Histopathological findings,phenotyping of inflammatory cells,and expression of markers of nitritative injury in joint tissue samples from calves after vaccination and intraarticular challenge with Mycoplasma bovis strain 1067

Background

The pathogenesis of caseonecrotic lesions developing in lungs and joints of calves infected with Mycoplasma bovis is not clear and attempts to prevent M. bovis-induced disease by vaccines have been largely unsuccessful. In this investigation, joint samples from 4 calves, i.e. 2 vaccinated and 2 non-vaccinated, of a vaccination experiment with intraarticular challenge were examined. The aim was to characterize the histopathological findings, the phenotypes of inflammatory cells, the expression of class II major histocompatibility complex (MHC class II) molecules, and the expression of markers for nitritative stress, i.e. inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT), in synovial membrane samples from these calves. Furthermore, the samples were examined for M. bovis antigens including variable surface protein (Vsp) antigens and M. bovis organisms by cultivation techniques.

Results

The inoculated joints of all 4 calves had caseonecrotic and inflammatory lesions. Necrotic foci were demarcated by phagocytic cells, i.e. macrophages and neutrophilic granulocytes, and by T and B lymphocytes. The presence of M. bovis antigens in necrotic tissue lesions was associated with expression of iNOS and NT by macrophages. Only single macrophages demarcating the necrotic foci were positive for MHC class II. Microbiological results revealed that M. bovis had spread to approximately 27% of the non-inoculated joints. Differences in extent or severity between the lesions in samples from vaccinated and non-vaccinated animals were not seen.

Conclusions

The results suggest that nitritative injury, as in pneumonic lung tissue of M. bovis-infected calves, is involved in the development of caseonecrotic joint lesions. Only single macrophages were positive for MHC class II indicating down-regulation of antigen-presenting mechanisms possibly caused by local production of iNOS and NO by infiltrating macrophages.     

Gene-expression profiling of calves 6 and 9?months after inoculation with Mycobacterium avium subspecies paratuberculosis

Early detection of Johne’s disease (JD) caused by Mycobacterium avium subspecies paratuberculosis (MAP) is essential to reduce transmission; consequently, new diagnostic techniques and approaches to detect MAP or markers of early MAP infection are being explored. The objective was to identify biomarkers associated with MAP infection at 6 and 9 months after oral inoculation. Therefore, gene expression analysis was done using whole blood cells obtained from MAP-infected calves. All MAP-inoculated calves had a cell-mediated immune response (IFN-γ) to Johnin PPD specific antigens, and 60% had an antibody response to MAP antigens. Gene expression analysis at 6 months after inoculation revealed downregulation of chemoattractants, namely neutrophil beta-defensin-9 like peptide (BNBD9-Like), S100 calcium binding protein A9 (s100A9) and G protein coupled receptor 77 (GPR77) or C5a anaphylatoxin chemotactic receptor (C5a2). Furthermore, BOLA/MHC-1 intracellular antigen presentation gene was downregulated 9 months after inoculation. In parallel, qPCR experiments to evaluate the robustness of some differentially expressed genes revealed consistent downregulation of BOLA/MHC-I, BNBD9-Like and upregulation of CD46 at 3, 6, 9, 12, and 15 months after inoculation. In conclusion, measuring the expression of these genes has potential for implementation in a diagnostic tool for the early detection of MAP infection.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0096-5) contains supplementary material, which is available to authorized users.     

Detection of RHDV strains in the Iberian hare (Lepus granatensis): earliest evidence of rabbit lagovirus cross-species infection

Rabbit hemorrhagic disease virus (RHDV) is a highly lethal Lagovirus, family Caliciviridae, that threatens European rabbits (Oryctolagus cuniculus). Although a related virus severely affects hares, cross-species infection was only recently described for new variant RHDV in Cape hares (Lepus capensis mediterraneus). We sequenced two strains from dead Iberian hares (Lepus granatensis) collected in the 1990s in Portugal. Clinical signs were compatible with a Lagovirus infection. Phylogenetic analysis of the complete capsid gene positioned them in the RHDV genogroup that circulated on the Iberian Peninsula at that time. This is the earliest evidence of RHDV affecting a species other than European rabbits.     

牛A-FABP与SREBP1基因的组织表达规律研究

A-FABP(脂肪细胞型脂肪酸结合蛋白)和SREBP1(固醇调节元件结合蛋白)是动物体内参与脂肪沉积和脂质合成的重要基因。为了研究这两种基因在牛组织中的表达规律,研究利用qRT-PCR技术检测A-FABP和SREBP1在荷斯坦牛13种组织中表达水平,并进一步比较了这两个基因在秦川牛和雪龙黑牛脂肪、肌肉和肝脏的组织中表达差异。研究结果表明A-FABP基因在脂肪组织中的表达水平远远高于其他组织,SREBP1基因在各组织中均有表达,脂肪组织的相对表达量最高。A-FABP基因在雪龙黑牛肌肉和肝脏组织中的表达量显著高于秦川牛的肌肉和肝脏(P0.05),而在脂肪组织中,秦川牛和雪龙黑牛该基因表达量无显著差异(P0.05)。SREBP1基因在雪龙黑牛肌肉和肝脏组织中的表达量显著高于秦川牛的肌肉和肝脏(P0.05),而在脂肪组织中,秦川牛表达量显著高于雪龙黑牛(P0.05)。由于A-FABP和SREBP1在脂肪中表达量最高,且它们的表达量在脂肪沉积能力不同的秦川牛和雪龙黑牛肌肉和肝脏组织中存在显著差异,故推断这两种基因在牛脂肪组织的脂质代谢过程中发挥重要作用,对脂肪的沉积和大理石花纹牛肉的形成起到一定的调控作用。     

南方水田农用化学品投入水平及分析——以湖北湖南农户调查为例

利用农户调查及统计资料对南方水田地区农用化学品投入进行了实证分析,主要揭示了农户过量施用化肥和农药的情形以及目前有关农用化学品数据收集及计算中存在的问题。建议完善和实施有关化学品使用的普查、监测制度体系及相关政策。     

Quantum simulation of frustrated classical magnetism in triangular optical lattices

Magnetism plays a key role in modern technology and stimulates research in several branches of condensed matter physics. Although the theory of classical magnetism is well developed, the demonstration of a widely tunable experimental system has remained an elusive goal. Here, we present the realization of a large-scale simulator for classical magnetism on a triangular lattice by exploiting the particular properties of a quantum system. We use the motional degrees of freedom of atoms trapped in an optical lattice to simulate a large variety of magnetic phases: ferromagnetic, antiferromagnetic, and even frustrated spin configurations. A rich phase diagram is revealed with different types of phase transitions. Our results provide a route to study highly debated phases like spin-liquids as well as the dynamics of quantum phase transitions.     

Saturation of the southern ocean CO2 sink due to recent climate change

Based on observed atmospheric carbon dioxide (CO2) concentration and an inverse method, we estimate that the Southern Ocean sink of CO2 has weakened between 1981 and 2004 by 0.08 petagrams of carbon per year per decade relative to the trend expected from the large increase in atmospheric CO2. We attribute this weakening to the observed increase in Southern Ocean winds resulting from human activities, which is projected to continue in the future. Consequences include a reduction of the efficiency of the Southern Ocean sink of CO2 in the short term (about 25 years) and possibly a higher level of stabilization of atmospheric CO2 on a multicentury time scale.     

Social networks and information access: Implications for agricultural extension in a rice farming community in northern Vietnam

Village communities are not homogeneous entities but a combination of complex networks of social relationships. Many factors such as ethnicity, gender, socio-economic status, and power relations determine one’s access to information and resources. Development workers’ inadequate understanding of local social networks, norms, and power relations may further the interests of better-off farmers and marginalize the poor. This paper explores how social networks function as assets for individuals and households in the rural areas of developing countries and influence access to information and benefits from research and development. A case study of such networks in Phieng Lieng village, in the northern mountains of Vietnam, provides evidence for the need for the efficient delivery of extension services and research and development interventions at the micro level. Lan Anh Hoang is a social scientist with a special interest in social networks and gender and power relations in rural areas. She is currently working on her PhD at the School of Development Studies, University of East Anglia (UK) on “Gender relations, household power hierarchies, and social norms in migration decision-making in rural Vietnam.” She was involved in the Mountain Agrarian Systems Program in Bac Kan Province from 1999 to 2002. Jean -Christophe Castella is a production systems agronomist from the Institut de Recherche pour le Développement (IRD, France). Between 1998 and 2003, he coordinated a joint research program on “comprehensive study of land use changes in northern Vietnam uplands” in partnership with the Vietnam Agricultural Science Institute (VASI, Hanoi, Vietnam) and the International Rice Research Institute (IRRI, Philippines). Paul Novosad was involved with the Mountain Agrarian Systems program from January to July 2002. He helped to synthesize the results of field research and also was involved in analyzing data related to social networks. Since fall 2002 he studies Public Administration and International Development at the Kennedy School of Government in the United States (Cambridge, Massachusetts).     

Neurosteroids: cytochrome P-450scc in rat brain

The steroid hormones corticosterone and testosterone are supplied to the central nervous system by endocrine glands, the adrenals and gonads. In contrast, the 3 beta-hydroxy-delta 5-derivatives of cholesterol, pregnenolone and dehydroepiandrosterone, accumulate in the rat brain through mechanisms independent of peripheral sources. Immunohistochemical studies have been performed with specific antibodies to bovine adrenal cytochrome P-450scc, which is involved in cholesterol side-chain cleavage and pregnenolone formation. The enzyme was localized in the white matter throughout the brain. Scarce clusters of cell bodies were also stained in the entorhinal and cingulate cortex and in the olfactory bulb. These observations strongly support the existence of "neurosteroids," which have been posited on the basis of biochemical, physiological, and behavioral studies.     

3种观赏草在自然失水胁迫下的生理变化与耐旱性关系

对斑叶芒(Miscanthus sinensis variegatus)、狼尾草(Pennisetum alopecuroides)、矮蒲苇(Cortaderia selloa-napumila)3种观赏草在干旱胁迫下的形态与生理变化进行研究,在为期19d的自然失水胁迫处理下,研究结果表明:随着干旱胁迫时间的延长,3种观赏草的游离脯氨酸、膜透性、丙二醛(MDA)的量不断增加,与枯叶率的增加呈显著正相关;斑叶芒和狼尾草叶片的SOD活性在干旱胁迫后期明显高于矮蒲苇;比较形态和生理指标后,认为狼尾草的耐旱性最强,斑叶芒次之,矮蒲苇对于干旱最敏感。