我国和欧盟兽药质量监督抽检工作机制对比研究

为更好地完善我国兽药质量监督抽检计划,通过对欧盟药品抽检管理工作机制的研究,本文分析了欧盟和我国兽药监督抽检管理方式的不同,从抽检责任部门、抽检目的、抽检计划内容、抽检计划制定流程、抽检品种的遴选和检测参数的确定等6方面进行了对比分析,探讨我国兽药质量监督抽检工作的管理中可以借鉴的方面。     

Immune responses to commercial equine vaccines against equine herpesvirus-1, equine influenza virus, eastern equine encephalomyelitis, and tetanus

Horses are commonly vaccinated to protect against pathogens which are responsible for diseases which are endemic within the general horse population, such as equine influenza virus (EIV) and equine herpesvirus-1 (EHV-1), and against a variety of diseases which are less common but which lead to greater morbidity and mortality, such as eastern equine encephalomyelitis virus (EEE) and tetanus. This study consisted of two trials which investigated the antigenicity of commercially available vaccines licensed in the USA to protect against EIV, EHV-1 respiratory disease, EHV-1 abortion, EEE and tetanus in horses. Trial I was conducted to compare serological responses to vaccines produced by three manufacturers against EIV, EHV-1 (respiratory disease), EEE, and tetanus given as multivalent preparations or as multiple vaccine courses. Trial II compared vaccines from two manufacturers licensed to protect against EHV-1 abortion, and measured EHV-1-specific interferon-gamma (IFN-gamma) mRNA production in addition to serological evidence of antigenicity. In Trial I significant differences were found between the antigenicity of different commercial vaccines that should be considered in product selection. It was difficult to identify vaccines that generate significant immune responses to respiratory viruses. The most dramatic differences in vaccine performance occurred in the case of the tetanus antigen. In Trial II both vaccines generated significant antibody responses and showed evidence of EHV-1-specific IFN-gamma mRNA responses. Overall there were wide variations in vaccine response, and the vaccines with the best responses were not produced by a single manufacturer. Differences in vaccine performance may have resulted from differences in antigen load and adjuvant formulation.     

重组犬瘟热病毒F-H融合基因乳酸菌的构建及表达

为了构建重组犬瘟热病毒(CDV)F-H融合基因工程乳酸菌,采用重叠延伸PCR(SOE-PCR)技术扩增CDV F-H融合基因。将F-H融合基因亚克隆至穿梭载体p SIP409多克隆位点上,构建p SIP-F-H表达重组子,并电转化至植物乳杆菌NC8感受态细胞中。利用SDS-PAGE和Western blotting检测F-H融合蛋白的表达情况。结果表明,成功地扩增了CDV F-H融合基因,构建了p SIP-F-H重组表达质粒,并电转化至乳酸杆菌感受态细胞中。SDS-PAGE和Western blotting检测表明,重组乳酸杆菌表达了分子量约为62.96 ku的F-H融合蛋白,且该蛋白能与CDV阳性抗体反应,具有反应原性。     

山东省减抗背景下的中兽药产业调研分析

基于对山东省兽药生产企业和养殖企业中兽药生产和使用情况的调研,本文深入分析了我省中兽药发展现状和存在的问题,针对性地提出了中兽药产业发展的对策建议。需着力构建全产业链发展格局;不断释放市场创新创业活力;快速实现我省中兽药产业现代化;充分发挥好政策对产业引领作用;着力打造专业化人才队伍。并不断推进兽用抗菌药减量化示范行动等综合措施,从根本上遏制兽用抗菌药滥用,提倡使用中兽药等绿色高效产品的减抗行动,以期降低细菌耐药性的发生和发展,保障畜禽产品质量安全。     

Immunity to equine herpesvirus type 1 (rhinopneumonitis): in vitro lymphocyte response.

Twenty-two ponies were examined for serum-neutralizing (SN) antibody to equine herpesvirus type 1 and for in vitro lymphocyte transformation in the presence of viral antigen. Six ponies had undetectable levels of neutralizing antibody (titer less than 1:2) and had lymphocytes which did not respond in culture with viral antigen (stimulation index less than 2.0). Four ponies which had SN antibody to equine herpesvirus type 1 did not manifest lymphocyte transformation in vitro. The 12 remaining seropositive ponies had lymphocyte transformation with viral antigen in vitro (stimulation indexes from 2.0 to 23.5). Lymphocyte transformation was specifically suppressed when cells were grown in medium containing autologous serum. The temporal development of in vitro lymphocyte responsiveness and SN antibody in 3 specific-pathogenfree ponies after experimentally induced infection with equine herpesvirus type 1 is described.     

Alpha-adrenoceptors in equine digital veins: Evidence for the presence of both alpha1 and alpha2-receptors mediating vasoconstriction

Rings of equine digital vein examined under conditions of isometric tension recording constricted to alpha-adrenoceptor agonists with an order of potency of 5-bromo-6-[2-imidazolin-2-yl-amino]-quinoxaline bitartrate (UK 14304) = noradrenaline > 6-Allyl-2-amino-5,6,7,8-tetrahydro-4H-thiazolo-(4,5-d) azepine (BHT-920) > phenylephrine > dopamine > methoxamine. The maximum force generated was greatest for the non-selective agonist noradrenaline and lowest for the alpha₂-selective agonist BHT-920 with the other agonists between these two extremes. Selective inactivation of alpha₁-adrenoceptors (achieved by treating yohimbine-protected tissues with phenoxybenzamine) reduced the maximum responses of all agonists, the EC₅₀ values of UK 14304, BHT-920 and noradrenaline and increased the EC₅₀ values of phenylephrine and methoxamine. Prazosin (30 n M ) had no inhibitory effect on responses to low concentrations of BHT-920 and UK 14304 and caused competitive inhibition of responses to phenylephrine and noradrenaline giving pK_b values of 8.49 ± 0.18 and 8.23 ± 0.14, respectively. Yohimbine (0.1 μ M ) caused significant competitive inhibition of responses to BHT-920 and noradrenaline with calculated pK_b values of 8.43 ± 0.11 for BHT-920 and 7.43 ± 0.31 for noradrenaline and non-competitive inhibition of responses to UK 14304. 2-[2-methoxy-1,4-benzodioxan-2-yl]-2-imidazoline (RX 821002; 10 n M ) caused competitive inhibition of responses to BHT-920 (pK_b 9.04 ± 0.27) and dopamine (pK_b 8.2 ± 0.2). These data indicate that equine digital veins possess both post-synaptic alpha₁ and alpha₂-adrenoceptors.     

The effect of prostaglandin E1 on motility of the equine gut

Prostaglandin E1 was infused intravenously (25, 50 and 75 ng/kg/min) in three ponies. Changes in gastrointestinal mechanical and electrical activity were recorded from chronically implanted strain-gauge force transducers and electrodes. Dose-dependent responses were obtained: there were significant decreases in electrical spiking activity in the stomach, left large colon and small colon, with a corresponding decrease of activity in the left dorsal colon mechanogram. The small intestine was also affected, showing a decrease in both contraction rate and amplitude, which was more marked in the proximal jejunum than in the ileum. There was an association between these changes in gastrointestinal activity and the presence of discomfort and diminished gut sounds.     

马流感A/马/京防/74-1(H7N7)毒株HA基因的序列分析

流感病毒(Influenza Virus)根据血凝素(HA)和神经氨酸酶(NA)两种表面抗原蛋白分为不同的亚型,马流感I型(H7N7)和Ⅱ型(H3N8)是其中比较重要的两个亚型.本研究应用无特定病原体(SPF)鸡胚增殖马流感病毒A/马/京防/74-1(H7N7)毒株,TRIzol LS Reagent提取病毒RNA,RT-PCR扩增HA基因全片段,克隆到PMD18-T载体上,并进行了鉴定和序列测定.所获得的HA基因片段长1 727 bp,编码563个氨基酸残基.根据推导的氨基酸序列进行预测,有7个潜在的糖基化位点和16个半胱氨酸残基,通过序列分析推断,A/马/京防/74-1(H7N7)株病毒的HA来源于禽类,是一株通过基因重排出现的重组病毒.     

Agreement of SpO2, SaO2 and ScO2 in anesthetized cynomolgus monkeys (Macaca fascicularis)

Objective To assess the agreement between three measurements of arterial oxygen saturation (SpO₂, SaO₂ and ScO₂) in anesthetized cynomolgus monkeys. Study Design Prospective study. Animals Eleven mature, male cynomolgus monkeys (Macaca fasicularis). Methods Monkeys were anesthetized with intramuscular ketamine followed by intravenous propofol. The trachea of each was intubated and the lungs ventilated. Arterial oxygen saturation was measured with a Nonin 8500 V pulse oximeter, using a lingual clip on the cheek. Arterial blood samples were taken from an indwelling catheter. Inspired oxygen concentration was varied from 12 to 20%, and 88 paired arterial blood samples and saturation measurements were taken. Arterial oxygen saturation in the blood samples was measured using a cooximeter. The saturation was also calculated from the arterial oxygen tension using the Adair equation. The results were compared using Bland and Altman's method. Results The pulse oximeter readings were 2.7% higher than that of the cooximeter, with a limit of agreement of ?3.9 to 9.3%. The pulse oximeter readings were 1.8% higher than the calculated saturation, with a limit of agreement of ?6.5% to 10.1%. The cooximeter readings were 0.9% lower than the calculated saturation, with a limit of agreement of ?5.6% to 3.8%. Conclusions The agreement between SpO₂ and other measurements of arterial oxygen saturation in this study is typical for this technique. The bias and limits of agreement are consistent with reports in other species. Clinical relevance The Nonin 8500 V is a useful pulse oximeter for clinical use in primates.     

Studies on equine prematurity 3: Insulin secretion in the foal during the perinatal period

The factors influencing beta cell function in the foetal and neonatal foal have been investigated in chronically catheterised foetal foals and in newborn foals delivered either spontaneously at term or by induction at different gestational ages. Insulin was detected in the foetal plasma from as early as 150 days of gestation (term = 340 days) and during the last third of gestation the foetal beta cells responded to exogenous administration of glucose and arginine and to endogenous variations in the glucose level. Insulin secretion by the foetal beta cells was depressed by anaesthesia and surgery. At birth, there was a significant positive correlation between the plasma concentrations of insulin and glucose irrespective of the maturity at birth or type of delivery (r = 0.86, n = 39, P less than 0.01). The slope of this relationship was significantly less than that relating the postoperative foetal concentration but only when delivery was difficult or prolonged was the beta cell sensitivity to glucose completely abolished. At birth, there were no significant differences in the plasma concentrations of insulin or glucose between full term foals delivered spontaneously or by induction. However, the spontaneously delivered foals showed a transient increase in the insulin concentration 15 mins after birth which was not observed in the full term foals delivered by induction. Plasma glucose concentrations were maintained during the 2 h after birth in the absence of sucking in both the induced and the spontaneously delivered full term foals. Premature foals had significantly lower plasma glucose concentrations at birth than full term foals.(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of histamine, bradykinin, prostaglandins E1 and E2 and carrageenin as vascular permeability agents in the horse

The vascular leakage induced by histamine, bradykinin, serotonin and prostaglandin E1 and E2 was assessed. The test agents were injected intradermally into the shaved thoracic skin of horses and the vascular leakage estimated either semi-quantitatively by recording the diameter of the lesions or by measuring the actual volume of extravasated plasma in microliters using iodine-125-labelled human serum albumin (125I-HSA) as a marker in the blood plasma. Using the latter method, the vascular leakage induced by carrageenin and the effect of coadministered prostaglandins E1 and E2 upon the vascular leakage of both histamine and bradykinin were also investigated. No obvious lesions resulted when serotonin (10(-2) mol/l) was injected but histamine and bradykinin produced circular lesions which increased in diameter for approximately 30 min. The size of the lesions and volume of extravasated plasma was dose dependent. On a molar basis, bradykinin (10(-6) mol/l, 10(-5) mol/l) was more potent than histamine but they were equipotent at 10(-4) mol/l. The size of the lesions induced by carrageenin were independent of their anatomical location on the thorax. Except for the second hour, the hourly volume of vascular leakage increased until the fifth hour when the experiment was concluded. The maximum vascular leakage resulting from the injection of prostaglandin E1 or E2 (1, 10, 100 or 1000 ng) was 7 microliters but when co-administered with bradykinin (10(-6) mol/l), the volume of leaked plasma increased from 29 to 78 microliters. No synergy was observed when either prostaglandin was co-administered with histamine (10(-5) mol/l).     

Characterisation of equine T helper cells: demonstration of Th1- and Th2-like cells in long-term equine T-cell cultures

The aim of this study was to characterise CD4+T-cells in equines, as these cells are pivotal in establishing immune responses or regulating established ones. Peripheral blood mononuclear cells from a pony immunised with ovalbumin were cultured in vitro in the presence of the specific antigen and autologous antigen presenting cells. During the antigen starvation phase, cells were maintained on recombinant equine IL-2. After 35 days of culture, most of the cells were CD4+, CD8-and sIg-. Cells proliferated specifically in the presence of antigen, as tested on day 42 of culture. These cells were analysed by in-situ hybridisation to detect m RNA for IL-2 and IL-4, the presence of which suggested the existence of of Th1- and Th2-like cells.     

Characteristics of Gas Generation (NH3, CH4, N2O, CO2, H2O) From Horse Manure Added to Different Bedding Materials Used in Deep Litter Bedding Systems

The aim of this study was to analyze the influence of horse manure added to different bedding materials on the generation of gases (ammonia (NH₃), nitrous oxide, carbon dioxide, methane, water vapor) from deep litter bedding under standardized laboratory conditions. Two different types of straw (wheat and rye) and wood shavings were analyzed. The deep litter (substrate) was made of 25 kg of the respective bedding material, 60 kg horse feces, and 60 L ammonium chloride solution (urea), and spread out in identical chambers over 19 days (n = 3). On days 1, 8, 15, and 19, total nitrogen, total carbon, and dry matter content of the substrate, as well as the pH in 500-g samples, were measured along with. At the end of each test period, the nitrite nitrogen, nitrate nitrogen, and ammonium nitrogen contents of the leachate were analyzed. The wheat straw substrate emitted the highest concentration of NH₃ (4.31 mg/m³; P < .0001) and the wood shavings substrate emitted the lowest (1.73 mg/m³; P < .0001); the rye straw substrate generated 3.05 mg/m³. In addition, significant differences occurred during days 1 to 3 with respect to the generation of the gases NH₃, methane, nitrous oxide, carbon dioxide, and water vapor, and after the opening of the chamber on day 15. The nitrogen losses through the leachate occurred mainly in the form of nitrate, where the leachate from the wheat straw substrate had a significantly higher amount of nitrate nitrogen (44.56 mg) as compared with the leachates of the rye straw (14.49 mg; P ≤ .0001) and the wood shaving substrates (22.62 mg; P = .0010).