Changes in thyroid hormone levels and related gene expressions in embryo–larval zebrafish exposed to binary combinations of bifenthrin and acetochlor

Ecotoxicology - Bifenthrin (BF) and acetochlor (AT) are widely used as an insecticide and herbicide, respectively, which are introduced to the aquatic environment as a natural result. Although the...     

多巴胺对鱼藤酮诱导α-突触核蛋白聚集的促进作用

目的:探讨多巴胺能细胞内多巴胺在鱼藤酮诱导α-突触核蛋白聚集过程中的作用。方法:采用鱼藤酮(1μmol/L)处理PC12细胞,流式细胞术检测双氢罗丹明123荧光强度;Western印迹法检测胞质内α-突触核蛋白表达;免疫荧光法观察α-突触核蛋白聚集体。并采用多巴胺耗竭剂——利血平预处理3h,观察上述指标。结果:鱼藤酮处理24h后,PC12细胞内过氧化物水平显著升高,而利血平(1μmol/L和5μmol/L)预处理后,细胞内过氧化物水平较鱼藤酮组显著下降(P<0.05)。鱼藤酮处理后,α-突触核蛋白表达水平显著升高,胞质内可见α-突触核蛋白免疫阳性的聚集体形成;采用利血平预处理后,α-突触核蛋白表达水平较鱼藤酮组显著下降(P<0.05),α-突触核蛋白聚集体面积减小。结论:在鱼藤酮作用过程中,多巴胺可促进α-突触核蛋白表达上调及其聚集体的形成。     

山苦茶的抗菌和抗病毒作用研究

山苦茶的水蒸馏液成分对金黄色葡萄球菌和大肠埃希氏菌等六种试验菌无抗菌作用。但山苦茶的水提取液对大部分试验菌具有一定的抑菌效果。山苦茶干品的水提取液对金黄色葡萄球菌的抑菌效果最好,1:1水提液抑菌环直径为11 mm,最小抑菌浓度1:32;对福氏志贺氏菌的效果次之,抑菌环直径为11.5 mm,最小抑菌浓度为1:8;对铜绿色假单胞菌的抑菌效果最差,纸片法未见抑菌环,稀释法测得最小抑菌浓度为1:2。抗病毒作用研究用CPE法观察,对慢病毒Maedi病毒1011株无作用,而观察到在1:25的浓度时,对SYN羊二倍体细胞有细胞毒性作用。     

L-THP对脑缺血大鼠脑组织NO含量变化影响的研究

目的：通过检测局灶性脑缺血大鼠脑组织中ＮＯ含量的变化及左旋四氢巴马汀（Ｌ－ｔｅｔｒａｂｙｄｒｏｐａｌｍａｔｉｎｅ,Ｌ－ＴＨＰ）的影响．从而探讨Ｌ－ＴＨＰ的脑保护作用机制。方法：采用线栓法制备大鼠右侧大脑中动脉阻断（ＭＣＡＯ）模型。 应用硝酸还原酶法检测缺血３ｈ及４８ｈ脑组织 ＮＯ含量的变化及Ｌ－ＴＨＰ对ＮＯ含量的影响。结果：缺血３ｈ及４８ｈ脑组 织 ＮＯ含量明显升高,且４８ｈ缺血组ＮＯ含量高于３ｈ缺血组。缺血前３０ｍｉｎ应用Ｌ－ＴＨＰ２０ｍｇ／ｋｇ可明显降低３ｈ及 ４８ｈ脑缺血组织中ＮＯ含量。结论：Ｌ－ＴＨＰ可降低局灶性脑缺血脑组织中ＮＯ的含量。其脑保护作用是通过抑制ＮＯ介 导的神经毒性作用实现的。     

Analysis method development and health risk assessment of pesticide and heavy metal residues in Dendrobium Candidum

Herbal medicines that are widely used worldwide are easily contaminated by pesticides and heavy metals, threatening human health. In this study, a modified QuEChERS pre-treatment method combined with HPLC/GC-MS/MS was established for the determination of 24 pesticide residues in Dendrobium candidum. The average recoveries of 24 pesticides in D. candidum were 76.9–110.0% with the relative standard deviation (RSD) of 0.28–11.40%, and their limits of detection (LOD) and limits of quantitation (LOQ) were 0.005–10 and 0.011–22 μg kg⁻¹, respectively. The results showed that 83.33% of all samples had detected pesticide residues with the concentrations of 0.06–312.83 μg kg⁻¹. Meanwhile, microwave digestion combined with ICP-MS was used to detect the residues of 8 heavy metals in D. candidum. The average recoveries of 8 heavy metals were 82.7–108.1% with an RSD of 1.4–8.0%, and their LOD and LOQ were 0.0001–0.05 mg kg⁻¹ and 0.0003–0.2 mg kg⁻¹, respectively. The results indicated that 8 heavy metals were all detected in all samples, and the highest concentration of Zn was 11.97 mg kg⁻¹. Furthermore, the health risk assessment showed that the risk of the detected pesticides and heavy metals in samples to humans, specifically to the general population including adults and children, was acceptable.

Residues of 24 pesticides and 8 heavy metals in Dendrobium candidum were determinated using both the modified QuEChERS-HPLC(GC)-MS/MS and microwave digestion-ICP-MS analysis methods, and their health risk was acceptable.