7种杀虫剂对北京地区烟粉虱成虫毒力的比较研究

本试验比较测定了7种杀虫剂对北京地区烟粉虱成虫的毒力,以期为北京地区高毒农药淘汰提供参考。结果表明:氟虫腈对烟粉虱成虫的毒力最强,其LC50值为2.98(g/mL;新烟碱类杀虫剂啶虫脒、吡虫啉对烟粉虱成虫的生物活性较好,LC50值分别为8.04(g/mL、7.49(g/mL,噻虫嗪对烟粉虱成虫毒力相对较差,LC50值仅为95.03(g/mL;烟粉虱成虫对马拉硫磷、异丙威和噻嗪酮3种杀虫剂不敏感。在北京地区,采用噻虫嗪、马拉硫磷、异丙威和噻嗪酮等杀虫剂,不能有效防治烟粉虱的成虫;氟虫腈、吡虫啉和啶虫脒可以用来防治烟粉虱成虫。     

Silicon mediates changes to some physiological and enzymatic parameters symptomatic for oxidative stress in spinach (Spinacia oleracea L.) grown under B toxicity

The effect of exogenous silicon (Si) on the growth, boron (B) uptake, stomatal conductance, lipid peroxidation (MDA), membrane permeability, lipoxygenase activity (LOX), proline and H₂O₂ accumulation, non-enzymatic antioxidant activity (AA) and the activities of major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT and ascorbate peroxidase, APX) of spinach were investigated under greenhouse conditions. Spinach plants were grown with 0 or 30 mg kg⁻¹ B combined with 0 and 150 mg kg⁻¹ Si. The severity of leaf symptoms of B toxicity was lower when the plants were grown with 150 mg kg⁻¹ Si. Silicon supplied to the soil with high B counteracted the deleterious effects of B on root and shoot growth. Application of B significantly increased B concentration in shoot and in root tissues. However, Si decreased B concentration in the shoots but increased it in the roots. Shoot tissues of spinach contained higher B than the roots in all treatments. Applied Si increased the Si concentration of the root and shoot. Stomatal conductance of the plants was decreased by B, but was increased by Si. The concentrations of H₂O₂ and proline were increased by B toxicity but were decreased by Si applied to plants. Boron toxicity increased the membrane permeability, MDA content and LOX activity of excised leaves of spinach. Applied Si ameliorated the membrane deterioration significantly. Compared with control plants, the activities of AA, SOD, CAT and APX in B-stressed plants without Si applied increased, and application of Si decreased their activities under toxic B conditions. Based on the present work, it can be concluded that Si alleviates B toxicity by preventing oxidative membrane damage and also translocation of B from root to shoots. To our knowledge, this is the first report on the effect of Si in improving B tolerance in spinach.     

小鼠和大鼠口服氢溴酸槟榔碱的急性毒性试验

研究口服氢溴酸槟榔碱对小鼠和大鼠的急性毒性,为将其研究开发为新药奠定基础,为临床用量的确定提供科学依据.选用昆明种小鼠及SD大鼠,经口灌胃一次给药,统计死亡率,用改良寇氏法计算半数致死量(LD50),并观察毒性作用.结果氢溴酸槟榔碱对小鼠的口服LD50为691.83 mg/kg,95%可信区间为642.92 mg/kg～744.47 mg/kg;对SD大鼠的口服LD50为2 054 mg/kg,95%可信区间为1 908 mg/kg～2 210 mg/kg.表明氢溴酸槟榔碱属于低毒性的药物,按1 mg/kg～5 mg/kg临床应用非常安全.     

实验性天府肉鹅锌中毒症的病理学观察

1日龄天府肉鹅健雏200只,随机分为4组,分别喂以:(1)基础日粮(Zn 100mg/kg日粮,对照组)、(2)基础日粮 Zn 900mg/kg、(3)基础日粮 Zn 1400mg/kg、(4)基础日粮 Zn 1900mg/kg,试验期7周,进行系统的病理学观察.中毒组雏鹅出现生长迟缓、拉稀、跛行等临床症状.组织学观察,肝细胞颗粒变性,骨骼肌及肌胃平滑肌变性坏死,胸腺、腔上囊和脾脏淋巴细胞数量减少、变性、坏死.血液病理学变化,主要是血清碱性磷酸酶活性下降,骨/肝碱性磷酸酶比值升高,谷丙转氨酶、肌酸激酶及淀粉酶活性程度不同地升高,血清胰岛素含量升高,仅基础日粮 Zn 1900mg/kg组49日龄降低.结果表明,高锌对鹅可产生明显的毒害作用.     

豆类丝核菌次级代谢产物的急性毒性与致突变性试验

通过经口急性毒性试验、小鼠骨髓微核试验和精子畸形试验对豆类丝核菌次级代谢产物的急性毒性和致突变性进行了研究.结果表明,以该代谢产物中苦马豆素的量计算,小鼠经口急性毒性试验的LD50为226.46mg/kg,LD50的95%可信限为158.49～323.59mg/kg,是治疗肿瘤剂量的14～84倍,属于实际低毒级药物.微核试验和精子畸形试验的各试验组与阴性对照组比较差异均不显著(P＞0.05),说明豆类丝核菌次级代谢产物无明显致突变性;各试验组之间比较差异均不显著(P＞0.05),说明微核的形成和精子畸形的形成与受试物无量效关系.结论:豆类丝核菌次级代谢产物是一种较安全的抗肿瘤药物.     

黄瓜根边缘细胞生物学特性及其对铝的响应

 以黄瓜为试验材料, 研究了黄瓜根边缘细胞的生物学特性及其对铝毒的响应。试验结果表明,在黄瓜种子萌发过程中, 根边缘细胞有很高的活性。当根长度在25 mm, 根边缘细胞数目达到最高值5 480个, 根伸长到10 mm时, PME (果胶甲基酯酶) 相对活性达到最高值, 然后随着根的伸长, PME相对活性逐渐下降。在铝处理的条件下, 黄瓜根长及边缘细胞的存活率会随着铝液浓度的升高依次递减, 说明铝毒对根的发育有明显的抑制作用及危害, 而根冠的PME活性却有所提高, 说明了PME与植物铝毒胁迫之间存在着相关性。铝毒条件下边缘细胞PME活性的提高, 使细胞壁的果胶去甲基化, 增加了Al³⁺的结合位点, 从而避免铝更多地进入细胞内, 造成对植物的毒害。     

复方中药透皮软膏剂的药理与毒理作用研究

目的：研究复方中药透皮软膏剂的药理学与毒理学作用.方法：将蒲公英、金银花、连翘、赤芍、黄芩等9味中药组成复方,以水提醇沉法制得干浸膏,再与油相、水相与促渗剂制成O/W型透皮软膏剂,采用局部全封闭斑贴法进行皮肤刺激试验与皮肤致敏试验.将干浸膏加纯水稀释含生药量分别为5g/ml和1g/ml两种浓度的提取液,前者供急性毒性试验用,选用昆明系小白鼠,经口染毒后,观察7 d,用K（a）rber法计算LD50;后者用G3垂熔玻璃漏斗过滤,流通蒸气灭菌20 min,供抗菌试验用,采用试管二倍稀释法,测定提取液体外对6种病原菌的抗菌活性.结果：皮肤刺激平均分值小于0.5,为无刺激物;致敏率为0,属于弱致敏物;对金黄色葡萄球菌、大肠杆菌、无乳链球菌、停乳链球菌、牛棒状杆菌、革兰氏阴性小杆菌的MIC分别为31.3、62.5、62.5、62.5、125、125 g/l,MBC分别为62.5、125、62.5、62.5、125、125g/l;小鼠口服LD50为l0 140 g/kg,LD50 95%可信限为8 610～11 940 g/kg,属于实际无毒物质.结论：该方剂提取液具有较强的体外抗菌活性,可作为替代抗生素防治奶牛乳房炎的主药,研制开发的透皮软膏剂用于乳房炎局部治疗安全无毒.     

转化型人参皂甙的生物活性:体外实验研究

将人参总皂甙经化学转化成转化型人参皂甙后分离得8个组分，在体外细胞上进行了转化型人参皂甙8个组分对CEF细胞毒性、生长活性、诱导肿瘤细胞凋亡、诱导单克隆抗体生成以及抗IBDV、AIV（H9）、NDV、MDV病毒的活性研究。结果发现，转化型人参皂甙各组分的细胞毒性作用在23．26～39．53mg／L之间；对鸡胚成纤维细胞（CEF）的生长和活性呈促进作用的工作浓度在10～20mg／L之间；转化型人参皂甙8号组分12．5mg／L诱导48h后，肝癌细胞7402株有60％的细胞凋亡，大鼠脑胶质瘤细胞C6株有35％的细胞凋亡；3、4、7号组分12．5mg／L和6．25mg／L对单克隆抗体6E6株杂交瘤细胞和单克隆抗体10B11株杂交瘤细胞的单抗生成具有明显促进作用，其HI效价为2^6～7与对照组的2^5相比有明显差异，IFA效价为10^4～5与对照组的10^2相比有极显著差异；4、7、8号组分15mg／L阻斯IBDV、AIV（H9）、NDV感染CEF细胞的作用都达到了51．1％以上，抑制IBDV、AIV（H9）、NDV在CEF上增殖的作用都在30％以上；6、7号组分12．5mg／L在阻断感染、抑制增殖、直接杀灭3种方式的抗MDV—RB1B强毒株在SPF鸡CEF细胞上的空斑减数率都达了到ACV抗MDV空斑减数率的80％，其中4、6号组分对MDV—RBIB株的直接杀灭作用与ACV的杀灭作用相等。表明人参总皂甙经化学处理转变成转化型人参皂甙，可明显改变其生物学活性。     

蛋氨酸对北京鸭的毒性研究

本试验采用单因子完全随机设计,144只21日龄北京鸭随机分为3组。1组为对照组,饲喂基础日粮,2组、3组为基础日粮中添加1%、2%DL-蛋氨酸(DL-Met),研究过量蛋氨酸对北京鸭的影响。试验结果表明:添加1%、2%蛋氨酸降低采食量和日增重(P<0.05);添加2%蛋氨酸组料肉比升高(P<0.05);2%蛋氨酸组血浆中白蛋白(Alb)含量降低(P<0.05),谷丙转氨酶(ALT)、谷草转氨酶(AST)、乳酸脱氢酶(LDH)的含量增加(P<0.05),表明对肝细胞造成损伤,产生了毒性作用。     

Comparison of unilateral versus bilateral nasal catheters for oxygen administration in dogs

Objective: To determine the effect of bilateral nasal oxygen supplementation on tracheal airway and arterial blood gas parameters. Design: Original research. Setting: Research Laboratory. Animals: Eight normal dogs. Interventions: None. Measurements: Intra‐tracheal oxygen concentration and arterial oxygen partial pressure at three different oxygen flow rates given through either unilateral or bilateral nasal catheters. Main results: F_IO₂ and PaO₂ were significantly increased with higher total oxygen flow rates, but the increase was the same whether the higher flow was delivered through one nasal catheter or divided and administered though two nasal catheters. The use of bilateral nasal catheters allowed a tracheal F_IO₂ as high as 0.60 with minimal patient discomfort. Conclusions: The benefit of bilateral nasal catheters for oxygen supplementation is the ability to provide high total oxygen flows with decreased risk of patient discomfort. If the desired oxygen flow can be achieved with a unilateral nasal catheter, then the only benefit of bilateral catheters is increased patient comfort. The use of bilateral nasal oxygen catheters for oxygen supplementation can result in an F_IO₂ that is high enough to produce oxygen toxicity with prolonged administration.