应用HRP—SPA—ELISA检测猪瘟病毒抗体的试验研究

应用猪瘟兔化弱毒PEG沉淀抗原、HRP—SPA建立了HRP—SPA—ELISA检测猪瘟病毒抗体的方法。通过对5份阴性血清和32头仔猪注苗前及注苗后不同时期256份系列血清的检测以及阻断试验,证明本法具有较高的敏感性和特异性。猪瘟抗体ELISA效价与兔体中和试验效价比较,二者呈显著的正相关(r=0.8072)。对32头仔猪系列血清的检测结果表明,免疫母猪(配种前45d左右注苗)所生的30～40日龄未注苗仔猪的母源抗体水平不很高,有1/3在阴性范围内,注苗后15d,ELISA抗体开始上升,90d达峰值;90～120d大部分猪的抗体水平迅速下跌到略高于60d时的抗体水平上,保持稳定约2个月左右,但也有一少部分猪90d后抗体水平下跌缓慢,一直保持相当高的水平。     

樱桃谷鸭大肠杆菌病的诊治

鸭大肠杆菌病是由致病性大肠杆菌引起的多病型疾病的总称。临床病型众多,其中以雏鸭或小鸭败血症和产蛋母鸭的卵黄性腹膜炎(蛋子瘟)危害最为严重,该病是目前对养鸭业危害较大的传染病。2012年3月,盘锦市某大型养鸭场饲养2000多只樱桃谷鸭,从186日龄开始陆续发病,主要表现为产蛋率迅速下降,病鸭精神萎顿,食欲减退,下痢,发病后期病鸭的腹部膨大、下垂,病死率约为4%。通过临床观察、病理剖检及实验室检查,确诊为鸭大肠杆菌病。根据药敏试验结果,选用极度敏感的丁胺卡那霉素治疗并采取综合性措施,迅速控制了病情。     

Identification of African swine fever virus genomic DNAs in wild boar habitats within outbreak regions in South Korea

An African swine fever (ASF) outbreak in wild boars was first reported on October 2, 2019, in South Korea. Since then, additional cases were reported in South Korea''s border areas. We here report the identification of ASF virus (ASFV) DNAs from two out of eight environmental abiotic matter samples collected from areas where ASF-positive wild boar carcasses were found. Comparative genomic investigations suggested that the contaminating ASFV DNAs originated from the wild boar whose carcass had been found near the positive sample sites. This is the first report on the identification of ASF viral material in wild boar habitats.     

从流域坝系建设看淤地坝在水土保持工作中的作用——以宁夏海原县园河流域为例

在流域坝系建设中,淤地坝的作用非常明显,主要有:拦泥保土,有效减少了入黄泥沙;淤地造田,提高粮食产量;提高黄土丘陵区水资源利用效率,解决了农民生活生产用水;增加农民收入,发展了农村经济;促进退耕,改善了生态环境;利于区域防洪减灾,保护沟道下游生产安全;以坝代桥,改善了交通条件.淤地坝是黄土高原防治水土流失的重要措施,提出淤地坝在坝系建设中的不足和改进意见.     

王行宽教授“甘温除热法”治疗难治性内伤发热医案二则

王行宽教授认为治疗难治性内伤发热,甘温除热当师其法且活其用,即甘温除热法“无须拘泥于补中益气汤”,因“补中益气汤”侧重脾气虚发热之证,难治性内伤发热病机复杂,常兼有气血不足,营卫不和,肝胆失疏等证,临床上运用当归补血汤、桂枝汤、小柴胡汤的复方治疗方可起到明显的疗效。     

The reduction of CSFV transmission to untreated pigs by the pestivirus inhibitor BPIP: A proof of concept

5-[(4-Bromophenyl)methyl]-2-phenyl-5H-imidazo[4,5-c]pyridine (BPIP) is a representative molecule of a novel class of highly active in vitro inhibitors of the replication of Classical swine fever virus (CSFV). We recently demonstrated in a proof of concept study that the molecule has a marked effect on viral replication in CSFV-infected pigs. Here, the effect of antiviral treatment on virus transmission to untreated sentinel pigs was studied. Therefore, BPIP-treated pigs (n = 4), intra-muscularly infected with CSFV, were placed into contact with untreated sentinel pigs (n = 4). Efficient transmission of CSFV from four untreated seeder pigs to four untreated sentinels was observed. In contrast, only two out of four sentinel animals in contact with BPIP-treated seeder animals developed a short transient infection, of which one was likely the result of sentinel to sentinel transmission. A significant lower viral genome load was measured in tonsils of sentinels in contact with BPIP-treated seeder animals compared to the positive control group (p = 0.015). Although no significant difference (p = 0.126) in the time of onset of viraemia could be detected between the groups of contact animals, a tendency towards the reduction of virus transmission was observed. Since sentinel animals were left untreated in this exploratory trial, the study can be regarded as a worst case scenario and gives therefore an underestimation of the potential efficacy of the activity of BPIP on virus transmission.     

非洲猪瘟病毒传播方式及控制措施

非洲猪瘟(African swine fever,ASF)是由非洲猪瘟病毒(African swine fever virus,ASFV)引起的一种急性、热性、高度传染性疫病,感染猪以发热和全身性出血为主要特征,病程短、病死率高。非洲猪瘟主要流行于非洲国家,随后相继传入西欧、南美洲、东欧,以及亚洲国家,对全球养猪业、食品安全和猪及其产品国际贸易产生了严重危害和深远影响。现结合参考文献和我国非洲猪瘟发生、控制情况,分析了非洲猪瘟病毒传播动力学、传播方式,提出防控非洲猪瘟的主要措施。     

不同放牧强度对拉萨河谷温性草原主要植物生态位及种间联结的影响

为了探明不同放牧强度如何影响物种的生态位和种间联结,本研究设置三种放牧强度,采用"Levins"方法计算物种的生态位宽度和生态位重叠值,以及使用方差比率法(VR)、卡方检验、联结系数(association coefficient,AC)和Ochiai(OI)指数分析了种间联结性.结果表明,中度放牧和禁牧增加了优势种的...     

Antibody-mediated enhancement of disease in feline infectious peritonitis: Comparisons with dengue hemorrhagic fever

Non-immune kittens passively immunized with feline serum containing high-titered antibodies reactive with feline infectious peritonitis virus (FIPV) developed a more rapid disease after FIPV challenge than did kittens pretreated with FIPV antibody-negative serum. Antibody-sensitized, FIPV challenged—kittens developed earlier clinical signs (including pyrexia, icterus, and thrombocytopenia) and died more rapidly than did non-sensitized, FIPV-challenged kittens. Mean survival time in sensitized kittens was significantly (P < 0.05) reduced compared to non-sensitized kittens (mean ± SEM, 10.0 ± 0.6 days vs. 28.8 ± 8.3 days, respectively). Lesions induced included fibrinous peritonitis, disseminated pyogranulomatous inflammation and necrotizing phlebitis and periphlebitis. FIPV antigen, immunoglobulin G, complement (C3) and fibrinogen were demonstrated in lesions by immunofluorescence microscopy.The pathogenesis of dengue hemorrhagic fever (DHF) in persons bears striking resemblance to that of FIP in experimental kittens. In both FIP and DHF, non-neutralizing antibody may promote acute disease by enhancement of virus infection in mononuclear phagocytes or by formation of immune complexes, activation of complement and secondary vascular disturbances.     

伊犁河谷山地北坡土壤特性及植被群落多样性垂直分布格局

基于对伊犁河谷山地北坡垂直地带植被多样性和土壤生境的调查分析数据,采用Pearson相关系数法、主成分法和DCA排序法分析了物种多样性指数与环境因子之间的关系。结果表明:根据其植被带和土壤带沿不同海拔将其分为针叶林、山地草原、落叶阔叶林和荒漠草原;其总的物种丰富度和Simpson指数与海拔呈现先升高后降低,再升高的格局,不同海拔植被群落丰富度指数之间差异均显著(p0.05),Shannon-Wiener指数随海拔的增加呈先增加后降低的趋势,Pielou均匀度指数随海拔的增加呈先降低后增加,然后降低的格局。犁河谷山地北坡土壤有机质和有效氮含量随海拔的增加而增加的趋势,基本表现为针叶林山地草原落叶阔叶林荒漠草原,其中不同海拔植被群落土壤有机质含量之间差异均显著(p0.05),土壤有效磷含量没有明显的垂直变化规律,土壤有效钾含量随海拔的增加呈先增加后降低的趋势,基本表现为山地草原针叶林落叶阔叶林荒漠草原。犁河谷山地北坡土壤pH值随海拔的增加而降低的趋势,基本表现为荒漠草原山地草原落叶阔叶林针叶林,土壤电导率、全盐和总盐含量均随海拔的增加呈先增加后降低的格局,基本表现为山地草原落叶阔叶林荒漠草原针叶林。主成分的结果分析表明,第一主成分负荷值最高的分别为土壤全盐、总盐、电导率,可称为土壤盐分因子;第二主成分负荷值最高的分别为土壤有效氮、有机质和pH值,可称为保肥、供肥因子。DCA排序结果表明,沿着DCA第一轴,随着海拔逐渐降低,土壤有机质、有效氮和有效钾等土壤养分的含量逐渐下降,而pH值和电导率逐渐上升;沿着DCA第二轴,随着海拔逐渐降低,土壤总盐和全盐含量逐渐增加,而土壤有效磷含量却逐渐降低。由此可知,犁河谷山地北坡植物群落多样性的垂直分布格局是由海拔为主的多种环境因子综合作用的结果,而土壤养分和盐分随海拔的变化与植被带不尽一致,可能它们之间的同步变化存在一定的滞后期。