瑞香狼毒素对菜粉蝶幼虫的杀虫活性

在本实验室前期工作中,发现生长于青藏高原的有毒植物瑞香狼毒对菜青虫具有较好的防治效果.采用微量点滴法研究瑞香狼毒素对菜青虫的触杀活性,以叶片夹毒法和灌喂法研究胃毒活性.在触杀活性试验中,72h的致死中量(LD50)为0.96μg/头,以6.25×103mg·L-1浓度的样品液2μL点滴试虫,即1.25×10μg/头处理组的72h校正死亡率为92.2%.在胃毒活性试验中,72h叶片夹毒法的致死中浓度(LC50)为3.82×103mg·L-1,5.00×104 mg·L-1浓度处理组校正死亡率为91.2%;72h灌喂法的LD50为3.80μg/头,以5.00×104mg·L-1浓度的样品液2μL灌喂试虫,即1.00×102μg/头的处理组的72h校正死亡率为96.8%.结果表明,瑞香狼毒素对菜青虫具有较好的触杀活性和一定的胃毒活性.     

甲霜灵、福美以及其复配对辣椒疫病菌的毒力测定

室内恒温条件下，采用孢子囊萌发抑制法测定了甲霜灵、福美双及其复配对辣椒疫病的毒力，用Horsfall的毒力试验设计和Wadley的增效比率法评价了2种杀菌剂的联合作用。结果表明，EC50剂量甲霜灵与福美双混用表现增效作用，其中70：30混剂配比的增效比率为3.18。接种试验也证明其对辣椒疫病具有较好的防治作用。     

Intermittent peritoneal dialysis for the treatment of acute renal failure in two horses

Acute renal failure (ARF) in the horse is most commonly due to decreased renal perfusion or a nephrotoxic insult. Conventional therapy includes the administration of i.v. fluids, frusemide, mannitol and/or dopamine, as well as general supportive care. However, not all horses with ARF will respond to these treatments. In these cases, peritoneal dialysis is a viable therapeutic option. This case report describes 2 horses with ARF that was refractory to conventional therapy. Intermittent peritoneal dialysis was used effectively in both cases for treatment of the ARF. Dialysis was easy to perform and associated only with minor complications. To the authors' knowledge, this is the first report describing the successful use of intermittent peritoneal dialysis in the treatment of ARF in the horse.     

Brunfelsia spp (yesterday, today, tomorrow) toxicity in four dogs

Four dogs were treated for acute toxicity following ingestion of the popular garden shrub 'Yesterday, today, tomorrow' (Brunfelsia spp). Clinical signs included vomiting, diarrhoea, muscle tremors, anxiousness, opisthotonus and seizures. All dogs recovered following treatment with any or all of general anaesthetic, gastric lavage, enema, diazepam, phenobarbitone or propofol sedation. Brunfelsia spp toxicity should be considered in young, previously healthy dogs presenting with gastrointestinal signs that rapidly progress to muscle tremors and seizures. Examination of faeces was required for diagnosis in all cases. Owners should also be questioned thoroughly about their dogs' access to such plants.     

恩诺沙星对隆腺蚤(Daphnia Carinata)的急性活动抑制毒性测定

恩诺沙星是在畜禽养殖业中得到广泛应用的抗菌药物。以隆腺蚤(DaphniaCarinata)为试验对象,测定了恩诺沙星对隆腺蚤的急性毒性。结果表明,25℃时,24h恩诺沙星对隆腺蚤的最大不致死浓度为1μg·mL-1,使隆腺蚤全部死亡的最低浓度为120μg·mL-1;恩诺沙星在24h、48h时对隆腺蚤的EC50分别为34.03μg·mL-1和19.37μg·mL-1。48h时,恩诺沙星对隆腺蚤的LC50为25.86μg·mL-1。依据蚤类急性活动抑制毒性分级标准,恩诺沙星对于隆腺蚤属于中毒性化合物。     

Absolute Structure Determination and Kv1.5 Ion Channel Inhibition Activities of New Debromoaplysiatoxin Analogues

Potassium channel Kv1.5 has been considered a key target for new treatments of atrial tachyarrhythmias, with few side effects. Four new debromoaplysiatoxin analogues with a 6/6/12 fused ring system were isolated from marine cyanobacterium Lyngbya sp. Their planar structures were elucidated by HRESIMS, 1D and 2D NMR. The absolute configuration of oscillatoxin J (1) was determined by single-crystal X-ray diffraction, and the absolute configurations of oscillatoxin K (2), oscillatoxin L (3) and oscillatoxin M (4) were confirmed on the basis of GIAO NMR shift calculation followed by DP4 analysis. The current study confirmed the absolute configuration of the pivotal chiral positions (7S, 9S, 10S, 11R, 12S, 15S, 29R and 30R) at traditional ATXs with 6/12/6 tricyclic ring system. Compound 1, 2 and 4 exhibited blocking activities against Kv1.5 with IC₅₀ values of 2.61 ± 0.91 µM, 3.86 ± 1.03 µM and 3.79 ± 1.01 µM, respectively. However, compound 3 exhibited a minimum effect on Kv1.5 at 10 µM. Furthermore, all of these new debromoaplysiatoxin analogs displayed no apparent activity in a brine shrimp toxicity assay.     

斜生四链藻对水中四环素的胁迫响应及去除作用

四环素由于其低生物降解性和水溶性而在水环境中持续存在,对生态环境安全造成较高的潜在风险。为探讨水环境中残留的四环素与藻类的相互作用,以斜生四链藻为研究对象,考察了斜生四链藻对水中不同浓度四环素(0.5、1.0、1.5、2.5、4.0和6.0 mg·L^-1)的胁迫响应及去除作用。结果表明,各浓度四环素处理组均对斜生四链藻的生长产生抑制作用,最高抑制率达到了72.99%,四环素对斜生四链藻的半数效应质量浓度(96 h-EC50)和抑制效应为80%质量浓度(96 h-EC80)分别为2.46和6.9 mg·L^-1。在相同浓度四环素胁迫下,斜生四链藻的光合色素含量和Fv/Fm值呈现出和斜生四链藻细胞密度变化相同的趋势,与对照组相比,6.0 mg·L^-1浓度处理组中斜生四链藻的叶绿素a、叶绿素b和类胡萝卜素含量在96 h的抑制率分别是87.32%、66.91%和87.58%,Fv/Fm值降幅达到了77.4%。在低、中、高浓度四环素(0.5、1.5和6.0 mg·L^-1)胁迫下暴露96 h,斜生四链藻的丙二醛(...     

Comparative hepatotoxicity of a herbicide,epyrifenacil, in humans and rodents by comparing the dynamics and kinetics of its causal metabolite

A new herbicide, epyrifenacil (S-3100), inhibits protoporphyrinogen oxidase (PPO) in plants. Repeated administration of epyrifenacil in laboratory animals led to some toxicological changes related to PPO inhibition, e.g., hepatotoxicity caused by porphyrin accumulation and anemia caused by the inhibition of heme biosynthesis. In vitro studies revealed that an ester-cleaved metabolite, S-3100-CA, is predominant in mammals, exhibits PPO-inhibitory activity, and thus is the cause of epyrifenacil-induced toxicity. To assess the human risk, the effects of species differences on the dynamics (PPO inhibition) and kinetics (liver uptake) of epyrifenacil were evaluated separately. The results of in vitro assays revealed an approximately tenfold weaker inhibition of PPO by S-3100-CA in humans than in rodents and six- to thirteen-fold less hepatic uptake of S-3100-CA in humans than in mice. Finally, it was suggested that humans are less sensitive to the toxicity of epyrifenacil than are rodents, although further mechanistic research is highly anticipated.     

六溴环十二烷(HBCD)和Cu2+单独与联合暴露对海水小球藻的毒性作用

为探究典型溴化阻燃剂六溴环十二烷(HBCD)和重金属Cu²⁺对海水小球藻(Chlorella salina)的毒性作用,本研究测定HBCD和Cu²⁺单独和联合暴露96 h后小球藻的细胞密度、Chla含量和叶绿素荧光的变化情况。结果表明:单独暴露下,HBCD处理组藻细胞密度与对照组相比显著下降,其中500μg·L^-1 HBCD处理组抑制率最高(32.99%),Chl a含量和Fv/Fm则与对照组无显著差异;Cu²⁺处理组中,96 h-EC₅₀分别为637μg·L^-1(细胞密度)和541μg·L^-1(Chl a含量),Chl a含量对Cu²⁺的敏感性高于细胞密度,海水小球藻的生长受到明显抑制且呈剂量-效应关系,1 260μg·L^-1和2 000μg·L^-1 Cu²⁺处理组中Fv/Fm分别显著降低24.24%和32.32%;HBCD和Cu^2+<...     

蜂毒素—死亡素重组抗菌肽的小鼠毒性试验

本试验旨在探索蜂毒素—死亡素重组抗菌肽（MT-W）对昆明小鼠的毒性影响。试验通过小鼠口服急性毒性试验和口服生物利用度试验,研究了MT-W对小鼠主要脏器的影响,并检测了血液中碱性磷酸酶、丙氨酸氨基转移酶、天冬氨酸氨基转移酶等生化指标,并对MT-W的体内吸收情况进行了检测。结果显示,MT-W在试验设定浓度下,对试验小鼠的体重、器官/体重比率没有显著影响,血液生化指标与对照组也无统计学差异;在按照50 mg/kg体重给实验小鼠灌服MT-W溶液后,在血浆中未检测到MT-W。研究表明,MT-W对小鼠没有明显毒副作用,MT-W在口服后未被有效吸收。