野黄芩苷抗肠出血大肠杆菌感染作用

为了更好的分析野黄芩苷对肠出血性大肠杆菌(enterohemorrhage E.coli,EHEC)感染的保护作用,本研究通过原核表达,亲和层析的方法纯化志贺毒素(Stx),利用细胞表型,通过LDH方法检测野黄芩苷对Stx活性的抑制作用。32 mg/L的野黄芩苷对Stx的抑制率为67%。通过动物试验,发现野黄芩苷对Stx中毒小鼠具有显著的保护作用,其保护率为70%。本研究中,我们筛选到了一种常用的中药黄酮类化合物,野黄芩苷可显著降低stx2引起的细胞死亡,同时有效抑制肠出血。基于以上结果,野黄芩苷可以作为抗Stx的潜在化合物。     

羊梭菌病快速鉴别PCR方法的建立及初步应用

根据GenBank已公布的产气荚膜梭菌和腐败梭菌的α毒素基因序列,分别设计并合成针对2种α毒素基因的特异性引物,通过扩增条件的优化,建立快速鉴别产气荚膜梭菌和腐败梭菌的双重PCR方法。特异性试验显示,产气荚膜梭菌和腐败梭菌参考菌株均扩增出了相应的预期目的条带,而大肠埃希菌、沙门菌、金黄色葡萄球菌和链球菌则均未能扩增出相应条带。灵敏度试验结果显示,产气荚膜梭菌和腐败梭菌基因组DNA最低检测量分别为17.95pg/μL和1.261pg/μL。应用该方法对样品进行检测,其中5份为产气荚膜梭菌阳性。成功建立了特异性强、敏感性高的双重PCR方法,可以有效进行产气荚膜梭菌和腐败梭菌的快速鉴别,对羊梭菌病病原快速鉴定及流行病学调查具有重要意义。     

Magnetic resonance imaging appearance of the brain and cervical spinal cord in an edema disease affected pig

A 7‐week‐old male pig was presented with signs of a central nervous system disorder. An MRI of the head and cervical spine was performed immediately after euthanasia. The MRI revealed multifocal bilaterally symmetric T2‐weighted hyperintense lesions in the brain and spinal cord, likely due to a toxic metabolic process. Histopathological examination supported the MRI findings and confirmed the diagnosis of edema disease due to Shiga‐like toxin produced by Escherichia coli. This is the first case published of the MRI findings in an edema disease affected pig.     

Chronic granulomatous pneumonia and lung rupture secondary to aspiration of activated charcoal in a French Bulldog

A 4‐year‐old, spayed female French Bulldog was presented for respiratory distress and suspected aspiration pneumonia after oral administration of activated charcoal for possible ingestion of a suspected toxic dose of trazodone. The patient had a moderate volume of pleural effusion, which contained free and intracellular black particulate matter consistent with charcoal. Due to presumed charcoal aspiration with subsequent lung rupture, the right middle and right caudal lung lobes were surgically removed. Histology revealed abundant black debris consistent with charcoal and severe granulomatous inflammation. Based on the clinical, gross, and histologic findings, a diagnosis of severe, chronic, locally extensive, aspiration pneumonia and lung rupture with secondary pleuritis and mediastinitis due to charcoal aspiration was made. Aspiration pneumonia is the main complication of activated charcoal administration, which can incite extensive, granulomatous inflammation in the respiratory tract. To the authors’ knowledge, this is the first report describing the cytologic and histologic findings associated with inadvertent charcoal aspiration in a veterinary species.     

利用胚性细胞悬浮系研究香蕉枯萎病抗性离体筛选技术

以香蕉(Musa spp. AAA group)胚性细胞悬浮系(Embryogenic Cell Suspension,ECS)为试材,进行抗枯萎病离体筛选技术研究。首先测试不同的γ射线(60Co)辐射剂量对ECS植株再生能力的影响;在此基础上,以不同浓度的枯萎病病原菌毒素粗滤液(FOC)为选择压力,研究FOC对ECS植株再生能力的影响,并进行离体抗性筛选。结果表明,ECS的植株再生能力与辐射剂量之间呈负相关,半致死剂量为70～80Gy。同样地,未经辐射处理的ECS其植株再生能力也随着FOC体积分数的增加而急剧下降,但经辐射处理过的ECS其植株再生能力与CK相比成倍地增加;当FOC体积分数达到12%后,只有从经80Gy辐射后的ECS获得了再生植株。这表明ECS耐FOC的能力随着辐射剂量的增加而增强。     

Attribution of human infections with Shiga toxin‐producing Escherichia coli (STEC) to livestock sources and identification of source‐specific risk factors,The Netherlands (2010–2014)

Shiga toxin‐producing Escherichia coli (STEC) is a zoonotic pathogen of public health concern whose sources and transmission routes are difficult to trace. Using a combined source attribution and case–control analysis, we determined the relative contributions of four putative livestock sources (cattle, small ruminants, pigs, poultry) to human STEC infections and their associated dietary, animal contact, temporal and socio‐econo‐demographic risk factors in the Netherlands in 2010/2011–2014. Dutch source data were supplemented with those from other European countries with similar STEC epidemiology. Human STEC infections were attributed to sources using both the modified Dutch model (mDM) and the modified Hald model (mHM) supplied with the same O‐serotyping data. Cattle accounted for 48.6% (mDM) and 53.1% (mHM) of the 1,183 human cases attributed, followed by small ruminants (mDM: 23.5%; mHM: 25.4%), pigs (mDM: 12.5%; mHM: 5.7%) and poultry (mDM: 2.7%; mHM: 3.1%), whereas the sources of the remaining 12.8% of cases could not be attributed. Of the top five O‐serotypes infecting humans, O157, O26, O91 and O103 were mainly attributed to cattle (61%–75%) and O146 to small ruminants (71%–77%). Significant risk factors for human STEC infection as a whole were the consumption of beef, raw/undercooked meat or cured meat/cold cuts. For cattle‐attributed STEC infections, specific risk factors were consuming raw meat spreads and beef. Consuming raw/undercooked or minced meat were risk factors for STEC infections attributed to small ruminants. For STEC infections attributed to pigs, only consuming raw/undercooked meat was significant. Consuming minced meat, raw/undercooked meat or cured meat/cold cuts were associated with poultry‐attributed STEC infections. Consuming raw vegetables was protective for all STEC infections. We concluded that domestic ruminants account for approximately three‐quarters of reported human STEC infections, whereas pigs and poultry play a minor role and that risk factors for human STEC infection vary according to the attributed source.     

四种Bt毒素蛋白对二点委夜蛾幼虫毒力测定及中肠组织病理学变化

为更好地了解苏云金芽胞杆菌Bacillus thuringiensis毒素蛋白对二点委夜蛾Athetis lepigone的毒力以及作用机理,通过饲喂含有Cry1Ac、Cry1Ab、Cry2Ab和Vip3Aa四种不同Bt毒素蛋白饲料,测定Bt毒素蛋白对二点委夜蛾幼虫的毒力,并观察取食4种毒素蛋白后幼虫中肠组织的病理学变化。结果显示,二点委夜蛾幼虫取食毒素蛋白后72 h,Cry1Ab和Cry1Ac毒素蛋白对二点委夜蛾幼虫的杀虫活性较高,校正死亡率为84.7%和76.4%;Vip3Aa和Cry2Ab毒素蛋白的毒力较弱。二点委夜蛾幼虫取食4种Bt毒素蛋白后,中肠柱状细胞微绒毛脱落,杂乱地分散在肠腔内,杯状细胞变形和腔内微绒毛脱落,线粒体和内质网等变形破裂,细胞核的核膜消失、核质凝聚和形状发生变化,经Cry1Ab和Cry1Ac毒素蛋白处理后中肠细胞的病变症状和速度明显高于Cry2Ab和Vip3Aa毒素蛋白处理。表明Cry1Ab和Cry1Ac毒素蛋白对二点委夜蛾幼虫杀虫活性较高,显著高于Cry2Ab和Vip3Aa毒素蛋白,且对其中肠细胞的破坏作用也较强。     

国医大师张学文辨治肺癌经验

国医大师张学文认为肺癌是因毒邪侵淫、情志内伤等导致脏腑失调,正气虚弱,气滞血瘀,痰浊内生,毒痰瘀互结,壅结于肺,日久恶变成癌积,临床从气阴亏虚型、热毒内蕴型、痰浊内阻型、毒瘀互结型、阴阳两虚型辨治。治当扶正祛邪,以益气养阴、活血散结、化痰解毒为原则,并应将扶正祛邪贯穿肺癌治疗的全过程。     

多发性骨髓瘤中医病机分析及证治思路

多发性骨髓瘤（multiple myeloma,MM）是一种浆细胞恶性肿瘤,随年龄增长发病率升高,多经意义未明的单克隆免疫球蛋白血症（monoclonal gammopathy of undetermined significance,MGUS）发展而来。本文在前人经验基础上,提出了完整的肾虚血瘀证治思想;认为肾虚无制、瘀毒肆虐是MM发生的关键;提出了补肾阴、扶正气、破瘀毒、解症状基本治法,使MM恢复到MGUS状态。     

棉秆生物炭对大丽轮枝菌生长及毒素作用的影响

棉花黄萎病难以防治的根源在于大丽轮枝菌Verticillium dahliae Kleb在土壤中形成的微菌核能抵抗不良环境,并在土壤中长期存活,将棉秆加工成生物炭施入棉田,可克服棉秆直接还田的缺点,从源头上防止黄萎病菌进入土壤。为探索棉秆生物炭还田对棉花黄萎病原菌的影响机理,采用液态摇床培养及平皿固态培养法研究生物炭对大丽轮枝菌菌丝生长及微菌核萌发的影响;通过平皿内棉花和甜瓜种子发芽试验研究生物炭对大丽轮枝菌毒素的减毒作用。结果表明:液态培养条件下,棉秆生物炭对大丽轮枝菌菌丝生长抑制作用不明显,在固态培养下对菌丝体生长有一定促进作用;生物炭能减慢微菌核的萌发速率,但对最终萌发率无影响;液态培养中加入棉秆生物碳对大丽轮枝菌毒素有较强的减毒作用。在摇床培养中期,加入2.0 g·L-1生物炭处理与对照棉种在培养12天时的发芽率分别为53.3%与33.3%(P0.05);前期、中期及后期加入0.5 g·L-1生物炭处理的棉花幼苗总长度分别为对照的4.9、2.1倍及3.2倍;加入棉秆生物碳处理甜瓜种子发芽率、胚根长度、胚轴长度及总苗长较对照均有不同程度增加。表明棉杆生物炭对棉花黄萎病菌大丽轮枝菌菌丝生长、微菌核萌发的抑制作用较弱,对大丽轮枝菌毒素危害有较强的减毒作用。