421 research outputs found

    Novel phytoandrogens and lipidic augmenters from Eucommia ulmoides

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    BACKGROUND: Plants containing compounds such as the isoflavonoids, with female hormone-like effects that bind to human estrogen receptors, are known. But none has been previously shown to have corresponding male hormone-like effects that interact with the human androgen receptor. Here, we report that the tree bark (cortex) of the Gutta-Percha tree Eucommia ulmoides possesses bimodal phytoandrogenic and hormone potentiating effects by lipidic components. METHODS: The extracts of E. ulmoides were tested using in-vitro reporter gene bioassays and in-vivo animal studies. Key compounds responsible for the steroidogenic effects were isolated and identified using solid phase extraction (SPE), high performance liquid chromatography (HPLC), thin layer chromatography (TLC), gas chromatography-mass spectroscopy (GC-MS), electron spray ionisation-mass spectroscopy (ESI-MS) and nuclear magnetic resonance (NMR). RESULTS: The following bioactivities of E. ulmoides were found: (1) a phenomenal tripartite synergism exists between the sex steroid receptors (androgen and estrogen receptors), their cognate steroidal ligands and lipidic augmenters isolated from E. ulmoides, (2) phytoandrogenic activity of E. ulmoides was mediated by plant triterpenoids binding cognately to the androgen receptor (AR) ligand binding domain. CONCLUSION: In addition to well-known phytoestrogens, the existence of phytoandrogens is reported in this study. Furthermore, a form of tripartite synergism between sex steroid receptors, sex hormones and plant-derived lipids is described for the first time. This could have contrasting clinical applications for hypogonadal- and hyperlipidaemic-related disorders

    Plasma lipocalin-2 concentration is related to blood pressure and is increased in hypertension

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    Poster Sessions: no. P085INTRODUCTION: Lipocalin-2 is secreted by adipocytes and is upregulated in obesity. As obesity is known to be a cause of hypertension, we investigated whether the plasma level of lipocalin-2 is related to blood pressure and hypertension …postprin

    Plasma lipocalin-2 concentration is related to blood pressure and is increased in hypertension

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    Oral PresentationINTRODUCTION: Lipocalin-2 is secreted by adipocytes and is upregulated in obesity. As obesity is known to be a cause of hypertension, we investigated whether the plasma level of lipocalin-2 is related to blood pressure and hypertension. METHODS: The plasma concentration of lipocalin-2 was measured by immunoassay in 1925 subjects of …published_or_final_versionThe 17th Medical Research Conference, The University of Hong Kong, Hong Kong, 14 January 2012. In Hong Kong Medical Journal, 2012, v. 18 suppl. 1, p. 18, abstract no. 1

    Manually operated scratch tester for characterization of mechanical properties of thin films

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    Author name used in this publication: Chung Wo OngAuthor name used in this publication: Woon Ming Lau2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Strain-dependent host transcriptional responses to toxoplasma infection are largely conserved in mammalian and avian hosts

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    Toxoplasma gondii has a remarkable ability to infect an enormous variety of mammalian and avian species. Given this, it is surprising that three strains (Types I/II/III) account for the majority of isolates from Europe/North America. The selective pressures that have driven the emergence of these particular strains, however, remain enigmatic. We hypothesized that strain selection might be partially driven by adaptation of strains for mammalian versus avian hosts. To test this, we examine in vitro, strain-dependent host responses in fibroblasts of a representative avian host, the chicken (Gallus gallus). Using gene expression profiling of infected chicken embryonic fibroblasts and pathway analysis to assess host response, we show here that chicken cells respond with distinct transcriptional profiles upon infection with Type II versus III strains that are reminiscent of profiles observed in mammalian cells. To identify the parasite drivers of these differences, chicken fibroblasts were infected with individual F1 progeny of a Type II x III cross and host gene expression was assessed for each by microarray. QTL mapping of transcriptional differences suggested, and deletion strains confirmed, that, as in mammalian cells, the polymorphic rhoptry kinase ROP16 is the major driver of strain-specific responses. We originally hypothesized that comparing avian versus mammalian host response might reveal an inversion in parasite strain-dependent phenotypes; specifically, for polymorphic effectors like ROP16, we hypothesized that the allele with most activity in mammalian cells might be less active in avian cells. Instead, we found that activity of ROP16 alleles appears to be conserved across host species; moreover, additional parasite loci that were previously mapped for strain-specific effects on mammalian response showed similar strain-specific effects in chicken cells. These results indicate that if different hosts select for different parasite genotypes, the selection operates downstream of the signaling occurring during the beginning of the host's immune response. © 2011 Ong et al

    Stringy Stability of Charged Dilaton Black Holes with Flat Event Horizon

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    Electrically charged black holes with flat event horizon in anti-de Sitter space have received much attention due to various applications in Anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence, from modeling the behavior of quark-gluon plasma to superconductor. Crucial to the physics on the dual field theory is the fact that when embedded in string theory, black holes in the bulk may become vulnerable to instability caused by brane pair-production. Since dilaton arises naturally in the context of string theory, we study the effect of coupling dilaton to Maxwell field on the stability of flat charged AdS black holes. In particular, we study the stability of Gao-Zhang black holes, which are locally asymptotically anti-de Sitter. We find that for dilaton coupling parameter α\alpha > 1, flat black holes are stable against brane pair production, however for 0 < α\alpha < 1, the black holes eventually become unstable as the amount of electrical charges is increased. Such instability however, behaves somewhat differently from that of flat Reissner-Nordstr\"om black holes. In addition, we prove that the Seiberg-Witten action of charged dilaton AdS black hole of Gao-Zhang type with flat event horizon (at least in 5-dimension) is always logarithmically divergent at infinity for finite values of α\alpha, and is finite and positive in the case α\alpha tends to infinity . We also comment on the robustness of our result for other charged dilaton black holes that are not of Gao-Zhang type.Comment: Fixed some confusions regarding whether part of the discussions concern electrically charged hole or magnetically charged one. No changes to the result

    SILAC-based proteomic quantification of chemoattractant-induced cytoskeleton dynamics on a second to minute timescale

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    Cytoskeletal dynamics during cell behaviours ranging from endocytosis and exocytosis to cell division and movement is controlled by a complex network of signalling pathways, the full details of which are as yet unresolved. Here we show that SILAC-based proteomic methods can be used to characterize the rapid chemoattractant-induced dynamic changes in the actin–myosin cytoskeleton and regulatory elements on a proteome-wide scale with a second to minute timescale resolution. This approach provides novel insights in the ensemble kinetics of key cytoskeletal constituents and association of known and novel identified binding proteins. We validate the proteomic data by detailed microscopy-based analysis of in vivo translocation dynamics for key signalling factors. This rapid large-scale proteomic approach may be applied to other situations where highly dynamic changes in complex cellular compartments are expected to play a key role

    Prevalência e fatores associados de infecção pelo M. tuberculosis entre Agentes Comunitários de Saúde.

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    Introdução: A tuberculose é uma doença milenar e que, ainda hoje, constitui grave problema de saúde pública em todo o mundo. Objetivo: Estimar a prevalência e os fatores associados à infecção latente pelo MTB entre Agentes Comunitários de Saúde atuantes na rede básica de saúde de Municípios prioritários para o controle de TB Cuiabá/MT, Manaus/AM, Salvador/BA e Vitória/ES. Métodos: Estudo de corte transversal no qual os dados foram coletados através de questionário, composto de questões abertas e fechadas sobre características pessoais; informações a respeito da tuberculose; utilização de medidas preventivas, etc. Aplicou-se prova tuberculínica, com leitura após 48-72h por enfermeiros treinados, considerando como ponte de corte positivo 5 e 10 mm de enduração. A análise múltipla foi feita por meio de regressão logística hierarquica. Foram incluídas no modelo as variáveis que mostraram associação com desfecho com p<0,1. Permaneceram no modelo as variáveis independentes que mantiveram associação com desfecho após ajuste (p<0,05). Este estudo obteve aprovação do Comitê de Ética em Pesquisa com seres humanos do Centro de Ciências da Saúde da Universidade Federal do Espírito Santo, n° de registro CEP-07/2010 e das Secretarias Municipais de Saúde, por meio de uma Carta de Apresentação. Resultados: 322 Agentes Comunitários de Saúde (ACS) aceitaram participar voluntariamente do estudo por meio da assinatura do Termo de Consentimento Livre e Esclarecido. Destes, 10 não compareceram para leitura, sendo estes considerados como perdas, além do que um indivíduo foi excluído pelo fato do teste rápido para HIV ter resultado positivo, perfazendo uma amostra final de 311 participantes. Ainda em relação aos ACS triados, a positividade a Prova Tuberculínica, levando-se em consideração o ponto de corte ao teste de 10 mm e de 5 mm de enduração, foi de 37,30% (IC95%: 0,31-0,42) e de 57,88% (IC95%: 0,52-0,63), respectivamente.Conclusões: Faz-se necessário um programa de realização de Prova Tuberculínica, de rotina, combinado com intervenções para reduzir o risco de transmissão nosocomial, bem como a realização de outros estudos para avaliar a eficácia de novos testes para detecção de tuberculose latente

    Prevalence of chronic kidney disease in Thai adults: a national health survey

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    <p>Abstract</p> <p>Background</p> <p>The prevalence of patients with end stage renal disease (ESRD) who need dialysis and/or transplantation has more than doubled in Thailand during the past two decades. It has been suggested that therapeutic strategies to reduce the risk of ESRD and other complications in CKD are now available, thus the early recognition and the institution of proven therapeutic strategies are important and beneficial. We, therefore, aimed to determine the prevalence of CKD in Thai adults from the National Health Examination Survey of 2004.</p> <p>Methods</p> <p>Data from a nationally representative sample of 3,117 individuals aged 15 years and older was collected using questionnaires, physical examination and blood samples. Serum creatinine was measured by Jaffé method. GFR was estimated using the Chinese modified Modification of Diet in Renal Disease Study equation. Chronic kidney Disease (CKD) stages were classified based on Kidney Disease Outcome Quality Initiative (K/DOQI).</p> <p>Results</p> <p>The prevalence of CKD in Thai adults weighted to the 2004 Thai population by stage was 8.1% for stage 3, 0.2% and 0.15% for stage 4 and 5 respectively. Compared to non-CKD, individuals with CKD were older, had a higher level of cholesterol, and higher blood pressure. Those with cardiovascular risk factors were more likely to have CKD (stage 3-5) than those without, including hypertension (OR 1.6, 95%CI 1.1, 3.4), diabetes (OR 1.87, 95%CI 1.0, 3.4). CKD was more common in northeast (OR 2.1, 95%CI 1.3, 3.3) compared to central region. Urinalysis was not performed, therefore, we could not have data on CKD stage 1 and 2. We have no specific GFR formula for Thai population.</p> <p>Conclusion</p> <p>The identification of CKD patients should be evaluated and monitored for appropriate intervention for progression to kidney disease from this screening.</p
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