1,2,3d 2组比较有显著性差异（P均〈0.05）;第2,3,4,5天,大黄组MODS发生例数减少速度快于甘露醇组（P均〈0.05）.结论 大黄治疗AOPP患者能促进胃肠功能恢复,抑制CRP的释放,提升MODS防治效果.     

盐酸戊乙奎醚对急性有机磷中毒的疗效分析

目的比较盐酸戊乙奎醚与阿托品对救治急性有机磷农药中毒(AOPP)的疗效。方法选择我院2003年5月~2004年12月收治的57例救治成功的AOPP患者,其中使用盐酸戊乙奎醚治疗23例,用阿托品治疗34例,比较两组的临床疗效。结果两组患者在用药剂量、用药次数、住院天数和不良反应方面存在明显差异(P<0.01)。结论盐酸戊乙奎醚在多方面均明显优于阿托品,在AOPP的救治中可取代阿托品。