Mercury Concentration and Monomethylmercury Production in Sediment: Effect of Dredged Sediment Reuse on Bioconcentration for Ragworms

The effect of dredged sediment reuse on the production and bioconcentration of monomethylmercury (MMHg) was investigated by examining sediments and ragworms found in dredge material banks and surrounding sites in the Venice Lagoon, Italy. Total Hg concentrations in the surface 20 cm of sediments were higher in the banks than in the surrounding sites, but MMHg concentrations were similar, which suggests reduced MMHg production in the banks. Monomethylmercury content in ragworms was significantly lower (p?<?0.05) in the banks than in the surrounding sites. In pore water, concentrations of both sulfate and Fe decreased with depth in the upper 20 cm of the dredge banks. In contrast, sulfate concentrations were constant with depth and large amounts of dissolved Fe occurred in the upper 20 cm of sediments of surrounding sites. Continuous sulfate reduction and possible precipitation of iron sulfide may decrease the production and bioconcentration of MMHg in the dredge material banks compared to the surrounding sites. Overall, the production of MMHg in sediments and its bioconcentration in benthic organisms were connected to the process of sediment diagenesis of organic matter through the control of pore water and sediment geochemistry involving iron and sulfur.     

Does Biofloc Improve the Energy Distribution and Final Muscle Quality of Shrimp,Litopenaeus vannamei (Boone, 1883)?

In a 45‐d experiment, Litopenaeus vannamei was cultured in two treatments, biofloc technology or clear water recirculating aquaculture system, to evaluate the effect on growth and survival, energy balance, and texture of the marketable product. The experimental design consisted of 40 plastic tanks of 54 L (20 tanks per treatment), with a density of 140 organisms/m³ in each culture system. The final body weight, daily growth coefficient, and survival were significantly higher (P < 0.05) in biofloc technology (12.40 g, 5.0%g/d, and 87.1%, respectively) than in the clear water system (7.0 g, 1.4%g/d, and 74.2%). The retained energy and energy content of exuviae were significantly higher for shrimp in the biofloc technology (448.5 ± 36.4 and 22.4 ± 1.8 J/shrimp/d, respectively) than in clear water (246.3 ± 40.9 and 12.3 ± 2.0 J/shrimp/d, respectively). Routine metabolism was significantly higher for the clear water treatment (411.4 ± 123.8 J/shrimp/d). Shear force was higher in the biofloc technology, indicating greater muscle firmness; this matched the gel electrophoresis patterns of the proteins extracted from the muscle tissues. This suggests that biofloc technology could be used not only to improve growth and survival in L. vannamei but also to enhance the final product quality and acceptability in the market.     

Effect of environmental conditions on polychlorinated biphenyl transformations and bacterial communities in a river sediment

Purpose  

The aim of this study was to evaluate polychlorinated biphenyl (PCB) removal in relation to the associated bacterial community composition in Ohio River sediments (USA) using field and laboratory approaches.     

Langerhans cells facilitate epithelial DNA damage and squamous cell carcinoma

Polyaromatic hydrocarbons (PAHs) are prevalent, potent carcinogens, and 7,12-dimethylbenz[a]anthracene (DMBA) is a model PAH widely used to study tumorigenesis. Mice lacking Langerhans cells (LCs), a signatory epidermal dendritic cell (DC), are protected from cutaneous chemical carcinogenesis, independent of T cell immunity. Investigation of the underlying mechanism revealed that LC-deficient skin was relatively resistant to DMBA-induced DNA damage. LCs efficiently metabolized DMBA to DMBA-trans-3,4-diol, an intermediate proximal to oncogenic Hras mutation, and DMBA-treated LC-deficient skin contained significantly fewer Hras mutations. Moreover, DMBA-trans-3,4-diol application bypassed tumor resistance in LC-deficient mice. Additionally, the genotoxic impact of DMBA on human keratinocytes was significantly increased by prior incubation with human-derived LC. Thus, tissue-associated DC can enhance chemical carcinogenesis via PAH metabolism, highlighting the complex relation between immune cells and carcinogenesis.     

A case of an apparent infestation by Proisotoma spp. springtails (Collembola: Isotomidae) in a cat

This case report is presumed to be the first case of infestation of a cat by springtails which are small arthropods closely related to insects. The organisms, found by skin scrapings, were identified as Proisotoma spp. (Collembola: Isotomidae). The cat presented with dermatological lesions (itchy, furfuraceous dermatitis), and we speculate that they were due to this infestation. The pathogenic role of the Collembola was hypothesized because of the large number of organisms, the presence of eggs indicating an active reproduction cycle, the lack of other pathogens (fleas, mites or lice) and the clinical recovery accompanied by the disappearance of Collembola following treatment. The owner seemed to be affected by the infestation, because a few days after having purchased the cat, she developed a pruriginous papular dermatitis on the neck and the arms, which disappeared shortly after treatment of the kitten and a careful washing of all of its toys and other accoutrements.     

Comparison of two formulations of buprenorphine in cats administered by the oral transmucosal route

This randomised, blinded, cross-over study investigated the ease of oral transmucosal administration of two formulations of buprenorphine using glucose as a control in 12 cats. The cats received three treatments: buprenorphine multi-dose, buprenorphine and the equivalent volume of glucose 5%. Ease of treatment administration, observation of swallowing, changes in pupil size, sedation, salivation, vomiting, behaviour and food intake were assessed. The data were analysed using MLwiN and multi-level modelling. Ease of administration of buprenorphine multi-dose was statistically different from glucose (P <0.001), and the administration of all treatments became easier over the study periods. Swallowing was not statistically different between groups (P >0.05). Mydriasis was evident after the administration of both formulations of buprenorphine. Sedation, salivation, vomiting, behavioural changes or in-appetence were not observed after any treatment. Cats tolerated oral transmucosal administration of glucose better than buprenorphine multi-dose, while buprenorphine administration was tolerated as well as glucose.     

Modulation of innate immunity in chickens induced by in vivo administration of baculovirus

Baculoviruses stimulate cytokine production in mammalian cells. They induce a strong innate immune response in animals and have adjuvant properties. The purpose of this work was to study the in vivo effect of baculovirus on chicken innate immune response. SPF chickens were inoculated intravenously with Autographa californica nuclear polyhedrosis virus (BV). Three hours later, chickens were bled, euthanized and their spleen, duodenum and cecal tonsils were excised in order to take samples for RNA extraction and real time PCR, and to isolate lymphocytes, which were stained and analyzed by flow cytometry. The results obtained showed that baculovirus inoculation up-regulates the expression of IFN-γ, IL-6 and LITAF in spleen cells. This result (IFN-γ) correlated with that obtained by ELISA which showed a very strong increase of IFN-γ in chicken plasma. Flow cytometry analysis revealed that BV inoculation induced in spleen an increase in the percentage of monocyte/macrophage population together with an increase in CD3(+)CD4(+) T lymphocytes. On the other hand, BV inoculation decreased the percentage of CD3(+)CD4(+) T lymphocytes and increased the percentage of NK cells in cecal tonsils. However, intraepithelial lymphocytes of the gut did not show differences between BV and control treated animals. Even though further studies in order to understand the mechanisms by which BVs affect the avian immune response are needed, results obtained in the present work demonstrate the ability of BVs to stimulate the innate immunity in chickens, modifying the expression pattern of related genes and the profile of the immune cells involved.     

Virus-like particles: The new frontier of vaccines for animal viral infections

Vaccination continues to be the main approach to protect animals from infectious diseases. Until recently, all licensed vaccines were developed using conventional technologies. Subunit vaccines are, however, gaining attention from researchers in the field of veterinary vaccinology, and among these, virus-like particles (VLPs) represent one of the most appealing approaches. VLPs are robust protein cages in the nanometer range that mimic the overall structure of the native virions but lack the viral genome. They are often antigenically indistinguishable from the virus from which they were derived and present important advantages in terms of safety. VLPs can stimulate strong humoral and cellular immune responses and have been shown to exhibit self-adjuvanting abilities. In addition to their suitability as a vaccine for the homologous virus from which they are derived, VLPs can also be used as vectors for the multimeric presentation of foreign antigens. VLPs have therefore shown dramatic effectiveness as candidate vaccines. Here, we review the current status of VLPs as a vaccine technology in the veterinary field, and discuss the potential advantages and challenges of this technology.