Thoracoscopic biopsy of lung tumors using a Roeder's loop in dogs

Thoracoscopic biopsies were taken from four dogs with lung tumours using a Roeder's loop. A Roeder's loop is used to collect pulmonary tissue samples for histopathological analyses. In all the animals tissue biopsy using a Roeder's loop enabled to collect a relatively large specimen of the lung tumor tissue.     

Pharmacokinetics and bioavailability of cefquinome in healthy piglets

A study on bioavailability and pharmacokinetics of cefquinome in piglets was conducted after intravenous (i.v.) and intramuscular (i.m.) administrations of 2.0 mg/kg of body weight, respectively. Plasma concentrations were measured by high‐performance liquid chromatography assay with UV detector at 268‐nm wavelength. Plasma concentration–time data after i.v. administration were best fit by a two‐compartment model. The pharmacokinetic values were distribution half‐life 0.27 ± 0.21 h, elimination half‐life 1.85 ± 1.11 h, total body clearance 0.26 ± 0.08 L/kg·h, area under curve 8.07 ± 1.91 μg·h/mL and volume of distribution at steady state 0.46 ± 0.10 L/kg. Plasma concentration–time data after i.m. administration were also best fit by a two‐compartment model. The pharmacokinetic parameters were distribution half‐life 0.88 ± 0.42 h, elimination half‐life 4.36 ± 2.35 h, peak concentration 4.01 ± 0.57 μg/mL and bioavailability 95.13 ± 9.93%.     

LPS structure influences protein secretion in Salmonella enterica

In this study we have compared protein secretion in the wild type of S. Typhimurium and the rfaC mutant. We found out that the rfaC mutant was defective in protein secretion. In addition, the rfaC mutant was defective in its invasion into an IPEC-J2 porcine epithelial cell line and also in motility in semisolid agar. Consistent with this, reduced flagella numbers were observed in the rfaC mutant. In the rfaC mutant, there were no defects in flagellin expression as detected by western blot and immune electron microscopy which demonstrated equal amounts of flagellin in the cytoplasm of both the rfaC mutant and the wild-type S. Typhimurium. However, in the wild-type strain only, the flagellin was assembled to spatially restricted areas on the inner side of cytoplasmic membrane. The oligosaccharide core of LPS is therefore required for the assembly of flagella and T3SS secretion machinery followed by protein secretion.     

动物副黏病毒感染与对策思考

尼帕病毒(Ni V)和亨德拉病毒(HeV)属于副黏病毒亚科的亨尼帕病毒属的成员。Ni V和HeV感染引起新的两种重要的人兽共患传染病。有关APMV-1(NDV)的发病和流行以及病原学研究认为APMV-1不断发生演化,新的基因型不断产生,对不同宿主的致病力不断变化,病毒感染的宿主谱不断扩大。本文简要介绍两种新的人兽共患传染病和APMV-1对鹅、鸭、猪的感染研究现状,就APMV-1宿主感染谱与演化加以分析,思考新的动物副黏病毒病防控对策。     

黄曲霉毒素污染鸡饲料的生物脱毒

通过2个试验研究接种nocardia corynebacte-roides(NC)细菌对黄曲霉毒素污染肉鸡饲料的生物脱毒作用。第1个试验研究了NC细菌的致病性(安全性);第2个试验对脱毒饲料的营养价值进行了评估。将玉米分为2份,其中1份污染黄曲霉毒素,再将这2份玉米分别分为2小份,其中1小份接种NC细菌,然后使用这4个玉米样品配制4种玉米-豆粕日粮,形成完全随机的2×2析因分析设计,包括污染或不污染AF、接种或不接种NC细菌。试验选用100只1日龄Ross 308公雏,分为4个处理组,每个处理组5个重复,每个重复5只鸡。每周记录体重和耗料量,并从每个重复组中选择一只鸡屠宰,对肝脏、肾脏、法氏囊、胰脏以及小肠(包括十二指肠、盲肠、结肠)进行组织病理学分析,同时对小肠的3个部分进行电子显微镜分析,在21日龄试验结束时,每个重复组再屠宰1只鸡,测定肝脏中水分和脂肪含量以及AF残留量。3周的试验结果表明,处理组之间各项病理指标无显著差异(P>0.05)。第2个试验增大了AF的污染量(800和1200μg/kg饲料),其他与试验1相同。结果表明,处理组之间在体重、肝脏脂肪含量和AF残留量上存在显著差异(P<0.05);肝脏、十二指肠以及肾脏的损伤严重程度也存在显著差异;电子显微镜扫描结果表明,AF严重损伤肠黏膜紧密连接处。综上所述,NC细菌对鸡是安全的,可用于AF污染肉鸡饲料的生物脱毒。     

Retrospective – systematic study and quantitative analysis of cellular proliferation and apoptosis in normal, hyperplastic and neoplastic perianal glands in dogs

Neoplasms in the perianal region are frequently diagnosed in dogs. The aetiology is unknown, and most of them are benign. In this study, 240 neoplasms of the perianal glands of dogs were retrieved from the Department of Pathology archives of the Faculty of Veterinary Medicine and Zootechny of University of São Paulo (FMVZ/USP), from 1984 to 2004. All 240 cases were re‐examined by two pathologists. Nine cases (4%) were diagnosed as hyperplasia, 49 (20%) as group I adenoma, 81 (34%) were classified as moderately differentiated adenomas of the group II, 46 (19%) were poorly differentiated adenomas of group II, 48 (20%) were carcinoma of the group III according to the classification proposed by Berrocal, and 7 (13%) were other kind of tumours. Males over 8 years of age were predominantly affected. Cell proliferation was quantified by counting proliferating cell nuclear antigen (PCNA) positive nuclei, and apoptosis was quantified by counting fluorescent eosin‐stained apoptotic corpuscles (AC) in normal tissue, hyperplasia and in different histologic types of neoplasia of these glands. A parallel pattern of increase in both parameters (cell proliferation and apoptosis) was obtained. The net growth index (NGI), represents how much a cell population is proliferating or dying and was achieved by dividing the mean PCNA count in 1000 cells by the mean AC stain count in 1000 cells. NGI was different between hyperplasia and neoplasia; group I adenomas have a much higher potential of growth, and NGI decreases from benign towards malignant lesions. These results show up the importance of studying cell proliferation and apoptosis to understand the carcinogenesis of dog perianal gland.     

非洲猪瘟防控的经验和误区

自从2018年8月我国报告首例非洲猪瘟疫情以来,经过3年多的艰难探索,我们面对非洲猪瘟疫情从最初的恐惧和束手无策,到现在的精准清除和“与狼共舞”,疫情防控从被动应对进入到常态化管理和无疫小区建设阶段;非洲猪瘟可防可控的预测得到了实践证明。但是由于我国幅员辽阔,养猪模式多样,疫情防控水平参差不齐;非洲猪瘟疫情零星散发的风险持续存在。下面就我们的观察和调查,对近年来非洲猪瘟防控上的一些经验和误区进行简要分析。     

空气负氧离子对鸡胚和雏鸡生长发育的影响

将星杂288鸡种蛋960枚随机分为4组,进行3周孵化试验,各组空气负氧离子浓度分别为200000、100000、50000和40个/cm3。再取孵出的雏鸡120只随机分为4组,进行6周饲养试验,所设负氧离子浓度分别为100000、50000、25000和30个/cm3。结果表明:(1)200000和100000个/cm3负氧离子有助于胚胎的生长发育,能提高种蛋的孵化率;(2)50000个/cm3负氧离子可降低雏鸡料肉比和死亡率,并能促进雏鸡的生长发育,改善雏鸡的某些血液生理生化指标;(3)25000个/cm3以上的负氧离子对孵化和育雏的空气环境有一定净化作用。