20 research outputs found

    The secreted triose phosphate isomerase of Brugia malayi is required to sustain microfilaria production in vivo

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    Human lymphatic filariasis is a major tropical disease transmitted through mosquito vectors which take up microfilarial larvae from the blood of infected subjects. Microfilariae are produced by long-lived adult parasites, which also release a suite of excretory-secretory products that have recently been subject to in-depth proteomic analysis. Surprisingly, the most abundant secreted protein of adult Brugia malayi is triose phosphate isomerase (TPI), a glycolytic enzyme usually associated with the cytosol. We now show that while TPI is a prominent target of the antibody response to infection, there is little antibody-mediated inhibition of catalytic activity by polyclonal sera. We generated a panel of twenty-three anti-TPI monoclonal antibodies and found only two were able to block TPI enzymatic activity. Immunisation of jirds with B. malayi TPI, or mice with the homologous protein from the rodent filaria Litomosoides sigmodontis, failed to induce neutralising antibodies or protective immunity. In contrast, passive transfer of neutralising monoclonal antibody to mice prior to implantation with adult B. malayi resulted in 60–70% reductions in microfilarial levels in vivo and both oocyte and microfilarial production by individual adult females. The loss of fecundity was accompanied by reduced IFNγ expression by CD4+ T cells and a higher proportion of macrophages at the site of infection. Thus, enzymatically active TPI plays an important role in the transmission cycle of B. malayi filarial parasites and is identified as a potential target for immunological and pharmacological intervention against filarial infections

    Impact of early life exposures to geohelminth infections on the development of vaccine immunity, allergic sensitization, and allergic inflammatory diseases in children living in tropical Ecuador: the ECUAVIDA birth cohort study.

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    Background Geohelminth infections are highly prevalent infectious diseases of childhood in many regions of the Tropics, and are associated with significant morbidity especially among pre-school and school-age children. There is growing concern that geohelminth infections, particularly exposures occurring during early life in utero through maternal infections or during infancy, may affect vaccine immunogenicity in populations among whom these infections are endemic. Further, the low prevalence of allergic disease in the rural Tropics has been attributed to the immune modulatory effects of these infections and there is concern that widespread use of anthelmintic treatment in high-risk groups may be associated with an increase in the prevalence of allergic diseases. Because the most widely used vaccines are administered during the first year of life and the antecedents of allergic disease are considered to occur in early childhood, the present study has been designed to investigate the impact of early exposures to geohelminths on the development of protective immunity to vaccines, allergic sensitization, and allergic disease. Methods/Design A cohort of 2,403 neonates followed up to 8 years of age. Primary exposures are infections with geohelminth parasites during the last trimester of pregnancy and the first 2 years of life. Primary study outcomes are the development of protective immunity to common childhood vaccines (i.e. rotavirus, Haemophilus influenzae type B, Hepatitis B, tetanus toxoid, and oral poliovirus type 3) during the first 5 years of life, the development of eczema by 3 years of age, the development of allergen skin test reactivity at 5 years of age, and the development of asthma at 5 and 8 years of age. Potential immunological mechanisms by which geohelminth infections may affect the study outcomes will be investigated also. Discussion The study will provide information on the potential effects of early exposures to geohelminths (during pregnancy and the first 2 years of life) on the development of vaccine immunity and allergy. The data will inform an ongoing debate of potential effects of geohelminths on child health and will contribute to policy decisions on new interventions designed to improve vaccine immunogenicity and protect against the development of allergic diseases

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    Species-specific regulation of angiogenesis by glucocorticoids reveals contrasting effects on inflammatory and angiogenic pathways

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    <div><p>Glucocorticoids are potent inhibitors of angiogenesis in the rodent <i>in vivo</i> and <i>in vitro</i> but the mechanism by which this occurs has not been determined. Administration of glucocorticoids is used to treat a number of conditions in horses but the angiogenic response of equine vessels to glucocorticoids and, therefore, the potential role of glucocorticoids in pathogenesis and treatment of equine disease, is unknown. This study addressed the hypothesis that glucocorticoids would be angiostatic both in equine and murine blood vessels.The mouse aortic ring model of angiogenesis was adapted to assess the effects of cortisol in equine vessels. Vessel rings were cultured under basal conditions or exposed to: foetal bovine serum (FBS; 3%); cortisol (600 nM), cortisol (600nM) plus FBS (3%), cortisol (600nM) plus either the glucocorticoid receptor antagonist RU486 or the mineralocorticoid receptor antagonist spironolactone. In murine aortae cortisol inhibited and FBS stimulated new vessel growth. In contrast, in equine blood vessels FBS alone had no effect but cortisol alone, or in combination with FBS, dramatically increased new vessel growth compared with controls. This effect was blocked by glucocorticoid receptor antagonism but not by mineralocorticoid antagonism. The transcriptomes of murine and equine angiogenesis demonstrated cortisol-induced down-regulation of inflammatory pathways in both species but up-regulation of pro-angiogenic pathways selectively in the horse. Genes up-regulated in the horse and down-regulated in mice were associated with the extracellular matrix. These data call into question our understanding of glucocorticoids as angiostatic in every species and may be of clinical relevance in the horse.</p></div

    Avaliação do declínio cognitivo e sua relação com as características socioeconômicas dos idosos em Viçosa-MG Evaluation of cognitive decline and its relationship with socioeconomic characteristics of the elderly in Viçosa, Minas Gerais

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    INTRODUÇÃO: Este estudo teve como objetivo avaliar o declínio cognitivo de idosos (indivíduos com 60 anos ou mais), freqüentadores do Programa Municipal da Terceira Idade (PMTI), em Viçosa, MG, e sua relação com as características socioeconômicas. MÉTODOS: Realizou-se um estudo analítico transversal com 74 idosos. Foram incluídos no estudo os idosos alfabetizados que preencheram os seguintes critérios: ausência de perda visual ou auditiva, eventualmente corrigidas, ausência de alterações motoras e paralisia nos membros superiores ou a falta deles, ausência de problemas neurológicos ou psiquiátricos que prejudicassem o desempenho no Mini-Exame do estado mental (MEEM). Os instrumentos de coleta de dados adotados foram um questionário, elaborado pela equipe de pesquisadores para a avaliação das características socioeconômicas, e o MEEM. RESULTADOS: Dentre os idosos avaliados, encontrou-se uma freqüência de declínio cognitivo de 36,5%. A média de pontuação no MEEM foi de 19,48 pontos em um total de 30 pontos e a média da idade dos idosos foi de 68,5 anos. DISCUSSÃO: Os resultados encontrados mostram que o menor nível de escolaridade tem influência negativa no estado mental dos idosos. Conclusão: Conclui-se que é alto o número de idosos identificados com declínio cognitivo. Para se concluir um diagnóstico de demência em idosos, cujas respectivas pontuações foram abaixo do determinado, é necessária uma avaliação neuropsicológica mais apurada.<br>INTRODUCTION: This study assesses cognitive decline in individuals 60 years of age and over, participants of a City Third Age Program (CPTA) in Viçosa, MG, and its relation with social and economic characteristics. METHODS: A cross-sectional analytical study was carried out with 74 elderly individuals. The study included literate individuals who filled out the following criteria: absence of visual or auditory loss, with some inclusions of corrected cases; absence of motor alterations, upper member paralysis or lack of members; absence of neurological or psychiatric problems affecting performance in the MMSE (Mini-Mental State Examination). Data collecting tools were a questionnaire prepared by the research team, and the MMSE. RESULTS: The frequency of cognitive decline was 36.5%. The average MMSE score was 19.48 points of a best total of 30, and the average age of the elderly was 68.5 years. DISCUSSION: The results showed that a lower level of schooling has a negative influence on the mental state of the elderly. CONCLUSION: A high number of elderly individuals with cognitive decline were identified, which is an unsettling factor. To conclude, the diagnosis of dementia in the elderly whose scores indicated cognitive decline needs more refined neurological and psychiatric evaluation
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