100 research outputs found

    The Impact of Venous Thromboembolism on Risk of Death or Hemorrhage in Older Cancer Patients

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    BACKGROUND: Among older cancer patients, there is uncertainty about the degree to which venous thromboembolism (VTE) and its treatment increase the risk of death or major hemorrhage. OBJECTIVE: To determine the prevalence of VTE in a cohort of older cancer patients, as well as the degree to which VTE increased the risk of death or major hemorrhage. METHODS: We conducted a retrospective cohort study of linked Surveillance, Epidemiology, and End Results cancer registry and Medicare administrative claims data. Patients with any of ten invasive cancers diagnosed during 1995 through 1999 were included; the independent variable was VTE diagnosed concomitantly with cancer diagnosis. Outcomes included major hemorrhage during the first year after cancer diagnosis and all-cause mortality; RESULTS: Overall, about 1% of patients who were diagnosed with cancer also had a VTE diagnosed concomitantly. After adjusting for sociodemographic factors and cancer stage and grade, concomitant VTE was associated with a relative increase in the risk of death for 8 of the 10 cancer types; the increase in risk tended to range 20–40% across most cancer types. Approximately 16.8% (95% confidence interval [CI] 14.9–18.8%) of patients with a concomitant VTE and 7.9% (95% CI 7.7–8.0%) of patients without a VTE experienced a major hemorrhage during the year after cancer diagnosis (P value <.001). The excess risk of hemorrhage associated with VTE varied substantially across cancer types, ranging from no significant excess (kidney and uterine cancer) to 11.5% (lymphoma). CONCLUSION: Concomitant VTE is not only a marker and potential mediator of increased risk of death among older cancer patients, but patients with a VTE have a marked increased risk of major hemorrhage

    e-Science and biological pathway semantics

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    <p>Abstract</p> <p>Background</p> <p>The development of e-Science presents a major set of opportunities and challenges for the future progress of biological and life scientific research. Major new tools are required and corresponding demands are placed on the high-throughput data generated and used in these processes. Nowhere is the demand greater than in the semantic integration of these data. Semantic Web tools and technologies afford the chance to achieve this semantic integration. Since pathway knowledge is central to much of the scientific research today it is a good test-bed for semantic integration. Within the context of biological pathways, the BioPAX initiative, part of a broader movement towards the standardization and integration of life science databases, forms a necessary prerequisite for its successful application of e-Science in health care and life science research. This paper examines whether BioPAX, an effort to overcome the barrier of disparate and heterogeneous pathway data sources, addresses the needs of e-Science.</p> <p>Results</p> <p>We demonstrate how BioPAX pathway data can be used to ask and answer some useful biological questions. We find that BioPAX comes close to meeting a broad range of e-Science needs, but certain semantic weaknesses mean that these goals are missed. We make a series of recommendations for re-modeling some aspects of BioPAX to better meet these needs.</p> <p>Conclusion</p> <p>Once these semantic weaknesses are addressed, it will be possible to integrate pathway information in a manner that would be useful in e-Science.</p

    Speed has an effect on multiple-object tracking independently of the number of close encounters between targets and distractors

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    Multiple-object tracking (MOT) studies have shown that tracking ability declines as object speed increases. However, this might be attributed solely to the increased number of times that target and distractor objects usually pass close to each other (“close encounters”) when speed is increased, resulting in more target–distractor confusions. The present study investigates whether speed itself affects MOT ability by using displays in which the number of close encounters is held constant across speeds. Observers viewed several pairs of disks, and each pair rotated about the pair’s midpoint and, also, about the center of the display at varying speeds. Results showed that even with the number of close encounters held constant across speeds, increased speed impairs tracking performance, and the effect of speed is greater when the number of targets to be tracked is large. Moreover, neither the effect of number of distractors nor the effect of target–distractor distance was dependent on speed, when speed was isolated from the typical concomitant increase in close encounters. These results imply that increased speed does not impair tracking solely by increasing close encounters. Rather, they support the view that speed affects MOT capacity by requiring more attentional resources to track at higher speeds

    piggyBac is an effective tool for functional analysis of the Plasmodium falciparum genome

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    <p>Abstract</p> <p>Background</p> <p>Much of the <it>Plasmodium falciparum </it>genome encodes hypothetical proteins with limited homology to other organisms. A lack of robust tools for genetic manipulation of the parasite limits functional analysis of these hypothetical proteins and other aspects of the <it>Plasmodium </it>genome. Transposon mutagenesis has been used widely to identify gene functions in many organisms and would be extremely valuable for functional analysis of the <it>Plasmodium </it>genome.</p> <p>Results</p> <p>In this study, we investigated the lepidopteran transposon, <it>piggyBac</it>, as a molecular genetic tool for functional characterization of the <it>Plasmodium falciparum </it>genome. Through multiple transfections, we generated 177 unique <it>P. falciparum </it>mutant clones with mostly single <it>piggyBac </it>insertions in their genomes. Analysis of <it>piggyBac </it>insertion sites revealed random insertions into the <it>P. falciparum </it>genome, in regards to gene expression in parasite life cycle stages and functional categories. We further explored the possibility of forward genetic studies in <it>P. falciparum </it>with a phenotypic screen for attenuated growth, which identified several parasite genes and pathways critical for intra-erythrocytic development.</p> <p>Conclusion</p> <p>Our results clearly demonstrate that <it>piggyBac </it>is a novel, indispensable tool for forward functional genomics in <it>P. falciparum </it>that will help better understand parasite biology and accelerate drug and vaccine development.</p

    Diversity and dynamics of bacterial communities in early life stages of the Caribbean coral Porites astreoides

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    In this study, we examine microbial communities of early developmental stages of the coral Porites astreoides by sequence analysis of cloned 16S rRNA genes, terminal restriction fragment length polymorphism (TRFLP), and fluorescence in situ hybridization (FISH) imaging. Bacteria are associated with the ectoderm layer in newly released planula larvae, in 4-day-old planulae, and on the newly forming mesenteries surrounding developing septa in juvenile polyps after settlement. Roseobacter clade-associated (RCA) bacteria and Marinobacter sp. are consistently detected in specimens of P. astreoides spanning three early developmental stages, two locations in the Caribbean and 3 years of collection. Multi-response permutation procedures analysis on the TRFLP results do not support significant variation in the bacterial communities associated with P. astreoides larvae across collection location, collection year or developmental stage. The results are the first evidence of vertical transmission (from parent to offspring) of bacteria in corals. The results also show that at least two groups of bacterial taxa, the RCA bacteria and Marinobacter, are consistently associated with juvenile P. astreoides against a complex background of microbial associations, indicating that some components of the microbial community are long-term associates of the corals and may impact host health and survival

    Small group interventions for children aged 5-9 years old with mathematical learning difficulties

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    The research related to educational interventions for children with mathematical learning difficulties has been increasing steadily. In this chapter I focus on small group interventions for children aged 5–9 years old with learning difficulties in mathematics. First, I describe the important issues: (1) who are the children having problems in mathematics, (2) what do we mean with (special) education intervention, (3) what does Responsiveness to Intervention mean, and (4) what intervention features have been found effective for children aged 5–9 years with learning difficulties in mathematics. Then, I describe the research and developmental work that has been done in Finland on designing web services which provide evidence-based information and materials for educators. The two web services are LukiMat and ThinkMath. Together, these two web services include the knowledge base, assessment batteries and intervention tools to be used in relation to mathematical learning difficulties in the age group 5–9 years.Peer reviewe

    Different contribution of BRINP3 gene in chronic periodontitis and peri-implantitis: A cross-sectional study

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    Background: Peri-implantitis is a chronic inflammation, resulting in loss of supporting bone around implants. Chronic periodontitis is a risk indicator for implant failure. Both diseases have a common etiology regarding inflammatory destructive response. BRINP3 gene is associated with aggressive periodontitis. However, is still unclear if chronic periodontitis and peri-implantitis have the same genetic background. The aim of this work was to investigate the association between BRINP3 genetic variation (rs1342913 and rs1935881) and expression and susceptibility to both diseases. Methods: Periodontal and peri-implant examinations were performed in 215 subjects, divided into: healthy (without chronic periodontitis and peri-implantitis, n = 93); diseased (with chronic periodontitis and peri-implantitis, n = 52); chronic periodontitis only (n = 36), and peri-implantitis only (n = 34). A replication sample of 92 subjects who lost implants and 185 subjects successfully treated with implants were tested. DNA was extracted from buccal cells. Two genetic markers of BRINP3 (rs1342913 and rs1935881) were genotyped using TaqMan chemistry. Chi-square (p<0.05) compared genotype and allele frequency between groups. A subset of subjects (n = 31) had gingival biopsies harvested. The BRINP3 mRNA levels were studied by CT method (2δδCT). Mann-Whitney test correlated the levels of BRINP3 in each group (p<0.05). Results: Statistically significant association between BRINP3 rs1342913 and peri-implantitis was found in both studied groups (p<0.04). The levels of BRINP3 mRNA were significantly higher in diseased subjects compared to healthy individuals (p<0.01). Conclusion: This study provides evidence that the BRINP3 polymorphic variant rs1342913 and low level of BRINP3 expression are associated with peri-implantitis, independently from the presence of chronic periodontitis

    Hypolithic microbial communities of quartz rocks from Miers Valley, McMurdo Dry Valleys, Antarctica

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    The McMurdo Dry Valleys region of eastern Antarctica is a cold desert that presents extreme challenges to life. Hypolithic microbial colonisation of the subsoil surfaces of translucent quartz rocks represent a significant source of terrestrial biomass and productivity in this region. Previous studies have described hypoliths as dominated by cyanobacteria. However, hypoliths that occur in the lower Dry Valleys such as the Miers, Garwood and Marshall Valleys are unusual as they are not necessarily cyanobacteria-dominated. These hypoliths support significant eukaryal colonisation by fungi and mosses in addition to cyanobacteria-dominated bacterial assemblages and so have considerable ecological value in this barren landscape. Here, we characterise these novel hypoliths by analysis of environmental rRNA gene sequences. The hypolithic community was demonstrated to be distinct from the surrounding soil and non-translucent rocks. Hypoliths supported cyanobacterial signatures from the Oscillatoriales and Nostocales. Other heterotrophic bacterial signatures were also recovered, and these were phylogenetically diverse and spanned 8 other bacterial phyla. Archaeal phylotypes recovered were phylogenetically affiliated with the large group of unclassified, uncultured Crenarcheota. Eukaryal phylotypes indicated that free-living ascomycetous fungi, chlorophytes and mosses (Bryum sp.) were all supported by these hypoliths, and these are thought to be responsible for the extensive eukaryotic biomass that develops around quartz rocks. © 2011 Springer-Verlag.link_to_subscribed_fulltex
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