Hepatitis E in southern Vietnam: Seroepidemiology in humans and molecular epidemiology in pigs

Viral pathogens account for a significant proportion of the burden of emerging infectious diseases in humans. The Wellcome Trust‐Vietnamese Initiative on Zoonotic Infections (WT‐VIZIONS) is aiming to understand the circulation of viral zoonotic pathogens in animals that pose a potential risk to human health. Evidence suggests that human exposure and infections with hepatitis E virus (HEV) genotypes (GT) 3 and 4 results from zoonotic transmission. Hypothesising that HEV GT3 and GT4 are circulating in the Vietnamese pig population and can be transmitted to humans, we aimed to estimate the seroprevalence of HEV exposure in a population of farmers and the general population. We additionally performed sequence analysis of HEV in pig populations in the same region to address knowledge gaps regarding HEV circulation and to evaluate if pigs were a potential source of HEV exposure. We found a high prevalence of HEV GT3 viral RNA in pigs (19.1% in faecal samples and 8.2% in rectal swabs) and a high HEV seroprevalence in pig farmers (16.0%) and a hospital‐attending population (31.7%) in southern Vietnam. The hospital population was recruited as a general‐population proxy even though this particular population subgroup may introduce bias. The detection of HEV RNA in pigs indicates that HEV may be a zoonotic disease risk in this location, although a larger sample size is required to infer an association between HEV positivity in pigs and seroprevalence in humans.     

A combined bovine herpesvirus 1 gB-gD DNA vaccine induces immune response in mice

Although DNA vaccines have several advantages over conventional vaccines, antibody production and protection are often not adequate, particularly in single plasmid vaccine formulations. Here we assessed the potential for a combined vaccine based on plasmids encoding the membrane-anchored or secreted forms of bovine herpesvirus type 1 (BHV-1) glycoprotein B and D (gB and gD) to induce neutralizing and cell mediated immune responses in mice. Animals were injected by intramuscular, subcutaneous and intranasal routes. Mice immunized with the combined vaccine containing the secreted forms of BHV-1 glycoproteins developed higher titers of anti-BHV-1 neutralizing antibodies, compared to wild type gB/gD combined plasmids and to single plasmid injected groups. Cellular immunity was also developed in mice immunized with combined vaccines, whereas low or no response were observed in single plasmid injected animals. The data suggest the potential use of this combined vaccine in in vivo trials of calves, in order to evaluate its protective efficacy.     

Curvilinear, three-dimensional motion of chromatin domains and nucleoli in neuronal interphase nuclei

The term "nuclear rotation" refers to a motion of nucleoli within interphase nuclei of several cell types. No mechanism or function has been ascribed to this phenomenon, and it was unknown whether nuclear structures in addition to nucleoli participate in this motion. Moreover, it was unclear whether nuclear rotation occurs independent of concurrent motion of juxtanuclear cytoplasm. The work reported here presents quantitative evidence, for three-dimensional intranuclear, tandem motion of fluorescently labeled chromatin domains associated with nucleoli and those remote from nucleoli. The results show that such motion is curvilinear, that it is not restricted to nucleoli, and, moreover, that it occurs independently of motion of juxtanuclear, cytoplasmic structures. These results suggest that this motion represents karyoplasmic streaming and its function is to transpose to nuclear pores those chromatin domains actively transcribed.     

Impact of Past Mining Activity on the Quality of Water and Soil in the High Moulouya Valley (Morocco)

Physical and chemical properties and the total content of potentially toxic metals (PTMs) in waters and soils were studied from the High Moulouya Valley (Morocco) in order to assess the impact of the past mining activity on their quality and to lay the foundations of a potential reclamation of the area. Surface water and groundwater samples were collected from the Moulouya River and mine pit lakes; tailings and soils were sampled inside and outside the mine sites of Zeïda, Mibladen, and Aouli. Both waters and soils were alkaline, due to the limestone environment, and contained Pb and Zn as main metallic contaminants. Pollution levels were highest within the Mibladen mining site, and soil pollution was mainly restricted to the areas where activities of metal concentration were carried out. Tailings and soils from these areas besides Pb and Zn were also polluted by As, Cd, and Cu showing clay fraction highly enriched in metal contaminants. At the time of study, all soils and wastes (including the highly polluted tailings) were in advanced stage of spontaneous herbaceous and arbustive revegetation. It is concluded that, in the High Moulouya Valley, the processes governing PTM transfer from the element-rich sites to the nearby environment are strongly influenced by pH, carbonate content, and semi-arid climate reducing metal mobility from the mining waste impoundments by dissolution. The transfer by wind and water erosion of metal-enriched fine waste particles is likely to be a much more important vector for metal dispersion. In this perspective, among a range of land remediation techniques available, natural and oriented revegetation could represent a low-cost and possible permanent solution.     

Size fractions of organic matter pools influence their stability: Application of the Rock-Eval® analysis to beech forest soils

Soil organic matter (SOM) is a complex heterogeneous mixture formed through decomposition and organo-mineral interactions, and characterization of its composition and biogeochemical stability is challenging. From this perspective, Rock-Eval^® is a rapid and efficient thermal analytical method that combines the quantitative and qualitative information of SOM, including several parameters related to thermal stability. This approach has already been used to monitor changes in organic matter (OM) properties at the landscape, cropland, and soil profile scales. This study was aimed to assess the stability of SOM pools by characterizing the grain size fractions from forest litters and topsoils using Rock-Eval^® thermal analysis. Litter (organic) and topsoil samples were collected from a beech forest in Normandy (France), whose management in the last 200 years has been documented. Fractionation by wet sieving was used to separate large debris (> 2 000 μm) and coarse (200-2 000 μm) and fine particulate OM (POM) (50-200 μm) in the organic samples as well as coarse (200-2 000 μm), medium (50-200 μm), and fine (< 50 μm) fractions of the topsoil samples. Rock-Eval^® was able to provide thermal parameters sensitive enough to study fine-scale soil processes. In the organic layers, quantitative and qualitative changes were explained by the progressive decomposition of labile organic compounds from plant debris to the finest organic particles. Meanwhile, the grain size fractions of topsoils presented different characteristics. The coarse organo-mineral fractions showed higher C contents, albeit with a different composition, higher thermal stability, and greater decomposition degree than the plant debris forming the organic layer. These results are consistent with those of previous studies that microbial activity is more effective in this fraction. The finest fractions of topsoils showed low C contents, the highest thermal stability, and low decomposition degree, which can be explained by the stronger interactions with the mineral matrix. Therefore, it is suggested that the dynamics of OM in the different size fractions be interpreted in the light of a plant-microbe-soil continuum. Finally, three distinct thermostable C pools were highlighted through the grain size heterogeneity of SOM:free coarse OM (large debris and coarse and fine particles), weakly protected OM in (bio)aggregates (coarse fraction of topsoil), and stabilized OM in the fine fractions of topsoil, which resulted from the interactions within organo-mineral complexes. Therefore, Rock-Eval^® thermal parameters can be used to empirically illustrate the conceptual models emphasizing the roles of drivers played by the gradual decomposition and protection of the most thermally labile organic constituents.     

Population pharmacokinetic modelling and simulation of single and multiple dose administration of meloxicam in cats

Lehr, T., Narbe, R., Jöns, O., Kloft, C., Staab, A. Population pharmacokinetic modelling and simulation of single and multiple dose administration of meloxicam in cats. J. vet. Pharmacol. Therap. 33 , 277–286. The objectives of these investigations were: first, to describe the pharmacokinetic properties of meloxicam in cats following single and multiple oral administration and secondly, to simulate different oral dosage regimes for meloxicam in cats after multiple dose administration to illustrate and evaluate those dosage regimes for the alleviation of inflammation and pain in cats. Six healthy domestic short hair cats were treated orally with various dosage regimes (0.05–0.2 mg/kg/day). Plasma samples were collected at predefined times and quantitatively analysed using liquid/liquid extraction followed by reverse phase HPLC with UV‐detection. Meloxicam plasma concentration data were analysed using the population pharmacokinetic approach (software: NONMEM). The final model was used to simulate different dosage regimes. The plasma concentration–time profiles of meloxicam in cats after oral single and multiple dose administration were best described by an open one‐compartment model with first‐order absorption and first‐order elimination. Pharmacokinetic parameters were estimated to be 0.00656 L/h/kg for the total apparent body clearance (CL/F), 0.245 L/kg for the apparent volume of distribution (V/F), 1.26 1/h for the absorption constant (K_A) and 25.7 h for the mean plasma terminal half‐life. Simulations showed that the median trough steady‐state concentrations of 228 ng/mL were reached after five, one or 6 days following a single initial dose of 0.05, 0.1 and 0.2 mg/kg each followed by 0.05 mg/kg/day.     

High Embryonic Recovery Rates with In vivo and Ex vivo Techniques in the Bitch

The embryonic collection techniques in dogs present a vast methodological variation and low recovery rates. The objectives were to compare and describe two techniques as to the recovery of canine embryos, on the 12th day after the first mating or artificial insemination. Embryos were recovered through uterine horn flushing in vivo, before performing the ovariohysterectomy (OHE) (Group 1; n = 9) or ex vivo, immediately after the OHE (Group 2; n = 9). In total, 43 and 47 embryonic structures were recovered in Groups 1 and 2, respectively. There was no significant difference (p > 0.05) between groups on recovery rates (72.8% and 81.0%, respectively). We inferred that both in vivo and ex vivo techniques allow a high rate of embryonic recovery; in the collection technique prior to the OHE, it is essential to carefully handle the reproductive system during the trans‐surgical period and that the 12th day (D12) after the first mating/artificial insemination is an efficient option for the high recovery rate of morulae and blastocysts.     

The pharmacokinetics, metabolism and urinary detection time of caffeine in camels

The pharmacokinetics of caffeine were determined in 10 camels after an intravenous dose of 2.35 mg kg(-1). The data obtained (median and range) were as follows. The elimination half-life (t(1/2)) was 31.4 (21.2 to 58.9) hours, the steady state volume of distribution (V(SS)) was 0.62 (0.51 to 0.74) litre kg(-1)and the total body clearance (Cl(T)) was 14.7 (8.70 to 19.7) ml kg(-1)per hour. Renal clearance estimated in two camels was 0.62 and 0.34 ml kg(-1)per hour. In vitro plasma protein binding (mean +/-SEM, n = 10) to a concentration of 2 and 8 microg ml(-1)was 36.0 +/- 0.24 and 39.2 +/- 0.36 per cent respectively. Theophylline and theobromine were identified as caffeine metabolites in serum and urine. The terminal elimination half-life of the former, estimated in two camels, was 70. 4 and 124.4 hours. Caffeine could be detected in the urine for 14 days.     

Pathophysiological Responses to Conotoxin Modulation of Voltage-Gated Ion Currents

Voltage-gated ion channels are plasma membrane proteins that generate electrical signals following a change in the membrane voltage. Since they are involved in several physiological processes, their dysfunction may be responsible for a series of diseases and pain states particularly related to neuronal and muscular systems. It is well established for decades that bioactive peptides isolated from venoms of marine mollusks belonging to the Conus genus, collectively known as conotoxins, can target different types and isoforms of these channels exerting therapeutic effects and pain relief. For this reason, conotoxins are widely used for either therapeutic purposes or studies on ion channel mechanisms of action disclosure. In addition their positive property, however, conotoxins may generate pathological states through similar ion channel modulation. In this narrative review, we provide pieces of evidence on the pathophysiological impacts that different members of conotoxin families exert by targeting the three most important voltage-gated channels, such as sodium, calcium, and potassium, involved in cellular processes.