327 research outputs found

    Inter-Allelic Prion Propagation Reveals Conformational Relationships among a Multitude of [PSI] Strains

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    Immense diversity of prion strains is observed, but its underlying mechanism is less clear. Three [PSI] prion strains—named VH, VK, and VL—were previously isolated in the wild-type yeast genetic background. Here we report the generation and characterization of eight new [PSI] isolates, obtained by propagating the wild-type strains with Sup35 proteins containing single amino-acid alterations. The VH strain splits into two distinct strains when propagated in each of the three genetic backgrounds, harboring respectively single mutations of N21L, R28P, and Gi47 (i.e. insertion of a glycine residue at position 47) on the Sup35 N-terminal prion-forming segment. The six new strains exhibit complex inter-conversion patterns, and one of them continuously mutates into another. However, when they are introduced back into the wild-type background, all 6 strains revert to the VH strain. We obtain two more [PSI] isolates by propagating VK and VL with the Gi47 and N21L backgrounds, respectively. The two isolates do not transmit to other mutant backgrounds but revert to their parental strains in the wild-type background. Our data indicate that a large number of [PSI] strains can be built on three basic Sup35 amyloid structures. It is proposed that the three basic structures differ by chain folding topologies, and sub-strains with the same topology differ in distinct ways by local structural adjustments. This “large number of variations on a small number of basic themes” may also be operative in generating strain diversities in other prion elements. It thus suggests a possible general scheme to classify a multitude of prion strains

    Identification of Novel Susceptibility Loci for Kawasaki Disease in a Han Chinese Population by a Genome-Wide Association Study

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    Kawasaki disease (KD) is an acute systemic vasculitis syndrome that primarily affects infants and young children. Its etiology is unknown; however, epidemiological findings suggest that genetic predisposition underlies disease susceptibility. Taiwan has the third-highest incidence of KD in the world, after Japan and Korea. To investigate novel mechanisms that might predispose individuals to KD, we conducted a genome-wide association study (GWAS) in 250 KD patients and 446 controls in a Han Chinese population residing in Taiwan, and further validated our findings in an independent Han Chinese cohort of 208 cases and 366 controls. The most strongly associated single-nucleotide polymorphisms (SNPs) detected in the joint analysis corresponded to three novel loci. Among these KD-associated SNPs three were close to the COPB2 (coatomer protein complex beta-2 subunit) gene: rs1873668 (p = 9.52×10−5), rs4243399 (p = 9.93×10−5), and rs16849083 (p = 9.93×10−5). We also identified a SNP in the intronic region of the ERAP1 (endoplasmic reticulum amino peptidase 1) gene (rs149481, pbest = 4.61×10−5). Six SNPs (rs17113284, rs8005468, rs10129255, rs2007467, rs10150241, and rs12590667) clustered in an area containing immunoglobulin heavy chain variable regions genes, with pbest-values between 2.08×10−5 and 8.93×10−6, were also identified. This is the first KD GWAS performed in a Han Chinese population. The novel KD candidates we identified have been implicated in T cell receptor signaling, regulation of proinflammatory cytokines, as well as antibody-mediated immune responses. These findings may lead to a better understanding of the underlying molecular pathogenesis of KD

    The association between socioeconomic status and traditional chinese medicine use among children in Taiwan

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    <p>Abstract</p> <p>Background</p> <p>Traditional Chinese medicine (TCM) utilization is common in Asian countries. Limited studies are available on the socioeconomic status (SES) associated with TCM use among the pediatric population. We report on the association between SES and TCM use among children and adolescents in Taiwan.</p> <p>Methods</p> <p>A National Health Interview Survey was conducted in Taiwan in 2001 that included 5,971 children and adolescents. We assessed the children's SES using the head of household's education, occupation and income. This information was used to calculate pediatric SES scores, which in turn were divided into quartiles. Children and adolescents who visited TCM in the past month were defined as TCM users.</p> <p>Results</p> <p>Compared to children in the second SES quartile, children in the fourth SES quartile had a higher average number of TCM visits (0.12 vs. 0.06 visits, p = 0.027) and higher TCM use prevalence (5.0% vs. 3.6%, p = 0.024) within the past month. The adjusted odds ratio (OR) for TCM use was higher for children in the fourth SES quartile than for those in the first SES quartile (OR 1.49; 95% confidence interval [CI] 1.02-2.17). The corresponding OR was 2.17 for girls (95% CI 1.24-3.78). The highest-SES girls (aged 10-18 years) were most likely to visit TCM practices (OR 2.47; 95% CI 1.25-4.90).</p> <p>Conclusions</p> <p>Children and adolescents with high SES were more likely to use TCM and especially girls aged 10-18 years. Our findings point to the high use of complementary and alternative medicine among children and adolescents.</p

    Development of a Humanized Antibody with High Therapeutic Potential against Dengue Virus Type 2

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    Dengue virus (DENV) infection remains a serious health threat despite the availability of supportive care in modern medicine. Monoclonal antibodies (mAbs) of DENV would be powerful research tools for antiviral development, diagnosis and pathological investigations. Here we described generation and characterization of seventeen mAbs with high reactivity for E protein of DENV. Four of these mAbs showed high neutralizing activity against DENV-2 infection in mice. The monoclonal antibody mAb DB32-6 showed the strongest neutralizing activity against diverse DENV-2 and protected DENV-2-infected mice against mortality in therapeutic models. We identified neutralizing epitopes of DENV located at residues K310 and E311 of viral envelope protein domain III (E-DIII) through the combination of biological and molecular strategies. Comparing the strong neutralizing activity of mAbs targeting A-strand with mAbs targeting lateral ridge, we found that epitopes located in A-strand induced stronger neutralizing activity than those located on the lateral ridge. DB32-6 humanized version was successfully developed. Humanized DB32-6 variant retained neutralizing activity and prevented DENV infection. Understanding the epitope-based antibody-mediated neutralization is crucial to controlling dengue infection. Additionally, this study also introduces a novel humanized mAb as a candidate for therapy of dengue patients

    Age- and gender-specific population attributable risks of metabolic disorders on all-cause and cardiovascular mortality in Taiwan

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    [[abstract]]ABSTRACT: BACKGROUND: The extent of attributable risks of metabolic syndrome (MetS) and its components on mortality remains unclear, especially with respect to age and gender. We aimed to assess the age- and gender-specific population attributable risks (PARs) for cardiovascular disease (CVD)-related mortality and all-cause mortality for public health planning. METHODS: A total of 2,092 men and 2,197 women 30 years of age and older, who were included in the 2002 Taiwan Survey of Hypertension, Hyperglycemia, and Hyperlipidemia (TwSHHH), were linked to national death certificates acquired through December 31, 2009. Cox proportional hazard models were used to calculate adjusted hazard ratios and PARs for mortality, with a median follow-up of 7.7 years. RESULTS: The respective PAR percentages of MetS for all-cause and CVD-related mortality were 11.6 and 39.2 in men, respectively, and 18.6 and 44.4 in women, respectively. Central obesity had the highest PAR for CVD mortality in women (57.5%), whereas arterial hypertension had the highest PAR in men (57.5%). For all-cause mortality, younger men and post-menopausal women had higher PARs related to Mets and its components; for CVD mortality, post-menopausal women had higher overall PARs than their pre-menopausal counterparts. CONCLUSIONS: MetS has a limited application to the PAR for all-cause mortality, especially in men; its PAR for CVD mortality is more evident. For CVD mortality, MetS components have higher PARs than MetS itself, especially hypertension in men and waist circumference in post-menopausal women. In addition, PARs for diabetes mellitus and low HDL-cholesterol may exceed 20%. We suggest differential control of risk factors in different subpopulation as a strategy to prevent CVD-related mortality

    Augmented TLR2 Expression on Monocytes in both Human Kawasaki Disease and a Mouse Model of Coronary Arteritis

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    BACKGROUND: Kawasaki disease (KD) of unknown immunopathogenesis is an acute febrile systemic vasculitis and the leading cause of acquired heart diseases in childhood. To search for a better strategy for the prevention and treatment of KD, this study compared and validated human KD immunopathogenesis in a mouse model of Lactobacillus casei cell wall extract (LCWE)-induced coronary arteritis. METHODS: Recruited subjects fulfilled the criteria of KD and were admitted for intravenous gamma globulin (IVIG) treatment at the Kaohsiung Chang Gung Memorial Hospital from 2001 to 2009. Blood samples from KD patients were collected before and after IVIG treatment, and cardiovascular abnormalities were examined by transthoracic echocardiography. Wild-type male BALB/c mice (4-week-old) were intraperitoneally injected with LCWE (1 mg/mL) to induce coronary arteritis. The induced immune response in mice was examined on days 1, 3, 7, and 14 post injections, and histopathology studies were performed on days 7 and 14. RESULTS: Both human KD patients and LCWE-treated mice developed coronary arteritis, myocarditis, valvulitis, and pericarditis, as well as elevated plasma levels of interleukin (IL)-2, IL-6, IL-10, monocyte chemoattractant protein (MCP)-1, and tumor necrosis factor (TNF)-α in acute phase. Most of these proinflammatory cytokines declined to normal levels in mice, whereas normal levels were achieved in patients only after IVIG treatment, with a few exceptions. Toll-like receptor (TLR)-2, but not TLR4 surface enhancement on circulating CD14+ monocytes, was augmented in KD patients before IVIG treatment and in LCWE-treated mice, which declined in patients after IVIG treatment. CONCLUSION: This result suggests that that not only TLR2 augmentation on CD14+ monocytes might be an inflammatory marker for both human KD patients and LCWE-induced CAL mouse model but also this model is feasible for studying therapeutic strategies of coronary arteritis in human KD by modulating TLR2-mediated immune activation on CD14+ monocytes
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