66 research outputs found

    Identification of Autotoxic Compounds in Fibrous Roots of Rehmannia (Rehmannia glutinosa Libosch.)

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    Rehmannia is a medicinal plant in China. Autotoxicity has been reported to be one of the major problems hindering the consecutive monoculture of Rehmannia. However, potential autotoxins produced by the fibrous roots are less known. In this study, the autotoxicity of these fibrous roots was investigated. Four groups of autotoxic compounds from the aqueous extracts of the fibrous roots were isolated and characterized. The ethyl acetate extracts of these water-soluble compounds were further analyzed and separated into five fractions. Among them, the most autotoxic fraction (Fr 3) was subjected to GC/MS analysis, resulting in 32 identified compounds. Based on literature, nine compounds were selected for testing their autotoxic effects on radicle growth. Seven out of the nine compounds were phenolic, which significantly reduced radicle growth in a concentration-dependent manner. The other two were aliphatic compounds that showed a moderate inhibition effect at three concentrations. Concentration of these compounds in soil samples was determined by HPLC. Furthermore, the autotoxic compounds were also found in the top soil of the commercially cultivated Rehmannia fields. It appears that a close link exists between the autotoxic effects on the seedlings and the compounds extracted from fibrous roots of Rehmannia

    Short-Term Striatal Gene Expression Responses to Brain-Derived Neurotrophic Factor Are Dependent on MEK and ERK Activation

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    BACKGROUND: Brain-derived neurotrophic factor (BDNF) is believed to be an important regulator of striatal neuron survival, differentiation, and plasticity. Moreover, reduction of BDNF delivery to the striatum has been implicated in the pathophysiology of Huntington's disease. Nevertheless, many essential aspects of BDNF responses in striatal neurons remain to be elucidated. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we assessed the relative contributions of multipartite intracellular signaling pathways to the short-term induction of striatal gene expression by BDNF. To identify genes regulated by BDNF in these GABAergic cells, we first used DNA microarrays to quantify their transcriptomic responses following 3 h of BDNF exposure. The signal transduction pathways underlying gene induction were subsequently dissected using pharmacological agents and quantitative real-time PCR. Gene expression responses to BDNF were abolished by inhibitors of TrkB (K252a) and calcium (chelator BAPTA-AM and transient receptor potential cation channel [TRPC] antagonist SKF-96365). Interestingly, inhibitors of mitogen-activated protein kinase kinases 1 and 2 (MEK1/2) and extracellular signal-regulated kinase ERK also blocked the BDNF-mediated induction of all tested BDNF-responsive genes. In contrast, inhibitors of nitric oxide synthase (NOS), phosphotidylinositol-3-kinase (PI3K), and CAMK exhibited less prevalent, gene-specific effects on BDNF-induced RNA expression. At the nuclear level, the activation of both Elk-1 and CREB showed MEK dependence. Importantly, MEK-dependent activation of transcription was shown to be required for BDNF-induced striatal neurite outgrowth, providing evidence for its contribution to striatal neuron plasticity. CONCLUSIONS: These results show that the MEK/ERK pathway is a major mediator of neuronal plasticity and other important BDNF-dependent striatal functions that are fulfilled through the positive regulation of gene expression

    Man and the Last Great Wilderness: Human Impact on the Deep Sea

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    The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life – SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO2 and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO2 and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short discussion on protection and management methods

    Transfusions after nonmyeloablative or reduced-intensity conditioning regimens.

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    Allogeneic hematopoietic cell transplantation (HCT) following reduced-intensity conditioning (RIC) or nonmyeloablative con-ditioning has been an effective treatment for many patients with hematological malignancies, as well as for selected patient

    Experimental Identification of Actinobacillus pleuropneumoniae Strains L20 and JL03 Heptosyltransferases, Evidence for a New Heptosyltransferase Signature Sequence.

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    We experimentally identified the activities of six predicted heptosyltransferases in Actinobacillus pleuropneumoniae genome serotype 5b strain L20 and serotype 3 strain JL03. The initial identification was based on a bioinformatic analysis of the amino acid similarity between these putative heptosyltrasferases with others of known function from enteric bacteria and Aeromonas. The putative functions of all the Actinobacillus pleuropneumoniae heptosyltrasferases were determined by using surrogate LPS acceptor molecules from well-defined A. hydrophyla AH-3 and A. salmonicida A450 mutants. Our results show that heptosyltransferases APL_0981 and APJL_1001 are responsible for the transfer of the terminal outer core D-glycero-D-manno-heptose (D,D-Hep) residue although they are not currently included in the CAZY glycosyltransferase 9 family. The WahF heptosyltransferase group signature sequence [S(T/S)(GA)XXH] differs from the heptosyltransferases consensus signature sequence [D(TS)(GA)XXH], because of the substitution of D(261) for S(261), being unique

    Transtornos depressivos em crianças com leucemia linfoide aguda e com insuficiência renal crônica terminal: estudo de série de casos Depressive disease in children with acute lymphocytic leukemia and end stage of renal disease: case series study

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    OBJETIVO: Investigar a presença de transtornos depressivos em crianças portadoras de leucemia linfoide aguda (LLA) e insuficiência renal crônica terminal (IRCT) atendidas no IMIP. MÉTODO: Estudo descritivo do tipo série de casos, composto por 52 crianças entre 8 e 15 anos portadoras de LLA e de IRCT. RESULTADOS: Três (5,8%) casos preenchiam os critérios para episódio depressivo maior (EDM), sendo dois portadores de IRCT e um portador de LLA. Oito (15,4%) preenchiam os critérios para transtorno distímico (TD), todos eles portadores de IRCT. A associação entre faixa etária e EDM não foi significativa (p=0,327). Entretanto, a faixa etária foi significante em relação ao TD (p=0,014), todos os seus portadores tinham entre 12 e 15 anos de idade. A associação entre os transtornos depressivos e o tempo de evolução da doença de base não foi significante. Contudo, observou-se uma tendência a quanto maior o tempo de evolução da doença de base, maior a associação com o TD. CONCLUSÃO: A frequência de EDM ficou dentro da faixa encontrada na literatura para escolares saudáveis, entretanto, a de TD foi mais alta. Não foram encontradas diferenças significantes entre as faixas etárias no diagnóstico de EDM. Porém, corroborando a literatura, a faixa etária maior prevaleceu em relação ao TD.<br>OBJECTIVE: To Investigate the presence of depressive disease in children with acute lymphocytic leukemia (ALL) and end stage of renal disease (ESRD). METHOD: A case series study including 52 children suffering of ALL or ESRD aged 8 to 15 years. RESULTS: Three patients (5.8%) had major depressive episode (MDE), two of them with ESRD and one with ALL. Eight patients (15.4%) had dysthymic disorder (DD), all of them had ESRD. The association between age and MDE was not meaningful. On other hand, the association between age and DD was significant, and all of the patients aged between 12 and 15 years. The association between depressive diseases and evolution time of base disease was not significant. However, it was observed that the bigger the time of base disease evolution, the bigger the association with DD. CONCLUSION: The frequency of MED was not different from the literature, but the frequency of DD was higher. In opposition to what was expected, there wasn't difference between the ages in MED. However, in agreement with the literature, it prevailed the highest ages in DD
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