Transiently Transfected Mammalian Cell Cultures: An Adaptable and Effective Platform for Virus-like Particle-Based Vaccines against Foot-and-Mouth Disease Virus

RNA viruses, such as foot-and-mouth disease virus (FMDV), have error-prone replication resulting in the continuous emergence of new viral strains capable of evading current vaccine coverage. Vaccine formulations must be regularly updated, which is both costly and technically challenging for many vaccine platforms. In this report, we describe a plasmid-based virus-like particle (VLP) production platform utilizing transiently transfected mammalian cell cultures that combines both the rapid response adaptability of nucleic-acid-based vaccines with the ability to produce intact capsid epitopes required for immunity. Formulated vaccines which employed this platform conferred complete protection from clinical foot-and-mouth disease in both swine and cattle. This novel platform can be quickly adapted to new viral strains and serotypes through targeted exchanges of only the FMDV capsid polypeptide nucleic acid sequences, from which processed structural capsid proteins are derived. This platform obviates the need for high biocontainment manufacturing facilities to produce inactivated whole-virus vaccines from infected mammalian cell cultures, which requires upstream expansion and downstream concentration of large quantities of live virulent viruses.     

广角、水牛角和黄牛角中无机元素的比较研究

对广角、水牛角和黄牛角中的钙、镁、铁、锌、铜、锰、钴和铅进行了测试，结果显示３种角既有一定的相似性，又有差异性。     

牛胆粉指纹图谱模式识别及多组分测定研究

针对牛胆粉药材中主要活性组分的化学性质,使用具有较好专属性及准确度的HPLC-ELSD建立可准确反映其内在质量的指纹图谱及主要活性组分含量测定方法。采用Phenomenex Gemini C18(4.6 mm×250 mm,5μm)色谱柱,以10 mmol乙酸铵水溶液与乙腈作为流动相进行梯度洗脱,柱温40℃,ELSD漂移管温度为110℃,ELSD氮气流量为2.8 L·h-1。测得13批牛胆粉的甘氨胆酸、甘氨去氧胆酸、牛磺胆酸和牛磺去氧胆酸的含量,并使用化学计量学对牛胆粉药材指纹图谱进行预处理和模式识别分析。结果样品中甘氨胆酸、甘氨去氧胆酸、牛磺胆酸和牛磺去氧胆酸的平均质量分数分别为(25.2±17.0)%,(4.1±3.4)%,(24.5±20.0)%,(5.2±3.8)%,4者质量分数总和占牛胆粉(59.0±26.0)%。化学计量学分析结果表明自制样品与市售样品差异较大,指纹图谱之中有4处区域的色谱信号较小,但对这种差异的影响却不容忽视。所建HPLCELSD方法简便快速,适合从定性和定量的角度对牛胆粉进行质量评价与控制,可以为完善该药材质控标准提供科学依据。     

莱菔硫烷对过氧化氢诱导牛眼小梁细胞氧化应激损伤的保护作用

背景 研究表明小梁网组织的氧化应激损伤是开角型青光眼的基本病理过程之一,莱菔硫烷(SFN)可通过激活Nrf2/ARE通路发挥其抗氧化应激作用,但其是否可对氧化应激损伤的小梁细胞发挥作用目前尚不清楚. 目的 探讨SFN对H2O2诱导的牛眼小梁细胞氧化应激损伤的防护作用. 方法 采用组织块培养法对新鲜摘取的黑牛眼球小梁组织进行小梁细胞原代培养,将第3代牛小梁细胞以1x 103/孔的细胞密度接种于96孔板中培养24 h后将细胞分为4个组,空白对照组加入100μl无血清培养基,H2O2组细胞在空白对照组的基础上加入100 μl终浓度为100 μmol/L H2O2建立细胞氧化应激损伤模型,SFN组在培养液中加入100μl终浓度为10μmol/L SFN,而SFN+H2O2组在SFN组的基础上加入100 μmol/L H2O2,细胞培养后6h采用CCK-8法检测各组牛眼小梁细胞活力,采用Annexin V-FITC/PI双染流式细胞仪检测各组细胞的凋亡率.结果 传至第3代的细胞呈梭形,形状和大小较均一,细胞质丰富,可见色素颗粒,核仁大.H2O2组和SFN+H2O2组相对细胞活力分别为空白对照组的(67.00±1.27)％和(80.00±6.25)％,其中SFN+H2O2组相对细胞活力低于空白对照组和SFN组,但明显高于H2O2组,差异均有统计学意义(均P＜0.01).空白对照组、H2O2组、SFN组和SFN+H2O2组细胞凋亡率分别为(11.33±0.77)％、(32.31±1.03)％、(10.44±0.68)％和(17.68±0.21)％,各组间总体比较差异均有统计学意义(F-539.96,P＜0.01),其中SFN+H2O2组细胞凋亡率明显低于H2O2组但高于空白对照组和SFN组,差异均有统计学意义(均P＜0.01).结论 SFN可以增强H2O2诱导的牛眼小梁细胞的抗氧化应激能力,减轻氧化应激对牛眼小梁细胞的损伤.     

牛视网膜提取物对人-鼠杂合细胞抗体产生的影响

目的：探讨牛视网膜提取物对人－鼠杂合细胞抗体产生的影响。方法：在ＰＲＭＩ１６４０完全培养基（ＣＭ）中加入２０ｍｇ／Ｌ牛视网膜提取蛋白,配成牛视网膜培养基（ＢＲＥＭ）。用ＭＴＴ测定、细胞克隆技术、夹心ＥＬＩＳＡ方法和染色体分析,比较人－鼠杂合细胞Ｇ１２在两种培养条件下的细胞活力、克隆效率、人ＩｇＭ分泌和人染色体阳性细胞比率之间的差异。结果：用ＢＲＥＭ培养的Ｇ１２细胞活力高于用ＣＭ培养（Ｐ＜００５）。用ＢＲＥＭ培养的Ｇ１２细胞克隆中分泌人ＩｇＭ者占１２／２４,用ＣＭ培养的克隆只占２／４７。Ｇ１２细胞传代培养３个月后,用ＢＲＥＭ培养的上清人ＩｇＭ水平Ａ４９０为０３３５±００５０,用ＣＭ培养的上清为００７０±００２７（Ｐ＜００５）。前者含人染色体阳性的细胞为２０％,后者２５％,两者间没有差异（Ｐ＞００５）。结论：添加牛视网膜提取物的培养基可以提高人－鼠杂合细胞的活力和人ＩｇＭ抗体的分泌能力。维持人源性ＩｇＭ持续分泌的条件不仅取决于杂合细胞中人染色体的存在和稳定,还有其它未知因素在起作用,牛视网提取蛋白可以提供这方面的需要。     

牛若干脏器新鲜组织RNA对体外瘤细胞的抑制作用

用十二烷基硫酸钠热酚法,从牛各脏器组织中提取并测定了RNA的含量。结果表明,牛胰腺中RNA含量为其他脏器组织的3～4倍。在体外做对瘤细胞杀伤作用的实验结果表明,牛胰腺和心脏RNA对瘤细胞的杀伤作用最大,其他组织的RNA也有一定程度的杀伤作用。     

Outcome of Three Commercial Serum ELISAs and Faecal Detection of Mycobacterium avium subsp. paratuberculosis in Consecutive Samples from a Cattle Herd with Low Prevalence of Paratuberculosis (Johne’s Disease)

Paratuberculosis (Johne’s disease) in ruminants is caused by Mycobacterium avium subsp. paratuberculosis (MAP). Owing to the lack of accurate laboratory tests, diagnosis is challenging in subclinically infected cattle. To evaluate the long‐term performance of serum ELISAs for the detection of paratuberculosis in a dairy herd with low MAP‐prevalence, three investigations of all the cows and the consecutive testing of 33 cows suspected to be infected with MAP and 30 cows classified as MAP free were performed over a period of 22 months. Blood samples were tested by three commercial serum ELISAs, MAP shedding was detected by bacteriological culture and polymerase chain reaction (PCR). The ELISA results varied in a wide range in the herd investigations with 1.2% to 18.8% positive samples, the faecal samples were positive for MAP between 1.8% and 4.9% in the three herd investigations. Over the study period, ELISA‐positive serum samples varied between 0.0% and 69.7% in MAP‐suspicious and 0.0% and 17.6% in MAP‐unsuspicious cows with a poor correlation between ELISAs and faecal shedding. The correlation coefficient of the optical density values of the three ELISAs varied between 0.348 and 0.61. Evidence of cow specific variations of residuals was found in all linear models. The linear mixed models showed relevant contribution of cow specific variation in explanation of the residual variances. They also showed significant effects of the explanatory ELISA, the group (MAP‐suspicious or MAP‐unsuspicious) and the time of sampling. It can be concluded that the choice of the laboratory test significantly influences the outcome of the testing for MAP and that none of the three ELISAs can be thoroughly recommended as single test for the early diagnosis of paratuberculosis in cattle. Test results should always be interpreted with caution to avoid erroneous decisions and the disappointment of those engaged in the abatement of paratuberculosis.     

Detailed evaluation of a newly attained fungal pigment from Monascus purpureus in meat burgers

Beef burgers with red pigment extracted from Monascus purpureus, used as a natural colouring agent, were examined for chemical compositions, physical properties, microbiological aspects and organoleptic evaluation. Beef burgers with Monascus pigment showed higher nutritional values compared with control samples. Nutritional values were proportionally enhanced by increasing pigment concentration. Synthetic dye samples had the lowest values of nutrients. Cooking loss percentage and water holding capacity were lower in all treatments compared with control samples, and vice versa for plasticity. The initial total bacterial count, Staphylococcus aureus count and coliform count were determined. Extending storage period up to 90 days severely reduced all tested microorganisms. By increasing the M. pigment concentration, the colour was significantly increased. Insignificant differences in colours were noticed among various treatments. Flavour and body and texture scores were insignificantly different. Microbial inhibition percentage of beef burger samples was increased by increasing the Monascus pigment concentration up to 0.8 g/kg.     

Transmission of Brucellosis from Elk to Cattle and Bison,Greater Yellowstone Area,USA, 2002–2012

Bovine brucellosis has been nearly eliminated from livestock in the United States. Bison and elk in the Greater Yellowstone Area remain reservoirs for the disease. During 1990–2002, no known cases occurred in Greater Yellowstone Area livestock. Since then, 17 transmission events from wildlife to livestock have been investigated.