猪α-干扰素在毕赤酵母中的分泌表达和下游工艺的研究

通过小量发酵、摇瓶发酵、大量发酵,研究猪α-IFN在毕赤酵母中表达的下游工艺,微量细胞板法测猪α-IFN体外抗VSV、PRRSV、TGEV的活性.猪α-IFN抗VSV的活性达到4.04×10~6IU/L,在PK15上抗TGEV的活性为10~7～10~8IU/L,在Mare 145上抗PRRSV的活性为10~6～10~7lU/L.30℃诱导培养96 h、甲醇添加1%、pH值6.0、DO 20%、0.25%～0.4%甲醛灭活,获得高活性的、安全的IFN.仔猪免疫后临床症状正常,未出现病理学变化.猪α-IFN体外抗病毒活性高,发酵后的抗病毒活性未下降,免疫动物未产生临床症状和病理变化,可用于临床治疗病毒性疾病.     

干扰害虫生殖行为的弦音器瞬时感受器电位香草酸通道调节剂研究进展

瞬时感受器电位(transient receptor potential, TRP)通道是细胞膜上一类重要的阳离子通道,参与昆虫视觉、嗅觉、听觉、温度感知及机械感知等感觉功能的形成。其中瞬时感受器电位香草酸 (transient receptor potential vanilloid,TRPV) 通道为TRP家族中的一类亚家族,其成员nanchung (Nan) 和inactive (Iav) 基因所编码的蛋白复合物是杀虫剂吡蚜酮、双丙环虫酯以及氟喹酮的分子靶标。研究表明,TRPV通道调节剂类药剂的作用机制不同于传统的神经毒性杀虫剂。如吡蚜酮和氟喹酮会抑制桃蚜Myzus persicae的取食行为;吡蚜酮通过作用于昆虫的弦音感受器,使东亚飞蝗Locusta migratori表现出后足抬起并伸展的独特中毒症状;吡蚜酮和氟喹酮能影响黑腹果蝇Drosophila melanogaster的重力感受和听觉感受,破坏其正常的负趋地性行为;吡蚜酮能够干扰褐飞虱Nilaparvata lugens和黑腹果蝇的生殖行为,有效抑制其下一代种群数量,从而表现出持效期长的特点。我国褐飞虱田间种群已对吡蚜酮普遍产生中等到高水平抗性,白背飞虱Sogatella furcifera和灰飞虱Laodelphax striatellu对吡蚜酮的抗性水平虽然较低,但也呈逐年升高趋势;烟粉虱Bemisia tabaci对吡蚜酮和双丙环虫酯的抗性水平相对较低。细胞色素P450家族成员CYP6CS1、CYP6CM1及CYP6CW1等参与了现阶段害虫对吡蚜酮的代谢抗性,但还未发现害虫对TRPV通道调节剂的靶标抗性。本文主要从TRPV通道调节剂的发现、毒理学机制、抗性现状、抗性机制及抗性适合度代价等方面的研究进展进行了系统阐述,可为该类药剂的深入研究及科学使用提供参考。     

单端孢霉烯族毒素抑制动物生长作用的研究进展

单端孢霉烯族毒素是主要的饲料污染物,包括T-2毒素、脱氧雪腐镰刀菌烯醇(DON)等,具有较强的毒性作用,能引起动物体多种病理变化。其毒性作用能改变真核翻译起始因子2α(EIF2α)、丝裂原激活的蛋白激酶(MAPK)、热休克蛋白90(Hsp90)、胰岛素样生长因子1(IGF-1)等细胞因子的活性,调节多种胺酰tRNA合成酶的活性,进而抑制蛋白质合成,阻滞动物生长。论文从单端孢霉烯族毒素对生长激素影响的角度,综述了该类毒素对动物生长的抑制作用,以期为阐明单端孢霉烯族毒素抑制动物生长的毒性作用机制奠定基础。     

Airway obstruction in a dog after Dieffenbachia ingestion

Objective – To describe a case of Dieffenbachia ingestion in a dog presented for dysphagia and airway obstruction successfully treated with a temporary tracheostomy and supportive care beyond that reported in the veterinary literature. Case Summary – An 8‐year‐old male neutered Labrador Retriever, weighing 30 kg, was presented with the complaint of choking and gagging. Abdominal radiographs showed that he had a distended stomach full of foreign material and a gastrotomy was performed. After receiving preanesthetic medication, the dog developed inspiratory stridor and during anesthetic induction, marked oropharyngeal swelling complicated tracheal intubation. During surgery a large amount of dog bedding and Dieffenbachia plant material was removed. Because of the severity of the oropharyngeal swelling, the dog required a temporary tracheostomy and treatment for an acute allergic reaction related to the Dieffenbachia ingestion. The patient was discharged after 6 days in the hospital and had no significant complications. New or Unique Information Provided – To our knowledge, this is the first reported case of successful treatment of an airway obstruction related to the toxicity of Dieffenbachia ingestion.