T-2毒素研究进展

T-2毒素是污染我国饲料的主要霉菌毒素,主要危害动物的造血组织和免疫器官,引起出血性综合征,出现白细胞减少、贫血,使胃肠道功能受损等,对畜禽健康和畜牧业生产的危害很大.本文主要从T-2毒素的一般性质、产毒菌株、毒性效应、毒性机制及预防控制等方面作了论述.     

RABBIT HEMORRHAGIC DISEASE VIRUSES DETECTED IN PET RABBITS IN A COMMERCIAL LABORATORY IN EUROPE

Rabbit hemorrhagic disease (RHD) is an important cause of disease and mortality in wild and domestic European rabbits (Oryctolagus cuniculus) throughout the world. Testing for 2 distinct RHD virus types (RHDV/RHDVa and RHDV2) was carried out on samples collected from 684 rabbits submitted from veterinary practices and private owners throughout Europe between January 2015 and June 2017. Four (0.6%) were positive for RHDV/RHDVa and 257 (37.4%) were positive for RHDV2. RHDV/RHDVa was detected in individual samples from Germany and the Netherlands, while RHDV2 was found in animals from Germany, Great Britain, Luxembourg, The Netherlands, Spain, Switzerland, Poland, Belgium, Austria, Sweden, and Finland.     

含氟废水深度处理的研究

以火力发电厂的废树脂为载体 ,制备了负载锆水合氧化物的氟离子吸附树脂 ,并探讨了该负载树脂对氟离子的吸附和脱附性能 .结果表明 :制备该负载树脂的适宜锆浓度为 0 5mol L ,负载树脂吸附和脱附的适宜pH值分别为4 0和 12 0 .该负载树脂的吸附符合Langmuir型吸附等温线 ,通过这种等温线可以得出 ,CF- =1mg L时负载树脂的平衡吸附量qe 为 5 0 0 0mg L .利用该负载树脂对模拟火电厂的含氟废水进行处理 ,取得了较好的效果 .     

鸡传染性贫血病毒VP1、VP2基因的表达及免疫原性研究

为探索鸡传染性贫血重组蛋白亚单位疫苗的可行性,将鸡传染性贫血病毒基因分别克隆到转移载体p Fast Bac HTA中,再将其分别转化DH10Bac感受态细胞得到相应的重组表达载体,转染昆虫细胞Sf21获得含有VP1、VP2基因的重组杆状病毒v Bac-VP1、v Bac-VP2,应用悬浮培养的Sf21细胞表达重组蛋白。SDS-PAGE及Western blotting结果证明,VP1、VP2基因在昆虫细胞中得到了表达,动物试验进一步证实,重组蛋白免疫SPF鸡可产生ELISA抗体,提示杆状病毒表达的VP1、VP2具有良好的免疫原性。     

用PCR方法检测猪圆环病毒Ⅱ型

建立了一种能特异性地扩增猪圆环病毒 型 (porcine circovirus type 2 ,PCV- 2 )核酸片段的 PCR方法 ,从疑似断奶猪多系统衰竭综合征 (PMWS)的感染病例的淋巴结和脾脏中扩增出了预期长度的 PCV- 2 DNA片段 ,用限制性内切酶 Eco R 酶切鉴定了 PCR产物的特异性。 PCR产物的核苷酸序列分析表明 ,与已报道的 PCV- 2 (Gen Bank Ac-cession num ber AF0 2 72 17)相关区域的核苷酸序列同源性均大于 96 %。首次证实了我国猪群中存在 PCV- 2感染的PMWS。     

胆酸负荷对妊娠后期绵羊母体和胎儿血浆IGF—2及其代谢物水平的影响

以绵羊及其胎儿为试验对象，研究了胆酸负荷对妊娠后期母体和胎儿血浆胰岛素样生长因子－2(in-sulin-like growth factor-2,IGF-2）及其代谢物水平的影响。将7只确知妊娠时间的绵羊分为试验组5只和对照组2只，试验前装置颈静脉瘘，在妊娠90h和104d2闪给试验组静脉灌注胆酸盐1．1mg/kg，给对照组静脉灌注等量生理盐水，妊娠120d时手术安装胎儿后肢胫前动脉血管瘘。每天采胎儿和母体的血样，分离血浆，测定血浆IGF－2和主要代谢物水平。同时测定胎儿出生时生长发育指标。结果表明：（1）试验组母羊IGF－2水平低于对照组，相反其胎儿IGF－2水平却高于对照组（P＜0．05）；（2）试验组母羊的总蛋白和乳酸水平分别比对照组35．64％；（3）试验组胎儿出生重比对照组小29．00％，胎龄短7．50d。因此认为，胆酸重复灌注可引起妊娠绵羊早产和胎儿出生重降低，而这可能与IGF－2和主要代谢物水平变化有关。     

Detection of γ-H2AX,a Biomarker for DNA Double-strand Breaks,in Urinary Bladders of N -Butyl- N -(4-Hydroxybutyl)-Nitrosamine-Treated Rats

To evaluate the potential role of DNA repair in bladder carcinogenesis, we performed an immunohistochemical analysis of expression of various DNA repair enzymes and γ-H2AX, a high-sensitivity marker of DNA double-strand breaks, in the urothelium of male F344 rats treated with N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN), a bladder-specific carcinogen. Our results clearly demonstrated that γ-H2AX aggregation was specifically generated in nuclei of bladder epithelial cells of BBN-treated rats, which was not found in untreated controls or mesenchymal cells. γ-H2AX-positive cells were detected not only in hyperplastic and neoplastic areas but also in the normal-like urothelium after BBN treatment. These data indicate that γ-H2AX has potential as a useful biomarker for early detection of genotoxicity in the rat urinary bladder. To the best of our knowledge, this is the first report demonstrating expression of γ-H2AX during bladder carcinogenesis.     

人胚胎角膜的肾上腺素能神经纤维分布及其特点

用乙醛酸诱发灾光技术研究了14－30周胎儿眼结膜的肾上腺素能神经纤维的分布。发现角膜巩缘的肾上腺素能神经纤维主要与角巩膜的血管伴行，纤维数量随胎龄增加而增加，角膜基质层于16周以后有少量纤维，角膜内皮层和上皮层未发现神经纤维。     

Associations among albuminuria, C-reactive protein concentrations, survival predictor index scores, and survival in 78 critically ill dogs

Background: Microalbuminuria and C‐reactive protein (CRP) are predictors of morbidity and survival in critically ill human patients. Hypothesis/Objectives: To evaluate results of microalbuminuria assays (untimed single‐sample urine albumin concentration [U‐ALB] and the urine albumin : creatinine ratio [UACR]), serum CRP, and survival predictor index (SPI2) scores as predictors of survival in critically ill dogs. Animals: Seventy‐eight dogs admitted to intensive care units at University of Tennessee (UT) and Colorado State University (CSU). Methods: Prospective observational study. Critically ill dogs were eligible for enrollment, unless euthanized because of financial constraints. Samples were collected within 3 hours of admission. Spearman's rank‐correlation coefficients were determined for U‐ALB, UACR, CRP, and SPI2. U‐ALB, UACR, CRP, and SPI2 were assessed for associations with 7‐ and 30‐day survival by Mann‐Whitney U‐tests and receiver operating characteristic (ROC) curves. P‐values < .0125 were considered significant. Results: UT (n = 49) and CSU (n = 29) patients did not differ significantly. Forty percent (31/78) of dogs died. SPI2 was inversely correlated with U‐ALB (r_s=?0.39, P < .001) and UACR (r_s=?0.41, P < .001). CRP was not correlated with SPI2 (P= .019), U‐ALB (P > .1), or UACR (P > .1). U‐ALB and UACR had very high correlation (r_s= 0.95, P < .001). SPI2, U‐ALB, and UACR differed significantly for survivors and nonsurvivors. SPI2, U‐ALB, and UACR had areas under the ROC curve (AUC) from 0.68 to 0.74 for survival prediction. Conclusions and Clinical Importance: Albuminuria and SPI2, but not CRP, are associated with survival in critically ill dogs. Suboptimal AUCs limit the value of microalbuminuria testing for clinical risk assessment. Additional studies are necessary to determine the usefulness of microalbuminuria testing in patient risk stratification for prospective research.