Paradoxical risk perception and behaviours related to Avian Flu outbreak and education campaign, Laos

<p>Abstract</p> <p>Background</p> <p>In Laos, small backyard poultry systems predominate (90%). The first lethal human cases of highly pathogenic avian influenza (HPAI) occurred in 2007. Few studies have addressed the impact of outbreaks and education campaigns on a smallholder producer system. We evaluated awareness and behaviours related to educational campaigns and the 2007 HPAI outbreaks.</p> <p>Methods</p> <p>During a national 2-stage cross-sectional randomised survey we interviewed 1098 households using a pre-tested questionnaire in five provinces representative of the Southern to Northern strata of Laos. We used multivariate analysis (Stata, version 8; Stata Corporation, College Station, TX, USA) to analyse factors affecting recollection of HPAI educational messages, awareness of HPAI, and behaviour change.</p> <p>Results</p> <p>Of the 1098 participants, 303 (27.6%) received training on HPAI. The level of awareness was similar to that in 2006. The urban population considered risk to be decreased, yet unsafe behaviours persisted or increased. This contrasted with an increase in awareness and safe behaviour practices in rural areas.</p> <p>Reported behaviour changes in rural areas included higher rates of cessation of poultry consumption and dead poultry burial when compared to 2006. No participants reported poultry deaths to the authorities. Overall, 70% could recall an educational message but the content and accuracy differed widely depending on training exposure. Washing hands and other hygiene advice, messages given during the HPAI educational campaign, were not recalled. Trained persons were able to recall only one message while untrained participants recalled a broader range of messages. Factors associated with an awareness of a threat of AI in Laos were: having received HPAI training, literacy level, access to TV, recent information, living in rural areas.</p> <p>Conclusion</p> <p>We report a paradoxical relationship between unsafe behaviours and risk perception in urban areas, as well as exposure to HPAI training and message misinterpretation. Future educational campaigns need to be tailored to specific target populations and farming styles, for example, small holder farms as compared to commercial farms. Special attention must be given to varying risk perceptions and the risk of misinterpretation of key messages, economic hardship, and real life consequences of reporting.</p

Modulated Instability in Five-Dimensional U(1) Charged AdS Black Hole with R**2-term

We study the effect of R**2 term to the modulated instability in the U(1) charged black hole in five-dimensional Anti-de Sitter space-time. We consider the first-order corrections of R**2 term to the background and the linear order perturbations in the equations of motion. From the analysis, we clarify the effect of R**2 term in the modulated instability, and conclude that fluctuations are stable in the whole bulk in the range of values the coefficient of R**2 term can take.Comment: 19 pages, 1 figures; (v4) Published version in JHE

Agent based modelling helps in understanding the rules by which fibroblasts support keratinocyte colony formation

Background: Autologous keratincoytes are routinely expanded using irradiated mouse fibroblasts and bovine serum for clinical use. With growing concerns about the safety of these xenobiotic materials, it is desirable to culture keratinocytes in media without animal derived products. An improved understanding of epithelial/mesenchymal interactions could assist in this. Methodology/Principal Findings: A keratincyte/fibroblast o-culture model was developed by extending an agent-based keratinocyte colony formation model to include the response of keratinocytes to both fibroblasts and serum. The model was validated by comparison of the in virtuo and in vitro multicellular behaviour of keratinocytes and fibroblasts in single and co-culture in Greens medium. To test the robustness of the model, several properties of the fibroblasts were changed to investigate their influence on the multicellular morphogenesis of keratinocyes and fibroblasts. The model was then used to generate hypotheses to explore the interactions of both proliferative and growth arrested fibroblasts with keratinocytes. The key predictions arising from the model which were confirmed by in vitro experiments were that 1) the ratio of fibroblasts to keratinocytes would critically influence keratinocyte colony expansion, 2) this ratio needed to be optimum at the beginning of the co-culture, 3) proliferative fibroblasts would be more effective than irradiated cells in expanding keratinocytes and 4) in the presence of an adequate number of fibroblasts, keratinocyte expansion would be independent of serum. Conclusions: A closely associated computational and biological approach is a powerful tool for understanding complex biological systems such as the interactions between keratinocytes and fibroblasts. The key outcome of this study is the finding that the early addition of a critical ratio of proliferative fibroblasts can give rapid keratinocyte expansion without the use of irradiated mouse fibroblasts and bovine serum

Differential effects of cytokines and corticosteroids on Toll-like receptor 2 expression and activity in human airway epithelia

<p>Abstract</p> <p>Background</p> <p>The recognition of microbial molecular patterns via Toll-like receptors (TLRs) is critical for mucosal defenses.</p> <p>Methods</p> <p>Using well-differentiated primary cultures of human airway epithelia, we investigated the effects of exposure of the cells to cytokines (TNF-α and IFN-γ) and dexamethasone (dex) on responsiveness to the TLR2/TLR1 ligand Pam3CSK4. Production of IL-8, CCL20, and airway surface liquid antimicrobial activity were used as endpoints.</p> <p>Results</p> <p>Microarray expression profiling in human airway epithelia revealed that first response cytokines markedly induced TLR2 expression. Real-time PCR confirmed that cytokines (TNF-α and IFN-γ), dexamethasone (dex), or cytokines + dex increased TLR2 mRNA abundance. A synergistic increase was seen with cytokines + dex. To assess TLR2 function, epithelia pre-treated with cytokines ± dex were exposed to the TLR2/TLR1 ligand Pam3CSK4 for 24 hours. While cells pre-treated with cytokines alone exhibited significantly enhanced IL-8 and CCL20 secretion following Pam3CSK4, mean IL-8 and CCL20 release decreased in Pam3CSK4 stimulated cells following cytokines + dex pre-treatment. This marked increase in inflammatory gene expression seen after treatment with cytokines followed by the TLR2 ligand did not correlate well with NF-κB, Stat1, or p38 MAP kinase pathway activation. Cytokines also enhanced TLR2 agonist-induced beta-defensin 2 mRNA expression and increased the antimicrobial activity of airway surface liquid. Dex blocked these effects.</p> <p>Conclusion</p> <p>While dex treatment enhanced TLR2 expression, co-administration of dex with cytokines inhibited airway epithelial cell responsiveness to TLR2/TLR1 ligand over cytokines alone. Enhanced functional TLR2 expression following exposure to TNF-α and IFN-γ may serve as a dynamic means to amplify epithelial innate immune responses during infectious or inflammatory pulmonary diseases.</p

The Tyrosine Kinase Csk Dimerizes through Its SH3 Domain

The Src family kinases possess two sites of tyrosine phosphorylation that are critical to the regulation of kinase activity. Autophosphorylation on an activation loop tyrosine residue (Tyr 416 in commonly used chicken c-Src numbering) increases catalytic activity, while phosphorylation of a C-terminal tyrosine (Tyr 527 in c-Src) inhibits activity. The latter modification is achieved by the tyrosine kinase Csk (C-terminal Src Kinase), but the complete inactivation of the Src family kinases also requires the dephosphorylation of the activation loop tyrosine. The SH3 domain of Csk recruits the tyrosine phosphatase PEP, allowing for the coordinated inhibition of Src family kinase activity. We have discovered that Csk forms homodimers through interactions mediated by the SH3 domain in a manner that buries the recognition surface for SH3 ligands. The formation of this dimer would therefore block the recruitment of tyrosine phosphatases and may have important implications for the regulation of Src kinase activity

Cloning, tissue and ontogenetic expression of the taurine transporter in the flatfish Senegalese sole (Solea senegalensis)

Flatfish species seem to require dietary taurine for normal growth and development. Although dietary taurine supplementation has been recommended for flatfish, little is known about the mechanisms of taurine absorption in the digestive tract of flatfish throughout ontogeny. This study described the cloning and ontogenetic expression of the taurine transporter (TauT) in the flatfish Senegalese sole (Solea senegalensis). Results showed a high similarity between TauT in Senegalese sole and other vertebrates, but a change in TauT amino acid sequences indicates that taurine transport may differ between mammals and fish, reptiles or birds. Moreover, results showed that Senegalese sole metamorphosis is an important developmental trigger to promote taurine transport in larvae, especially in muscle tissues, which may be important for larval growth. Results also indicated that the capacity to uptake dietary taurine in the digestive tract is already established in larvae at the onset of metamorphosis. In Senegalese sole juveniles, TauT expression was highest in brain, heart and eye. These are organs where taurine is usually found in high concentrations and is believed to play important biological roles. In the digestive tract of juveniles, TauT was more expressed in stomach and hindgut, indicating that dietary taurine is quickly absorbed when digestion begins and taurine endogenously used for bile salt conjugation may be recycled at the posterior end of the digestive tract. Therefore, these results suggest an enterohepatic recycling pathway for taurine in Senegalese sole, a process that may be important for maintenance of the taurine body levels in flatfish species

Cyp26b1 Regulates Retinoic Acid-Dependent Signals in T Cells and Its Expression Is Inhibited by Transforming Growth Factor-β

The vitamin A metabolite, retinoic acid (RA), plays important roles in the regulation of lymphocyte properties. Dendritic cells in gut-related lymphoid organs can produce RA, thereby imprinting gut-homing specificity on T cells and enhancing transforming growth factor (TGF)-β-dependent induction of Foxp3+ regulatory T cells upon antigen presentation. In general, RA concentrations in cells and tissues are regulated by its degradation as well. However, it remained unclear if T cells could actively catabolize RA.We assessed the expression of known RA-catabolizing enzymes in T cells from mouse lymphoid tissues. Antigen-experienced CD44+ T cells in gut-related lymphoid organs selectively expressed Cyp26b1, a member of the cytochrome P450 family 26. However, T cells in the spleen or skin-draining lymph nodes did not significantly express Cyp26b1. Accordingly, physiological levels of RA (1-10 nM) could induce Cyp26b1 expression in naïve T cells upon activation in vitro, but could not do so in the presence of TGF-β. Overexpression of Cyp26b1 significantly suppressed the RA effect to induce expression of the gut-homing receptor CCR9 on T cells. On the other hand, knocking down Cyp26b1 gene expression with small interfering RNA or inhibiting CYP26 enzymatic activity led to enhancement of the RA-induced CCR9 expression.Our data demonstrate a role for CYP26B1 in regulating RA-dependent signals in activated T cells but not during TGF-β-dependent differentiation to Foxp3+ regulatory T cells. Aberrant expression of CYP26B1 may disturb T cell trafficking and differentiation in the gut and its related lymphoid organs

Combined effect of regulatory polymorphisms on transcription of UGT1A1 as a cause of Gilbert syndrome

<p>Abstract</p> <p>Background</p> <p>Gilbert syndrome is caused by defects in bilirubin UDP-glucuronosyltransferase (UGT1A1). The most common variation believed to be involved is A(TA)7TAA. Although several polymorphisms have been found to link with A(TA)7TAA, the combined effect of regulatory polymorphisms in the development of Gilbert syndrome remains unclear.</p> <p>Methods</p> <p>In an analysis of 15 patients and 60 normal subjects, we detected 14 polymorphisms and nine haplotypes in the regulatory region. We classified the 4-kbp regulatory region of the patients into: the TATA box including A(TA)7TAA; a phenobarbital responsive enhancer module including c.-3275T>G; and a region including other ten linked polymorphisms. The effect on transcription of these polymorphisms was studied.</p> <p>Results</p> <p>All haplotypes with A(TA)7TAA had c.-3275T>G and additional polymorphisms. In an <it>in-vitro </it>expression study of the 4-kbp regulatory region, A(TA)7TAA alone did not significantly reduce transcription. In contrast, c.-3275T>G reduced transcription to 69% of that of wild type, and the linked polymorphisms reduced transcription to 88% of wild type. Transcription of the typical regulatory region of the patients was 56% of wild type. Co-expression of constitutive androstane receptor (CAR) increased the transcription of wild type by a factor of 4.3. Each polymorphism by itself did not reduce transcription to the level of the patients, however, even in the presence of CAR.</p> <p>Conclusions</p> <p>These results imply that co-operation of A(TA)7TAA, c.-3275T>G and the linked polymorphisms is necessary in causing Gilbert syndrome.</p

A Novel Dimeric Inhibitor Targeting Beta2GPI in Beta2GPI/Antibody Complexes Implicated in Antiphospholipid Syndrome

Background: b2GPI is a major antigen for autoantibodies associated with antiphospholipid syndrome (APS), an autoimmune disease characterized by thrombosis and recurrent pregnancy loss. Only the dimeric form of b2GPI generated by anti-b2GPI antibodies is pathologically important, in contrast to monomeric b2GPI which is abundant in plasma. Principal Findings: We created a dimeric inhibitor, A1-A1, to selectively target b2GPI in b2GPI/antibody complexes. To make this inhibitor, we isolated the first ligand-binding module from ApoER2 (A1) and connected two A1 modules with a flexible linker. A1-A1 interferes with two pathologically important interactions in APS, the binding of b2GPI/antibody complexes with anionic phospholipids and ApoER2. We compared the efficiency of A1-A1 to monomeric A1 for inhibition of the binding of b2GPI/antibody complexes to anionic phospholipids. We tested the inhibition of b2GPI present in human serum, b2GPI purified from human plasma and the individual domain V of b2GPI. We demonstrated that when b2GPI/antibody complexes are formed, A1-A1 is much more effective than A1 in inhibition of the binding of b2GPI to cardiolipin, regardless of the source of b2GPI. Similarly, A1-A1 strongly inhibits the binding of dimerized domain V of b2GPI to cardiolipin compared to the monomeric A1 inhibitor. In the absence of anti-b2GPI antibodies, both A1-A1 and A1 only weakly inhibit the binding of pathologically inactive monomeric b2GPI to cardiolipin. Conclusions: Our results suggest that the approach of using a dimeric inhibitor to block b2GPI in the pathologica

Enhanced peripheral toll-like receptor responses in psychosis: further evidence of a pro-inflammatory phenotype

Low-grade peripheral inflammation is often present in psychotic patients. Toll-like receptors (TLRs) are pattern-recognition molecules that initiate inflammation. Our objective was to investigate the peripheral TLR activity in psychosis. Forty schizophrenia patients, twenty bipolar patients and forty healthy controls (HC) were recruited. Donated whole blood was cultured with TLR agonists for 24 h. Cell supernatants were analysed using a multiplex enzyme-linked immunosorbent assay approach to measure IL-1β, IL-6, IL-8 and tumour necrosis factor-α (TNFα). Plasma was analysed for cytokines, cortisol and acute phase proteins. Here, we show that selective TLR agonist-induced cytokine (IL-1β, IL-6, IL-8 and TNFα) release is enhanced in stimulated whole blood from schizophrenia and bipolar patients compared with HC. An exaggerated release of IL-1β, IL-6 and TNFα following treatment with the TLR2 agonist HKLM was detected in both disorders compared with controls. Enhanced TLR4-induced increases in IL-1β for both disorders coupled with TNFα increases for bipolar patients were observed. TLR8-induced increases in IL-1β for both disorders as well as IL-6 and TNFα increases for bipolar patients were detected. TLR9-induced increases in IL-8 for schizophrenia patients were also observed. No differences in TLR1, TLR3, TLR5, TLR6 or TLR7 activity were detected. Plasma levels of IL-6 were significantly elevated in bipolar patients while TNFα levels were significantly elevated in schizophrenia patients compared with controls. Plasma acute phase proteins were significantly elevated in bipolar patients. These data demonstrate that specific alterations in TLR agonist-mediated cytokine release contribute to the evidence of immune dysfunction in psychotic disorders