Lymphosarcoma in a boar

A 14-month-old Yorkshire boar was examined. In the abdomen, two big tumour masses were found in the intestines. In addition, pale nodules occurred in the liver, kidneys, in and upon the spleen, in the wall of the heart and in the testicles. By immunohistochemistry tumour cells were positive for CD3, but negative for B-lymphocyte antigen and CD79. From these findings it was concluded that the boar was suffering from multicentric lymphosarcoma probably of T-cell origin.     

Evaluation of three serum i-ELISAs using monoclonal antibodies and protein G as peroxidase conjugate for the diagnosis of bovine brucellosis

Three i-ELISAs using LPS, the immunodominant component of Brucella abortus, were developed with three different conjugates: monoclonal antibodies 1C8 (anti-bovine IgG(1)) and 3H3 (mainly specific for bovine IgG(2) but also reacting with IgG(1)) and protein G (reacts with both bovine IgG subclasses). Using a cut-off value of 2.5U/ml, the i-ELISA with 3H3 as conjugate had a specificity (95% CI: 98.32-99.63%) that was significantly higher than the same assay with 1C8 (95% CI: 96.08-98.26%) or PG (95% CI: 95.83-98.09%). In areas where false positive serological reactions (FPSR) were common, the specificity of the i-ELISAs decreased significantly. The specificity of the i-ELISAs increased with the age of the animals tested, irrespective of the conjugate. The specificity of the i-ELISAs and traditional tests was also examined using sera from animals infected per os with bacteria bearing LPS similar to the Brucella LPS. It appeared that Yersinia enterocolitica O:9, Xanthomonas maltophilia and Salmonella urbana infections induced FPSR both in the i-ELISAs and in the traditional tests, but the 3H3 assay was significantly less prone to produce false positive reactions than the 1C8 and PG assays. The i-ELISAs were more sensitive, allowed earlier detection, and were more persistent than the traditional serological tests both in experimentally and naturally Brucella-infected animals. Weekly i-ELISA monitoring of experimentally infected pregnant heifers (previously vaccinated or not) allowed a prediction of abortion. Furthermore, the 1C8 assay showed significantly higher titres irrespective of day post-infection and vaccination status. The accuracy of the assay could be improved by making use of additional information (e.g. animal age or conjugate) and by selecting appropriate cut-off points on the basis of the prevailing epidemiological situation. The i-ELISAs appear an appropriate choice in order to maintain an official brucellosis-free status because of their sensitivity, early detection and long persistence and, for the same reasons, seem especially valuable for the detection of latent carriers (i.e. animals classified negative by classical serological tests) among imported animals.     

Quantitative phenotyping of grey leaf spot disease in maize using real-time PCR

Grey leaf spot is an important maize foliar disease caused by the fungal pathogens Cercospora zeae-maydis and Cercospora zeina. Although methods exist to detect these Cercospora species in maize, current techniques do not allow quantification of the fungi in planta. We developed a real-time SYBR® Green PCR assay for quantification of grey leaf spot disease in maize based on the amplification of a fragment of a cytochrome P450 reductase (cpr1) gene. In planta fungal DNA content was normalised to a maize glutathione S-transferase III gene (gst3) to yield values of ng Cercospora DNA/mg maize DNA. The assay was specific to the two Cercospora spp., and we observed no amplification of the cpr1 fragment in non-target maize leaf pathogens or saprophytes. The assay was employed to quantify C. zeina in glasshouse inoculated maize plants and grey leaf spot infected field plants of resistant and susceptible maize lines. In both instances, C. zeina DNA content correlated with symptomatic leaf lesion area, and the susceptible maize line contained significantly more C. zeina DNA than the resistant line. Sequence differences between the C. zeina and C. zeae-maydis cpr1 amplicons enabled us to perform melt curve analyses to identify the Cercospora species causing grey leaf spot at a particular location. This assay has application in the early detection and quantification of Cercospora spp., both of which are important tools in grey leaf spot disease management and maize breeding programmes.     

Pretreatment mitochondrial priming correlates with clinical response to cytotoxic chemotherapy

Cytotoxic chemotherapy targets elements common to all nucleated human cells, such as DNA and microtubules, yet it selectively kills tumor cells. Here we show that clinical response to these drugs correlates with, and may be partially governed by, the pretreatment proximity of tumor cell mitochondria to the apoptotic threshold, a property called mitochondrial priming. We used BH3 profiling to measure priming in tumor cells from patients with multiple myeloma, acute myelogenous and lymphoblastic leukemia, and ovarian cancer. This assay measures mitochondrial response to peptides derived from proapoptotic BH3 domains of proteins critical for death signaling to mitochondria. Patients with highly primed cancers exhibited superior clinical response to chemotherapy. In contrast, chemoresistant cancers and normal tissues were poorly primed. Manipulation of mitochondrial priming might enhance the efficacy of cytotoxic agents.     

Functional Characterization of a New GH107 Endo-α-(1,4)-Fucoidanase from the Marine Bacterium Formosa haliotis

Fucoidans from brown macroalgae are sulfated fucose-rich polysaccharides, that have several beneficial biological activities, including anti-inflammatory and anti-tumor effects. Controlled enzymatic depolymerization of the fucoidan backbone can help produce homogeneous, defined fucoidan products for structure-function research and pharmaceutical uses. However, only a few endo-fucoidanases have been described. This article reports the genome-based discovery, recombinant expression in Escherichia coli, stabilization, and functional characterization of a new bacterial endo-α-(1,4)-fucoidanase, Fhf1, from Formosa haliotis. Fhf1 catalyzes the cleavage of α-(1,4)-glycosidic linkages in fucoidans built of alternating α-(1,3)-/α-(1,4)-linked l-fucopyranosyl sulfated at C2. The native Fhf1 is 1120 amino acids long and belongs to glycoside hydrolase (GH) family 107. Deletion of the signal peptide and a 470 amino acid long C-terminal stretch led to the recombinant expression of a robust, minimized enzyme, Fhf1Δ470 (71 kDa). Fhf1Δ470 has optimal activity at pH 8, 37–40 °C, can tolerate up to 500 mM NaCl, and requires the presence of divalent cations, either Ca²⁺, Mn²⁺, Zn²⁺ or Ni²⁺, for maximal activity. This new enzyme has the potential to serve the need for controlled enzymatic fucoidan depolymerization to produce bioactive sulfated fucoidan oligomers.     

An evaluation of fish health‐management practices and occupational health hazards associated with Pangasius catfish (Pangasianodon hypophthalmus) aquaculture in the Mekong Delta,Vietnam

This study aimed to evaluate the current status on the use of probiotics, disinfectants and antimicrobials in hatcheries, nurseries and grow‐out farms producing Pangasius catfish (Pangasianodon hypophthalmus) in the Mekong Delta, Vietnam. Semi‐structured interviews were conducted with 83 aquaculture enterprises (15 hatcheries, 32 nurseries and 36 grow‐out farms). Farmers reported use of a total of 24 different antimicrobials, e.g. for treatment of bacillary necrosis and motile aeromonad septicaemia, and a variety of disinfectants, probiotics and nutritional supplements. In contrast to small‐scale farmers, all large‐scale grow‐out farmers studied were certified and therefore had higher levels of formal education and specialized aquaculture training to diagnose and treat diseases. All farmers prepared their own medicated feed with a high risk of treatment failure, negative environmental impact from released antimicrobials and resistance development. Small‐scale farmers were at particular occupational health risks when handling antimicrobials and other chemicals, e.g. mixing medicated feed with bare hands. There is an urgent need to improve knowledge and use innovative approaches, e.g. private‐public partnerships, to assure a prudent use of chemicals, to improve capacity and access to disease diagnosis, particularly for small‐scale grow‐out farmers and nurseries. Efforts to control use of antimicrobials in aquaculture should be coordinated with the livestock and human health sectors taking an One‐Health approach.