Development of Nucleic Acid Lateral Flow Immunoassay Detection Method for Foot-and-mouth Disease Virus

In this article, through the combination of nucleic acid probes and immune chromatography, a simple, sensitive and specific detection system——nucleic acid lateral flow immunoassay (NALFIA) for amplifing foot-and-mouth disease virus (FMDV) 3D RT-PCR products was established.An ultrasensitive nucleic acid biosensor (NAB) based on streptavidin-labeled gold nanoparticles dual labels and lateral flow strip biosensor (LFSB) were used in this system.The biotinylated goat anti-rabbit IgG was marked to the NC membrane as the alleged strip and the anti-digoxin antibody was labeled to the NC membrane to capture the digoxin probe.After assemblying gold-labeled strip and detecting RT-PCR products, the detection limit of NALFIA was 0.3×10^-3 to 3×10^-3 μg/μL.The NALFIA was compared with agar gel electrophoresis analysis, the results showed that the sensitivity of NALFIA was higher than agar gel electrophoresis.There was an excellent agreement between the two methods.NALFIA was a method with high sensitive, low cost and short time.In conclusion, this method provided a good alternative to detect FMDV.     

奶牛热应激危害与调控技术研究进展

论述了热应激对奶牛代谢、生产、繁殖、健康等方面的影响,以及通过环境、营养和育种技术措施调控奶牛热应激的国内外研究进展。     

DOPPLER MEASUREMENT OF SPLANCHNIC BLOOD FLOW DURING DIGESTION IN UNSEDATED NORMAL DOGS

The purpose of this study was to measure splanchnic blood flow during digestion in unsedated dogs by using duplex Doppler sonography. The study population consisted of 12 healthy dogs. Blood flow in the cranial mesenteric artery, the celiac artery, and the aorta was measured before a test meal and at 20, 60, and 90 minutes after eating. The following measurements were made or calculated: vessel diameter, peak systolic velocity, end diastolic velocity, mean velocity, resistive index, pulsatility index, and flow volume. There was a significant postprandial decrease in the resistive and pulsatility indices in both the cranial mesenteric (preprandial RI = 0.867, postprandial RI = 0.796, preprandial PI = 3.033, postprandial PI = 2.173) and the celiac (preprandial RI = 0.854, postprandial RI = 0.769, preprandial PI = 2.639, postprandial PI = 1.930) arteries. In both vessels the end diastolic velocity, the mean velocity, and the flow volume increased significantly postprandially. These changes occurred significantly earlier in the celiac artery than in the cranial mesenteric artery. The findings most likely correspond to postprandial splanchnic vasodilation. Doppler ultrasound provide a good methode of detecting changes in postprandial splanchnic blood flow in the dog.     

山羊亚硝酸盐中毒口液,尿液,棉签偶氮显色快速诊断方法的研究

建立山羊亚硝酸盐中毒模型,用棉签分别蘸取口液、尿液立即滴加偶氮试剂均显粉红色,中毒后１０～２０ｍｉｎ显浅粉红色;６０ｍｉｎ显深粉红色,随中毒症状加重,棉签显色相应加深,甚致变为棕红色。同时棉签显色加深和血液褐变程度加重与ＭＨｂ／Ｈｂ比值升高同步。此种诊断方法是诊断亚硝酸盐中毒的动物可靠、灵敏和快速的诊断方法。     

Pharmacokinetics and dynamics of mycophenolate mofetil after single‐dose oral administration in juvenile dachshunds

Mycophenolate mofetil (MMF) is recommended as an alternative/complementary immunosuppressant. Pharmacokinetic and dynamic effects of MMF are unknown in young‐aged dogs. We investigated the pharmacokinetics and pharmacodynamics of single oral dose MMF metabolite, mycophenolic acid (MPA), in healthy juvenile dogs purpose‐bred for the tripeptidyl peptidase 1 gene (TPP1) mutation. The dogs were heterozygous for the mutation (nonaffected carriers). Six dogs received 13 mg/kg oral MMF and two placebo. Pharmacokinetic parameters derived from plasma MPA were evaluated. Whole‐blood mitogen‐stimulated T‐cell proliferation was determined using a flow cytometric assay. Plasma MPA C_max (mean ± SD, 9.33 ± 7.04 μg/ml) occurred at <1 hr. The AUC_0–∞ (mean ± SD, 12.84±6.62 hr*μg/ml), MRT_inf (mean ± SD, 11.09 ± 9.63 min), T1/2 (harmonic mean ± PseudoSD 5.50 ± 3.80 min), and k/d (mean ± SD, 0.002 ± 0.001 1/min). Significant differences could not be detected between % inhibition of proliferating CD5+ T lymphocytes at any time point (p = .380). No relationship was observed between MPA concentration and % inhibition of proliferating CD5+ T lymphocytes (R = .148, p = .324). Pharmacodynamics do not support the use of MMF in juvenile dogs at the administered dose based on existing therapeutic targets.     

荷斯坦牛红细胞Na~+-K~+-ATP酶的研究进展

作者对荷斯坦牛红细胞Na+-K+-ATP酶的分子结构和基本特征、分布、作用机制、调控机制、生理功能、影响因素及其与热应激的关系进行了综述.     

PULSED WAVE-DOPPLER ULTRASONOGRAPHIC EVALUATION OF THE COMMON CAROTID ARTERY IN THE RESTING HORSE: PHYSIOLOGIC DATA

A pulsed wave-Doppler ultrasonographic evaluation of common carotid arterial blood flow was carried out on 63 healthy Italian Saddlebred horses. Vessel diameter and tracing morphology were evaluated were evaluated and blood flow parameters (systolic, diastolic and mean velocity, acceleration and deceleration of the systolic wave, cartid pulse volume) were calculated and correlated with class variables (sex, age and body weight). On the basis of the presence of an incisure in the ascending branch of the systolic curve, subjects were divided in two groups: one with a bifid systolic curve and the other with a monophasic aspect. Correlations between: 1) diameter of the vessel and body weight and 2) carotid pulse volume and flow velocity (systolic, diastolic and mean) were found. A greater systolic pulse volume was found in male subjects, in subjects with greater body weight and in those which had a monophasic systolic wave.     

Hsp70 enhances presentation of FMDV antigen to bovine CD4+ T cells in vitro

Foot-and-mouth disease virus (FMDV) is the causative agent of a highly contagious acute vesicular disease affecting cloven-hoofed animals, including cattle, sheep and pigs. The current vaccine induces a rapid humoral response, but the duration of the protective antibody response is variable, possibly associated with a variable specific CD4⁺ T cell response. We investigated the use of heat shock protein 70 (Hsp70) as a molecular chaperone to target viral antigen to the Major Histocompatibility Complex (MHC) class II pathway of antigen presenting cells and generate enhanced MHC II-restricted CD4⁺ T cell responses in cattle. Monocytes and CD4⁺ T cells from FMDV vaccinated cattle were stimulated in vitro with complexes of Hsp70 and FMDV peptide, or peptide alone. Hsp70 was found to consistently improve the presentation of a 25-mer FMDV peptide to CD4⁺ T cells, as measured by T cell proliferation. Complex formation was required for the enhanced effects and Hsp70 alone did not stimulate proliferation. This study provides further evidence that Hsp70:peptide complexes can enhance antigen-specific CD4⁺ T cell responses in vitro for an important pathogen of livestock.