Reproductive performance in sows in relation to Japanese Encephalitis Virus seropositivity in an endemic area

Japanese Encephalitis Virus (JEV) is considered an important reproductive pathogen in pigs. Most studies of the reproductive impact of JEV have been conducted in areas where the disease occurs in seasonal epidemics. In this study, the associations between seropositivity for JEV, measured with an IgG ELISA, and the number of piglets born alive and stillborn were investigated in a tropical area endemic for JEV in Vietnam. Sixty percent of sows from four farms in the Mekong delta of Vietnam were seropositive to JEV and the Odds Ratio for a sow being infected was highest (6.4) in sows above 3.5 years (95% confidence interval 2.2–18.3). There was an association between increasing Optical Density (OD) values from the ELISA and the number of stillborn piglets in sows less than 1.5 years, but no effect of seropositivity could be shown when all sows were studied. OD values had an effect (p = 0.04) on the number of piglets born alive in the statistical analysis only when interacting with the effect of the breeds. An increase in mean OD value of the herd was correlated (p < 0.0001) with an increase in the number of piglets born alive. In this study, there was evidence of a negative association between seropositivity for JEV and the reproductive performance only in sows less than 1.5 years in endemic areas. This could be explained by a year-round infection with the virus, which would lead to immunity in many gilts before their first pregnancy. This, in turn, may imply that JEV infection in pigs is of minor importance for the reproductive performance in endemic areas

Differential spatial modulation for high-rate transmission systems

This paper introduces a new differential spatial modulation (DSM) scheme which subsumes both the previously introduced DSM and high-rate spatial modulation (HR-SM) for wireless multiple input multiple output (MIMO) transmission. By combining the codeword design method of the HR-SM scheme with the encoding method of the DSM scheme, we develop a high-rate differential spatial modulation (HR-DSM) scheme equipped with an arbitrary number of transmit antennas that requires channel state information (CSI) neither at the transmitter nor at the receiver. The proposed approach can be applied to any equal energy signal constellations. The bit error rate (BER) performance of the proposed HR-DSM schemes is evaluated by using both theoretical upper bound and computer simulations. It is shown that for the same spectral efficiency and antenna configuration, the proposed HR-DSM outperforms the DSM in terms of bit error rate (BER) performance

Farm-Level Risk Factors for Fish-Borne Zoonotic Trematode Infection in Integrated Small-Scale Fish Farms in Northern Vietnam

BACKGROUND: Northern Vietnam is an endemic region for fish-borne zoonotic trematodes (FZT), including liver and intestinal flukes. Humans acquire the FZT infection by eating raw or inadequately cooked fish. The production of FZT-free fish in aquaculture is a key component in establishing a sustainable program to prevent and control the FZT transmission to humans. Interventions in aquaculture should be based on knowledge of the main risk factors associated with FZT transmission. METHODOLOGY/PRINCIPAL FINDINGS: A longitudinal study was carried out from June 2006 to May 2007 in Nam Dinh province, Red River Delta to investigate the development and risk factors of FZT infections in freshwater cultured fish. A total of 3820 fish were sampled six times at two-month intervals from 96 fish farms. Logistic analysis with repeated measurements was used to evaluate potential risk factors based on information collected through questionnaire interviews with 61 fish farm owners. The results showed that the FZT infections significantly increased from first sampling in June to July 2006 (65%) to sixth sampling in April to May, 2007 (76%). The liver fluke, Clonorchis sinensis and different zoonotic intestinal flukes including Haplochis pumilio, H. taichui, H. yokogawai, Centrocestus formosanus and Procerovum varium were found in sampled fish. Duration of fish cultured (sampling times), mebendazole drug self-medication of household members, presence of snails in the pond, and feeding fish with green vegetation collected outside fish farms all had a significant effect on the development of FZT prevalence in the fish. CONCLUSIONS/SIGNIFICANCE: The FZT prevalence in fish increased by 11 percentage points during a one-year culture period and the risk factors for the development of infection were identified. Results also highlight that the young fish are already highly infected when stocked into the grow-out systems. This knowledge should be incorporated into control programs of FZT transmission in integrated small-scale aquaculture nursery and grow-out systems in Vietnam

Physiological Induction of Regulatory Qa-1-Restricted CD8+ T Cells Triggered by Endogenous CD4+ T Cell Responses

T cell-dependent autoimmune diseases are characterized by the expansion of T cell clones that recognize immunodominant epitopes on the target antigen. As a consequence, for a given autoimmune disorder, pathogenic T cell clones express T cell receptors with a limited number of variable regions that define antigenic specificity. Qa-1, a MHC class I-like molecule, presents peptides from the variable region of TCRs to Qa-1-restricted CD8+ T cells. The induction of Vß-specific CD8+ T cells has been harnessed in an immunotherapeutic strategy known as the “T cell vaccination” (TCV) that comprises the injection of activated and attenuated CD4+ T cell clones so as to induce protective CD8+ T cells. We hypothesized that Qa-1-restricted CD8+ regulatory T cells could also constitute a physiologic regulatory arm of lymphocyte responses upon expansion of endogenous CD4+ T cells, in the absence of deliberate exogenous T cell vaccination. We immunized mice with two types of antigenic challenges in order to sequentially expand antigen-specific endogenous CD4+ T cells with distinct antigenic specificities but characterized by a common Vß chain in their TCR. The first immunization was performed with a non-self antigen while the second challenge was performed with a myelin-derived peptide known to drive experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. We show that regulatory Vß-specific Qa-1-restricted CD8+ T cells induced during the first endogenous CD4+ T cell responses are able to control the expansion of subsequently mobilized pathogenic autoreactive CD4+ T cells. In conclusion, apart from the immunotherapeutic TCV, Qa-1-restricted specialized CD8+ regulatory T cells can also be induced during endogenous CD4+ T cell responses. At variance with other regulatory T cell subsets, the action of these Qa-1-restricted T cells seems to be restricted to the immediate re-activation of CD4+ T cells

Copper-Mediated Amidation of Heterocyclic and Aromatic C−H Bonds

A copper-mediated aerobic coupling reaction enables direct amidation of heterocycles or aromatics having weakly acidic C−H bonds with a variety of nitrogen nucleophiles. These reactions provide efficient access to many biologically important skeletons, including ones with the potential to serve as inhibitors of HMTs.Chemistry and Chemical Biolog

Genome-wide sequencing of longan (Dimocarpus longan Lour.) provides insights into molecular basis of its polyphenol-rich characteristics

Longan (Dimocarpus longan Lour.), an important subtropical fruit in the family Sapindaceae, is grown in more than 10 countries. Longan is an edible drupe fruit and a source of traditional medicine with polyphenol-rich traits. Tree size, alternate bearing, and witches' broom disease still pose serious problems. To gain insights into the genomic basis of longan traits, a draft genome sequence was assembled. The draft genome (about 471.88 Mb) of a Chinese longan cultivar, “Honghezi,” was estimated to contain 31 007 genes and 261.88 Mb of repetitive sequences. No recent whole-genome-wide duplication event was detected in the genome. Whole-genome resequencing and analysis of 13 cultivated D. longan accessions revealed the extent of genetic diversity. Comparative transcriptome studies combined with genome-wide analysis revealed polyphenol-rich and pathogen resistance characteristics. Genes involved in secondary metabolism, especially those from significantly expanded (DHS, SDH, F3΄H, ANR, and UFGT) and contracted (PAL, CHS, and F3΄5΄H) gene families with tissue-specific expression, may be important contributors to the high accumulation levels of polyphenolic compounds observed in longan fruit. The high number of genes encoding nucleotide-binding site leucine-rich repeat (NBS-LRR) and leucine-rich repeat receptor-like kinase proteins, as well as the recent expansion and contraction of the NBS-LRR family, suggested a genomic basis for resistance to insects, fungus, and bacteria in this fruit tree. These data provide insights into the evolution and diversity of the longan genome. The comparative genomic and transcriptome analyses provided information about longan-specific traits, particularly genes involved in its polyphenol-rich and pathogen resistance characteristics

Crosstalk between Mitochondrial and Sarcoplasmic Reticulum Ca2+ Cycling Modulates Cardiac Pacemaker Cell Automaticity

Mitochondria dynamically buffer cytosolic Ca(2+) in cardiac ventricular cells and this affects the Ca(2+) load of the sarcoplasmic reticulum (SR). In sinoatrial-node cells (SANC) the SR generates periodic local, subsarcolemmal Ca(2+) releases (LCRs) that depend upon the SR load and are involved in SANC automaticity: LCRs activate an inward Na(+)-Ca(2+) exchange current to accelerate the diastolic depolarization, prompting the ensemble of surface membrane ion channels to generate the next action potential (AP).To determine if mitochondrial Ca(2+) (Ca(2+) (m)), cytosolic Ca(2+) (Ca(2+) (c))-SR-Ca(2+) crosstalk occurs in single rabbit SANC, and how this may relate to SANC normal automaticity.Inhibition of mitochondrial Ca(2+) influx into (Ru360) or Ca(2+) efflux from (CGP-37157) decreased [Ca(2+)](m) to 80 ± 8% control or increased [Ca(2+)](m) to 119 ± 7% control, respectively. Concurrent with inhibition of mitochondrial Ca(2+) influx or efflux, the SR Ca(2+) load, and LCR size, duration, amplitude and period (imaged via confocal linescan) significantly increased or decreased, respectively. Changes in total ensemble LCR Ca(2+) signal were highly correlated with the change in the SR Ca(2+) load (r(2) = 0.97). Changes in the spontaneous AP cycle length (Ru360, 111 ± 1% control; CGP-37157, 89 ± 2% control) in response to changes in [Ca(2+)](m) were predicted by concurrent changes in LCR period (r(2) = 0.84).A change in SANC Ca(2+) (m) flux translates into a change in the AP firing rate by effecting changes in Ca(2+) (c) and SR Ca(2+) loading, which affects the characteristics of spontaneous SR Ca(2+) release

The Sudden Dominance of blaCTX–M Harbouring Plasmids in Shigella spp. Circulating in Southern Vietnam

Shigellosis is a disease caused by bacteria belonging to Shigella spp. and is a leading cause of bacterial gastrointestinal infections in infants in unindustrialized countries. The Shigellae are dynamic and capable of rapid change when placed under selective pressure in a human population. Extended spectrum beta lactamases (ESBLs) are enzymes capable of degrading cephalosporins (a group of antimicrobial agents) and the genes that encode them are common in pathogenic E. coli and other related organisms in industrialized countries. In southern Vietnam, we have isolated multiple cephalosporin-resistant Shigella that express ESBLs. Furthermore, over two years these strains have replaced strains isolated from patients with shigellosis that cannot express ESBLs. Our work describes the genes responsible for this characteristic and we investigate one of the elements carrying one of these genes. These finding have implications for treatment of shigellosis and support the growing necessity for vaccine development. Our findings also may be pertinent for other countries undergoing a similar economic transition to Vietnam's and the corresponding effect on bacterial populations