152 research outputs found

    A geometric network model of intrinsic grey-matter connectivity of the human brain

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    Network science provides a general framework for analysing the large-scale brain networks that naturally arise from modern neuroimaging studies, and a key goal in theoretical neuro- science is to understand the extent to which these neural architectures influence the dynamical processes they sustain. To date, brain network modelling has largely been conducted at the macroscale level (i.e. white-matter tracts), despite growing evidence of the role that local grey matter architecture plays in a variety of brain disorders. Here, we present a new model of intrinsic grey matter connectivity of the human connectome. Importantly, the new model incorporates detailed information on cortical geometry to construct ‘shortcuts’ through the thickness of the cortex, thus enabling spatially distant brain regions, as measured along the cortical surface, to communicate. Our study indicates that structures based on human brain surface information differ significantly, both in terms of their topological network characteristics and activity propagation properties, when compared against a variety of alternative geometries and generative algorithms. In particular, this might help explain histological patterns of grey matter connectivity, highlighting that observed connection distances may have arisen to maximise information processing ability, and that such gains are consistent with (and enhanced by) the presence of short-cut connections

    Seroepidemiology of hepatitis B in individuals born between1945-1985 on a brazilian regional metropolis

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     Background: hepatitis B prevalence can be influenced by social/cultural behavior and the Baby Boomer (BB) generation(1945-1964) may have been more susceptible to this infection. Objectives: We investigated the seroprevalence of markers for HBV infection and vaccination and its association with main risk factors. Methodology: a random sample of individuals aged 30-70 years old in a public clinical laboratory from a metropolitan area of Bahia/Brazil were tested for HBsAg/Total Anti-HBc/Anti-HBs/Anti-HBc-IgM and a socio-demographic questionnaire was applied. Results: of the650 participants, 349 were 51-70 yo (BB) and 301 were non-BB. The prevalences were HBsAg (2.3%), Total Anti-HBc (17.1%) and Anti-HBs (27.4%). Anti-HBcIgM (2.7%) was performed in 112 participants sera who had contact/infection with HBV. The laboratory profiles were characterized as susceptibility (68%), vaccine response (14.8%) and contact/infection with HBV (17.2%). BB participants were more susceptible and less vaccinated than non-BB. The higher frequency of contact/infection status was observed in the BB generation. Statistically significant differences were found for the contact/infection status in males(50,9%) illicit drug use (11,6%), syringe/needle sharing (7,1%), and blood transfusion (10,7%). Non-BB with contact/ infection profile reported more tattoo/piercing and BB reported higher use of glass syringes. Conclusion: the majority of the study population was susceptible to infection but participants older than 50 years showed both, a higher frequency of this profile and also a higher frequency of contact/infection status, thus suggesting the need for greater health care attention for this age group

    Avaliação da resposta imune humoral em caprinos inoculados com uma vacina viva atenuada liofilizada contra Corynebacterium pseudotuberculosis.

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    Caseous Lymphadenitis (CL), also known as “mal-do-caroço”, is a disease which infects ovines and caprines and eventually humans. The aethiologic agent of this disease is the Corynebacterium pseudotuberculosis. It is a facultative intracellular pathogen of macrophages and it is phylogenetically related to Mycobacterium tuberculosis. It is a worldwide disease characterized by caseous necrotic capsule-like lesions located mainly in the external lymphonodes and lungs. The infection probably happens by the contact of healthy animals with exuding abscesses of sick ones. Some bovines have been found infected but ovines and caprines are the ones which have an economic and sanitary significance. Both sexes can develop the disease at anytime but animals older than 1 or 2 years are more frequently infected. That disease causes real harmful consequences to these animals turning into a zoopathologic barrier to its economic exploitation. Eighty percent of all caprine herds are located in Brazil’s Northeastern Region and play a special role in the economic support for its people, farmers and manufacturers. The Corynebacterium pseudotuberculosis causes high economic losses in that region. The losses range over skin and bones damages, due to abscesses, as well as lower flesh/meat and milk manufacturing production and low reproduction rates. The aim of our study was to analyze the goats humoral immune response induced by the Corynebacterium pseudotuberculosis lyophilized live vaccine. The results obtained from these experiments showed that the lyophilized vaccine results in a specific antibody production at doses as high as (or higher than) 109 bacteria cells and that the treatment used in that experiment have not caused lesions in the vaccinated animals.A linfadenite caseosa (LC), comumente chamada de mal-do-caroço, é uma doença que acomete ovinos e caprinos e tem como agente etiológico Corynebacterium pseudotuberculosis. É um patógeno intracelular facultativo de macrófagos e é filogeneticamente relacionado com Mycobacterium tuberculosis. É uma doença de ocorrência mundial, caracterizada por formação de lesões necróticas encapsuladas caseosas, localizada principalmente nos linfonodos externos e pulmões. A transmissão se dá provavelmente através da pele, pelo contato de animais sadios com animais portadores de abscessos que evoluem a supuração. Eventualmente, tem sido encontrada em bovinos, porém é em ovinos e em caprinos que assume importância econômica e sanitária. Machos e fêmeas podem apresentar a doença em qualquer estação, porém encontram-se mais doentes com o desenvolver da idade, principalmente após um a dois anos de vida. A enfermidade causa sérios prejuízos a essas espécies, constituindo uma limitação zoopatológica às suas explorações. Com cerca de 80% do rebanho nacional, a região Nordeste é a maior detentora de caprinos do Brasil, onde esses animais são essenciais ao sustento do pequeno agricultor. Corynebacterium pseudotuberculosis causa consideráveis prejuízos econômicos à região, que vão desde a condenação de pele e carcaças em razão de abscessos, até perdas em eficiência na reprodução ou na produção de carne e leite. O presente trabalho teve como objetivo avaliar em caprinos a resposta imune humoral induzida pela vacina viva liofilizada, elaborada com a cepa 1002, da Empresa Baiana de Desenvolvimento Agrícola (EBDA). Os resultados evidenciaram que o referido preparado liofilizado promove a produção de anticorpos específicos em doses iguais ou maiores do que 109 CFU e que o tratamento ministrado não provocou lesões nos animais vacinados

    Delineation of VEGF-regulated genes and functions in the cervix of pregnant rodents by DNA microarray analysis

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    <p>Abstract</p> <p>Background</p> <p>VEGF-regulated genes in the cervices of pregnant and non-pregnant rodents (rats and mice) were delineated by DNA microarray and Real Time PCR, after locally altering levels of or action of VEGF using VEGF agents, namely siRNA, VEGF receptor antagonist and mouse VEGF recombinant protein.</p> <p>Methods</p> <p>Tissues were analyzed by genome-wide DNA microarray analysis, Real-time and gel-based PCR, and SEM, to decipher VEGF function during cervical remodeling. Data were analyzed by EASE score (microarray) and ANOVA (Real Time PCR) followed by Scheffe's <it>F</it>-test for multiple comparisons.</p> <p>Results</p> <p>Of the 30,000 genes analyzed, about 4,200 genes were altered in expression by VEGF, i.e., expression of about 2,400 and 1,700 genes were down- and up-regulated, respectively. Based on EASE score, i.e., grouping of genes according to their biological process, cell component and molecular functions, a number of vascular- and non-vascular-related processes were found to be regulated by VEGF in the cervix, including immune response (including inflammatory), cell proliferation, protein kinase activity, and cell adhesion molecule activity. Of interest, mRNA levels of a select group of genes, known to or with potential to influence cervical remodeling were altered. For example, real time PCR analysis showed that levels of VCAM-1, a key molecule in leukocyte recruitment, endothelial adhesion, and subsequent trans-endothelial migration, were elevated about 10 folds by VEGF. Further, VEGF agents also altered mRNA levels of decorin, which is involved in cervical collagen fibrillogenesis, and expression of eNO, PLC and PKC mRNA, critical downstream mediators of VEGF. Of note, we show that VEGF may regulate cervical epithelial proliferation, as revealed by SEM.</p> <p>Conclusion</p> <p>These data are important in that they shed new insights in VEGF's possible roles and mechanisms in cervical events near-term, including cervical remodeling.</p

    Prevalence and incidence of iron deficiency in European community-dwelling older adults : An observational analysis of the DO-HEALTH trial

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    Background and aim Iron deficiency is associated with increased morbidity and mortality in older adults. However, data on its prevalence and incidence among older adults is limited. The aim of this study was to investigate the prevalence and incidence of iron deficiency in European community-dwelling older adults aged ≥ 70 years. Methods Secondary analysis of the DO-HEALTH trial, a 3-year clinical trial including 2157 community-dwelling adults aged ≥ 70 years from Austria, France, Germany, Portugal and Switzerland. Iron deficiency was defined as soluble transferrin receptor (sTfR) > 28.1 nmol/L. Prevalence and incidence rate (IR) of iron deficiency per 100 person-years were examined overall and stratified by sex, age group, and country. Sensitivity analysis for three commonly used definitions of iron deficiency (ferritin  1.5) were also performed. Results Out of 2157 participants, 2141 had sTfR measured at baseline (mean age 74.9 years; 61.5% women). The prevalence of iron deficiency at baseline was 26.8%, and did not differ by sex, but by age (35.6% in age group ≥ 80, 29.3% in age group 75–79, 23.2% in age group 70–74); P  1.5. Occurrences of iron deficiency were observed with IR per 100 person-years of 9.2 (95% CI 8.3–10.1) and did not significantly differ by sex or age group. The highest IR per 100 person-years was observed in Austria (20.8, 95% CI 16.1–26.9), the lowest in Germany (6.1, 95% CI 4.7–8.0). Regarding the other definitions of iron deficiency, the IR per 100 person-years was 4.5 (95% CI 4.0–4.9) for ferritin  1.5. Conclusions Iron deficiency is frequent among relatively healthy European older adults, with people aged ≥ 80 years and residence in Austria and Portugal associated with the highest risk

    Immunological properties of Oxygen-Transport Proteins: Hemoglobin, Hemocyanin and Hemerythrin

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    Heterogeneity of Microglial Activation in the Innate Immune Response in the Brain

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    The immune response in the brain has been widely investigated and while many studies have focused on the proinflammatory cytotoxic response, the brain’s innate immune system demonstrates significant heterogeneity. Microglia, like other tissue macrophages, participate in repair and resolution processes after infection or injury to restore normal tissue homeostasis. This review examines the mechanisms that lead to reduction of self-toxicity and to repair and restructuring of the damaged extracellular matrix in the brain. Part of the resolution process involves switching macrophage functional activation to include reduction of proinflammatory mediators, increased production and release of anti-inflammatory cytokines, and production of cytoactive factors involved in repair and reconstruction of the damaged brain. Two partially overlapping and complimentary functional macrophage states have been identified and are called alternative activation and acquired deactivation. The immunosuppressive and repair processes of each of these states and how alternative activation and acquired deactivation participate in chronic neuroinflammation in the brain are discussed

    Bacterial Surface Appendages Strongly Impact Nanomechanical and Electrokinetic Properties of Escherichia coli Cells Subjected to Osmotic Stress

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    The physicochemical properties and dynamics of bacterial envelope, play a major role in bacterial activity. In this study, the morphological, nanomechanical and electrohydrodynamic properties of Escherichia coli K-12 mutant cells were thoroughly investigated as a function of bulk medium ionic strength using atomic force microscopy (AFM) and electrokinetics (electrophoresis). Bacteria were differing according to genetic alterations controlling the production of different surface appendages (short and rigid Ag43 adhesins, longer and more flexible type 1 fimbriae and F pilus). From the analysis of the spatially resolved force curves, it is shown that cells elasticity and turgor pressure are not only depending on bulk salt concentration but also on the presence/absence and nature of surface appendage. In 1 mM KNO3, cells without appendages or cells surrounded by Ag43 exhibit large Young moduli and turgor pressures (∼700–900 kPa and ∼100–300 kPa respectively). Under similar ionic strength condition, a dramatic ∼50% to ∼70% decrease of these nanomechanical parameters was evidenced for cells with appendages. Qualitatively, such dependence of nanomechanical behavior on surface organization remains when increasing medium salt content to 100 mM, even though, quantitatively, differences are marked to a much smaller extent. Additionally, for a given surface appendage, the magnitude of the nanomechanical parameters decreases significantly when increasing bulk salt concentration. This effect is ascribed to a bacterial exoosmotic water loss resulting in a combined contraction of bacterial cytoplasm together with an electrostatically-driven shrinkage of the surface appendages. The former process is demonstrated upon AFM analysis, while the latter, inaccessible upon AFM imaging, is inferred from electrophoretic data interpreted according to advanced soft particle electrokinetic theory. Altogether, AFM and electrokinetic results clearly demonstrate the intimate relationship between structure/flexibility and charge of bacterial envelope and propensity of bacterium and surface appendages to contract under hypertonic conditions
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