1,778 research outputs found
Seroprevalence of Hepatitis E virus (HEV) in domestic non-commercial pigs reared in small-scale farms and wild boar in South of Brazil
Hepatitis E is a zoonotic emerging disease distributed worldwide. The domestic swine and wild boars (Sus scrofa) are known as important reservoirs of HEV although HEV infections have been detected in other animal species. The southern region of Brazil has the largest swine productions in the country, ranging from highly-specialized commercial swine productions to small-scale non-commercial pig farms. The small-scale farms allow interactions between wild boars and domestic pigs, when occasionally pathogens transmission can occur between these populations. The aim of this study was to determine HEV seroprevalence in non-commercial domestic pigs and wild boars from two southern Brazilian states (RS: Rio Grande do Sul; SC: Santa Catarina), and discuss if the consumption of raw or undercooked meat from these animals is a potential risk to public health. Animals from RS and SC States were sampled. Serum was harvested from wild boar hunted between 2012 and 2016, and from non-commercial small-scale pig farms in 2014. Overall 249 wild boars (56 from RS and 193 from SC) and 382 pigs (261 from RS and 121 from SC) were tested to detect anti-HEV IgG antibodies using a commercial HEV antibody ELISA kit (Thermo fisher), specific for swine. Overall difference was observed (P\u3c0.0001) regarding HEV seroprevalence between wild boar 4.42% (n=249) and non-commercial domestic pigs 46.60% (n=382). In relation to wild boars samples, higher seroprevalence for Hepatitis E was observed in RS (14.29%; n=56) and lower in SC (1.55%; n=193; P\u3c0.0004). In relation to pigs, RS had also higher seroprevalence (53.26%; n=261) than SC (32.23%; n=121; P\u3c0.0002). Although interactions between wild boar and non-commercial domestic pigs are known to occur, the lowest antibody detection in wild boar suggest that these contact may not be sufficient to explain seroprevalence in studied populations. Our results indicate that non-commercial pigs are a more likely source of infection for the human population than wild boar
What Can WMAP Tell Us About The Very Early Universe? New Physics as an Explanation of Suppressed Large Scale Power and Running Spectral Index
The Wilkinson Microwave Anisotropy Probe microwave background data may be
giving us clues about new physics at the transition from a ``stringy'' epoch of
the universe to the standard Friedmann Robertson Walker description. Deviations
on large angular scales of the data, as compared to theoretical expectations,
as well as running of the spectral index of density perturbations, can be
explained by new physics whose scale is set by the height of an inflationary
potential. As examples of possible signatures for this new physics, we study
the cosmic microwave background spectrum for two string inspired models: 1)
modifications to the Friedmann equations and 2) velocity dependent potentials.
The suppression of low ``l'' modes in the microwave background data arises due
to the new physics. In addition, the spectral index is red (n<1) on small
scales and blue (n>1) on large scales, in agreement with data.Comment: 18 pages, 2 figures, submitted for publication in Physical Review D,
references added in this versio
SN1A data and the CMB of Modified Curvature at short and long distances
The SN1a data, although inconclusive, when combined with other observations
makes a strong case that our universe is presently dominated by dark energy. We
investigate the possibility that large distance modifications of the curvature
of the universe would perhaps offer an alternative explanation of the
observation. Our calculations indicate that a universe made up of no dark
energy but instead, with a modified curvature at large scales, is not
scale-invariant, therefore quite likely it is ruled out by the CMB
observations. The sensitivity of the CMB spectrum is checked for the whole
range of mode modifications of large or short distance physics. The spectrum is
robust against modifications of short-distance physics and the UV cutoff when:
the initial state is the adiabatic vacuum, and the inflationary background
space is de Sitter.Comment: 13 pages, 2 eps figures, typos corrected, references added; to appear
in Phys. Rev.
Classification of Dengue Fever Patients Based on Gene Expression Data Using Support Vector Machines
Background: Symptomatic infection by dengue virus (DENV) can range from dengue fever (DF) to dengue haemorrhagic fever (DHF), however, the determinants of DF or DHF progression are not completely understood. It is hypothesised that host innate immune response factors are involved in modulating the disease outcome and the expression levels of genes involved in this response could be used as early prognostic markers for disease severity.
Methodology/Principal Findings: mRNA expression levels of genes involved in DENV innate immune responses were measured using quantitative real time PCR (qPCR). Here, we present a novel application of the support vector machines (SVM) algorithm to analyze the expression pattern of 12 genes in peripheral blood mononuclear cells (PBMCs) of 28 dengue patients (13 DHF and 15 DF) during acute viral infection. The SVM model was trained using gene expression data of these genes and achieved the highest accuracy of ,85% with leave-one-out cross-validation. Through selective removal of gene expression data from the SVM model, we have identified seven genes (MYD88, TLR7, TLR3, MDA5, IRF3, IFN-a and CLEC5A) that may be central in differentiating DF patients from DHF, with MYD88 and TLR7 observed to be the most important. Though the individual removal of expression data of five other genes had no impact on the overall accuracy, a significant combined role was observed when the SVM model of the two main genes (MYD88 and TLR7) was re-trained to include the five genes, increasing the overall accuracy to ,96%.
Conclusions/Significance: Here, we present a novel use of the SVM algorithm to classify DF and DHF patients, as well as to elucidate the significance of the various genes involved. It was observed that seven genes are critical in classifying DF and DHF patients: TLR3, MDA5, IRF3, IFN-a, CLEC5A, and the two most important MYD88 and TLR7. While these preliminary results are promising, further experimental investigation is necessary to validate their specific roles in dengue disease
Identification of Continuous Human B-Cell Epitopes in the Envelope Glycoprotein of Dengue Virus Type 3 (DENV-3)
BACKGROUND:Dengue virus infection is a growing global public health concern in tropical and subtropical regions of the world. Dengue vaccine development has been hampered by concerns that cross-reactive immunological memory elicited by a candidate vaccine could increase the risk of development of more severe clinical forms. One possible strategy to reduce risks associated with a dengue vaccine is the development of a vaccine composed of selected critical epitopes of each of the serotypes. METHODOLOGY/PRINCIPAL FINDINGS:Synthetic peptides were used to identify B-cell epitopes in the envelope (E) glycoprotein of dengue virus type 3 (DENV-3). Eleven linear, immunodominant epitopes distributed in five regions at amino acid (aa) positions: 51-65, 71-90, 131-170, 196-210 and 246-260 were identified by employing an enzyme- linked immunosorbent assay (ELISA), using a pool of human sera from dengue type 3 infected individuals. Peptides 11 (aa51-65), 27 and 28 (aa131-150) also reacted with dengue 1 (DENV-1) and dengue 2 (DENV-2) patient sera as analyzed through the ROC curves generated for each peptide by ELISA and might have serotype specific diagnostic potential. Mice immunized against each one of the five immunogenic regions showed epitopes 51-65, 131-170, 196-210 and 246-260 elicited the highest antibody response and epitopes131-170, 196-210 and 246-260, elicited IFN-gamma production and T CD4+ cell response, as evaluated by ELISA and ELISPOT assays respectively. CONCLUSIONS/SIGNIFICANCE:Our study identified several useful immunodominant IgG-specific epitopes on the envelope of DENV-3. They are important tools for understanding the mechanisms involved in antibody dependent enhancement and immunity. If proven protective and safe, in conjunction with others well-documented epitopes, they might be included into a candidate epitope-based vaccine
Gene Expression Profiling during Early Acute Febrile Stage of Dengue Infection Can Predict the Disease Outcome
Background: We report the detailed development of biomarkers to predict the clinical outcome under dengue infection. Transcriptional signatures from purified peripheral blood mononuclear cells were derived from whole-genome gene-expression microarray data, validated by quantitative PCR and tested in independent samples. Methodology/Principal Findings: The study was performed on patients of a well-characterized dengue cohort from Recife, Brazil. The samples analyzed were collected prospectively from acute febrile dengue patients who evolved with different degrees of disease severity: classic dengue fever or dengue hemorrhagic fever (DHF) samples were compared with similar samples from other non-dengue febrile illnesses. The DHF samples were collected 2-3 days before the presentation of the plasma leakage symptoms. Differentially-expressed genes were selected by univariate statistical tests as well as multivariate classification techniques. The results showed that at early stages of dengue infection, the genes involved in effector mechanisms of innate immune response presented a weaker activation on patients who later developed hemorrhagic fever, whereas the genes involved in apoptosis were expressed in higher levels. Conclusions/Significance: Some of the gene expression signatures displayed estimated accuracy rates of more than 95%, indicating that expression profiling with these signatures may provide a useful means of DHF prognosis at early stages of infection. © 2009 Nascimento et al
Prevalência de violência física relatada contra crianças em uma população de ambulatório pediátrico
Analysis of the Ush2a Gene in Medaka Fish (Oryzias latipes)
Patients suffering from Usher syndrome (USH) exhibit sensorineural hearing loss, retinitis pigmentosa (RP) and, in some cases, vestibular dysfunction. USH is the most common genetic disorder affecting hearing and vision and is included in a group of hereditary pathologies associated with defects in ciliary function known as ciliopathies. This syndrome is clinically classified into three types: USH1, USH2 and USH3. USH2 accounts for well over one-half of all Usher cases and mutations in the USH2A gene are responsible for the majority of USH2 cases, but also for atypical Usher syndrome and recessive non-syndromic RP. Because medaka fish (Oryzias latypes) is an attractive model organism for genetic-based studies in biomedical research, we investigated the expression and function of the USH2A ortholog in this teleost species. Ol-Ush2a encodes a protein of 5.445 aa codons, containing the same motif arrangement as the human USH2A. Ol-Ush2a is expressed during early stages of medaka fish development and persists into adulthood. Temporal Ol-Ush2a expression analysis using whole mount in situ hybridization (WMISH) on embryos at different embryonic stages showed restricted expression to otoliths and retina, suggesting that Ol-Ush2a might play a conserved role in the development and/or maintenance of retinal photoreceptors and cochlear hair cells. Knockdown of Ol-Ush2a in medaka fish caused embryonic developmental defects (small eyes and heads, otolith malformations and shortened bodies with curved tails) resulting in late embryo lethality. These embryonic defects, observed in our study and in other ciliary disorders, are associated with defective cell movement specifically implicated in left-right (LR) axis determination and planar cell polarity (PCP)
Alternative Complement Pathway Deregulation Is Correlated with Dengue Severity
BACKGROUND:The complement system, a key component that links the innate and adaptive immune responses, has three pathways: the classical, lectin, and alternative pathways. In the present study, we have analyzed the levels of various complement components in blood samples from dengue fever (DF) and dengue hemorrhagic fever (DHF) patients and found that the level of complement activation is associated with disease severity. METHODS AND RESULTS:Patients with DHF had lower levels of complement factor 3 (C3; p = 0.002) and increased levels of C3a, C4a and C5a (p<0.0001) when compared to those with the less severe form, DF. There were no significant differences between DF and DHF patients in the levels of C1q, immunocomplexes (CIC-CIq) and CRP. However, small but statistically significant differences were detected in the levels of MBL. In contrast, the levels of two regulatory proteins of the alternative pathway varied widely between DF and DHF patients: DHF patients had higher levels of factor D (p = 0.01), which cleaves factor B to yield the active (C3bBb) C3 convertase, and lower levels of factor H (p = 0.03), which inactivates the (C3bBb) C3 convertase, than did DF patients. When we considered the levels of factors D and H together as an indicator of (C3bBb) C3 convertase regulation, we found that the plasma levels of these regulatory proteins in DHF patients favored the formation of the (C3bBb) C3 convertase, whereas its formation was inhibited in DF patients (p<0.0001). CONCLUSION:The data suggest that an imbalance in the levels of regulatory factors D and H is associated with an abnormal regulation of complement activity in DHF patients
Cross-ancestry GWAS meta-analysis identifies six breast cancer loci in African and European ancestry women.
Our study describes breast cancer risk loci using a cross-ancestry GWAS approach. We first identify variants that are associated with breast cancer at P < 0.05 from African ancestry GWAS meta-analysis (9241 cases and 10193 controls), then meta-analyze with European ancestry GWAS data (122977 cases and 105974 controls) from the Breast Cancer Association Consortium. The approach identifies four loci for overall breast cancer risk [1p13.3, 5q31.1, 15q24 (two independent signals), and 15q26.3] and two loci for estrogen receptor-negative disease (1q41 and 7q11.23) at genome-wide significance. Four of the index single nucleotide polymorphisms (SNPs) lie within introns of genes (KCNK2, C5orf56, SCAMP2, and SIN3A) and the other index SNPs are located close to GSTM4, AMPD2, CASTOR2, and RP11-168G16.2. Here we present risk loci with consistent direction of associations in African and European descendants. The study suggests that replication across multiple ancestry populations can help improve the understanding of breast cancer genetics and identify causal variants
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