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41.
We report here the isolation and identification of the RNA specifically immunoprecipitated and covalently linked to the tumor suppressor gene product p53. After treatment with proteinase K, the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) band of p53 yields a single, discrete 157-nucleotide RNA, which was cloned, sequenced, and identified as 5.8S rRNA. 5.8S rRNA was obtained only after proteolysis of the p53 SDS-PAGE band. Free 5.8S rRNA did not comigrate with p53 in SDS-PAGE. This RNA was only immunoprecipitated from cells containing p53. Protein-free RNA obtained by proteolysis of the p53 band hybridized to the single-stranded DNA vector containing the antisense sequence of 5.8S rRNA. The covalence of the p53-5.8S rRNA linkage was demonstrated by the following findings: (i) p53 and the linked 5.8S rRNA comigrated in SDS-PAGE; (ii) only after treatment of the p53-RNA complex with proteinase K did the 5.8S rRNA migrate differently from p53-linked 5.8S rRNA; and (iii) this isolated RNA was found linked to phosphoserine, presumably at the 5' end. Covalent linkage to the single, specific RNA suggests that p53 may be involved in regulating the expression or function of 5.8S rRNA. 相似文献
42.
Isabela Lopes Trevizan Talita Dias Silva Helen Dawes Thais Massetti Tânia Brusque Crocetta Francis Meire Favero Acary Souza Bulle Oliveira Luciano Vieira de Araújo Ana Carolina Costa Santos Luiz Carlos de Abreu Shelly Coe Carlos Bandeira de Mello Monteiro 《BMC neurology》2018,18(1):209
Background
Amyotrophic Lateral Sclerosis (ALS) is a rapid progressive neurodegenerative disease, characterized by a selective loss of motor neurons, brain stem and spinal cord which leads to deterioration of motor abilities. Devices that promote interaction with tasks on computers can enhance performance and lead to greater independence and utilization of technology.Objective
To evaluate performance on a computer task in individuals with ALS using three different commonly used non-immersive devices.Method
Thirty individuals with ALS (18 men and 12 women, mean age 59?years, range 44–74?years) with a mean score of 26, (minimum score of 14 and maximum 41) on the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) and 30 healthy controls matched for age and gender, participated. All participants were randomly divided into three groups, each using a different device system (motion tracking, finger motion control or touchscreen) to perform three task phases (acquisition, retention and transfer).Results
Both the ALS and control group (CG) showed better performance on the computer task when using the touchscreen device, but there was limited transfer of performance onto the task performed on the Finger Motion control or motion tracking. However, we found that using the motion tracking device led to transfer of performance to the touchscreen.Conclusion
This study presents novel and important findings when selecting interaction devices for individuals with ALS to access technology by demonstrating immediate performance benefits of using a touchscreen device, such as improvement of motor skills. There were possible transferable skills obtained when using virtual systems which may allow flexibility and enable individuals to maintain performance overtime.Trial registration
Registration name: Virtual Task in Amyotrophic Lateral Sclerosis; Registration number: NCT03113630; retrospectively registered on 04/13/2017. Date of enrolment of the first participant to the trial: 02/02/2016.43.
Land use change emission scenarios: anticipating a forest transition process in the Brazilian Amazon 总被引:1,自引:0,他引:1 下载免费PDF全文
Ana Paula Dutra Aguiar Ima Célia Guimarães Vieira Talita Oliveira Assis Eloi L Dalla‐Nora Peter Mann Toledo Roberto Araújo Oliveira Santos‐Junior Mateus Batistella Andrea Santos Coelho Elza Kawakami Savaget Luiz Eduardo Oliveira Cruz Aragão Carlos Afonso Nobre Jean Pierre H. Ometto 《Global Change Biology》2016,22(5):1821-1840
Following an intense occupation process that was initiated in the 1960s, deforestation rates in the Brazilian Amazon have decreased significantly since 2004, stabilizing around 6000 km2 yr?1 in the last 5 years. A convergence of conditions contributed to this, including the creation of protected areas, the use of effective monitoring systems, and credit restriction mechanisms. Nevertheless, other threats remain, including the rapidly expanding global markets for agricultural commodities, large‐scale transportation and energy infrastructure projects, and weak institutions. We propose three updated qualitative and quantitative land‐use scenarios for the Brazilian Amazon, including a normative ‘Sustainability’ scenario in which we envision major socio‐economic, institutional, and environmental achievements in the region. We developed an innovative spatially explicit modelling approach capable of representing alternative pathways of the clear‐cut deforestation, secondary vegetation dynamics, and the old‐growth forest degradation. We use the computational models to estimate net deforestation‐driven carbon emissions for the different scenarios. The region would become a sink of carbon after 2020 in a scenario of residual deforestation (~1000 km2 yr?1) and a change in the current dynamics of the secondary vegetation – in a forest transition scenario. However, our results also show that the continuation of the current situation of relatively low deforestation rates and short life cycle of the secondary vegetation would maintain the region as a source of CO2 – even if a large portion of the deforested area is covered by secondary vegetation. In relation to the old‐growth forest degradation process, we estimated average gross emission corresponding to 47% of the clear‐cut deforestation from 2007 to 2013 (using the DEGRAD system data), although the aggregate effects of the postdisturbance regeneration can partially offset these emissions. Both processes (secondary vegetation and forest degradation) need to be better understood as they potentially will play a decisive role in the future regional carbon balance. 相似文献
44.
Talita O. Araújo Samara Arcanjo‐Silva Larisse Freitas‐Silva Aristéa A. Azevedo Adriano Nunes‐Nesi 《Physiologia plantarum》2016,157(2):135-146
Arsenic (As) pollution is a major environmental concern due to its worldwide distribution and high toxicity to organisms. The fern Pityrogramma calomelanos is one of the few plant species known to be able to hyperaccumulate As, although the mechanisms involved are largely unknown. This study aimed to investigate the metabolic adjustments involved in the As‐tolerance of P. calomelanos. For this purpose, ferns with five to seven fronds were exposed to a series of As concentrations. Young fronds were used for biochemical analysis and metabolite profiling using gas chromatography–mass spectrometry. As treatment increased the total concentration of proteins and soluble phenols, enhanced peroxidase activities, and promoted disturbances in nitrogen and carbon metabolism. The reduction of the glucose pool was one of the striking responses to As. Remarkable changes in amino acids levels were observed in As‐treated plants, including those related to biosynthesis of glutathione and phenols, osmoregulation and two photorespiratory intermediates. In addition, increases in polyamines levels and antioxidant enzyme activities were observed. In summary, this study indicates that P. calomelanos tolerates high concentration of As due to its capacity to upregulate biosynthesis of amino acids and antioxidants, without greatly disturbing central carbon metabolism. At extremely high As concentrations, however, this protective mechanism fails to block reactive oxygen species production, leading to lipid peroxidation and leaf necrosis. 相似文献
45.
Constantinos Kurt Wibmer Jason Gorman Colin S. Anthony Nonhlanhla N. Mkhize Aliaksandr Druz Talita York Stephen D. Schmidt Phillip Labuschagne Mark K. Louder Robert T. Bailer Salim S. Abdool Karim John R. Mascola Carolyn Williamson Penny L. Moore Peter D. Kwong Lynn Morris 《Journal of virology》2016,90(22):10220-10235
46.
Min Zhang Satish Mishra Ramanavelan Sakthivel Beatriz M. A. Fontoura Victor Nussenzweig 《PLoS pathogens》2016,12(1)
Plasmodium salivary sporozoites are the infectious form of the malaria parasite and are dormant inside salivary glands of Anopheles mosquitoes. During dormancy, protein translation is inhibited by the kinase UIS1 that phosphorylates serine 59 in the eukaryotic initiation factor 2α (eIF2α). De-phosphorylation of eIF2α-P is required for the transformation of sporozoites into the liver stage. In mammalian cells, the de-phosphorylation of eIF2α-P is mediated by the protein phosphatase 1 (PP1). Using a series of genetically knockout parasites we showed that in malaria sporozoites, contrary to mammalian cells, the eIF2α-P phosphatase is a member of the PP2C/PPM phosphatase family termed UIS2. We found that eIF2α was highly phosphorylated in uis2 conditional knockout sporozoites. These mutant sporozoites maintained the crescent shape after delivery into mammalian host and lost their infectivity. Both uis1 and uis2 were highly transcribed in the salivary gland sporozoites but uis2 expression was inhibited by the Pumilio protein Puf2. The repression of uis2 expression was alleviated when sporozoites developed into liver stage. While most eukaryotic phosphatases interact transiently with their substrates, UIS2 stably bound to phosphorylated eIF2α, raising the possibility that high-throughput searches may identify chemicals that disrupt this interaction and prevent malaria infection. 相似文献
47.
48.
Talita Caroline Hereman Maria do Carmo Bittencourt‐Oliveira 《Journal of phycology》2012,48(6):1535-1537
The contamination of lettuce (Lactuca sativa L.) by water‐borne crude extracts of the cyanobacterium microcystin‐producing Microcystis aeruginosa (Kützing) Kützing was investigated. The aim of the study was to determine whether bioaccumulation of microcystins occurs in lettuce foliar tissue when sprayed with solutions containing microcystins at concentrations observed in aquatic systems (0.62 to 12.5 μg · L?1). Microcystins were found in lettuce foliar tissues (8.31 to 177.8 μg per Kg of fresh weight) at all concentrations of crude extracts. Spraying with water containing microcystins and cyanobacteria may contaminate lettuce at levels higher than the daily intake of microcystins recommended by the World Health Organization (WHO), underscoring the need to monitor such food exposure pathways by public authorities. 相似文献
49.
Moraes JC Amaral ME Picardi PK Calegari VC Romanatto T Bermúdez-Echeverry M Chiavegatto S Saad MJ Velloso LA 《FEBS letters》2006,580(19):4625-4631
TNF-alpha acts on the hypothalamus modulating food intake and energy expenditure through mechanisms incompletely elucidated. Here, we explore the hypothesis that, to modulate insulin-induced anorexigenic signaling in hypothalamus, TNF-alpha requires the synthesis of NO. TNF-alpha activates signal transduction through JNK and p38 in hypothalamus, peaking at 10(-8) M. This is accompanied by the induction of expression of the inducible and neuronal forms of NOS, in both cases peaking at 10(-12) M. In addition, TNF-alpha stimulates NOS catalytic activity. Pre-treatment with TNF-alpha at a low dose (10(-12) M) inhibits insulin-dependent anorexigenic signaling, and this effect is abolished in iNOS but not in nNOS knockout mice. 相似文献
50.
Côrtes DF Carneiro MB Santos LM Souza TC Maioli TU Duz AL Ramos-Jorge ML Afonso LC Carneiro C Vieira LQ 《Memórias do Instituto Oswaldo Cruz》2010,105(6):736-745
A model of skin infection with Leishmania amazonensis with low doses of parasites is compared to infection with high doses of L. amazonensis and low and high doses of Leishmania major. C57BL/6 mice were infected with 103 or 10(6) parasites in the ear and the outcome of infection was assessed. The appearance of lesions in mice infected with 103 parasites was delayed compared to mice infected with 10(6) Leishmania and parasites were detectable at the infection site before lesions became apparent. Mice infected with L. amazonensis displayed persistent lesions, whereas infection with L. major spontaneously healed in all groups, although lymphocytes persisted at the site of infection after healing. Macrophages persisted only in L. amazonensis-infected mice. High-dose L. amazonensis-infected mice produced lower levels of IFN-γ and TNF than mice infected with L. major. No correlation between the persistence of parasites and IL-10 levels and the production of nitric oxide or urea by macrophages was found. We conclude that infection with low doses of L. amazonensis in the dermis changes the course of infection by delaying the appearance of lesions. However, low-dose infection does not change the outcomes of susceptibility and cytokine production described for subcutaneous infection with high numbers of parasites. 相似文献