941 research outputs found

    Phosphate regulates expression of SIBLINGs and MMPs in cementoblasts

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    Introduction: Cementoblasts, the cells responsible for tooth root cementum formation, are especially sensitive to local phosphate and pyrophosphate during development, as evidenced by cementum phenotypes resulting from altered phosphate/pyrophosphate distribution. SIBLING family members BSP, OPN, and DMP-1 are regulated by phosphate in cementoblasts and have been shown to activate three specific matrix metalloproteinase (MMP) partners: MMP2, MMP3, and MMP9, respectively, in vitro. The aim of this study was to examine regulatory effects of phosphate on SIBLING and MMP expression in cementoblasts, in vitro. Materials & Methods: Immortalized murine cementoblasts were treated with inorganic phosphate, in vitro, and effects on gene expression (by real time RT-PCR and mouse total genome microarray) were observed. Dose-response 80.1-10 mM phosphate) and time-course (1-48hr) assays were performed. A sodium-phosphate uptake inhibitor, foscarnet, was used to better define phosphate-mediated effects on cells. Results: Three SIBLING family members were regulated by phosphate: OPN (increased over 3000f control), DMP-1 (increased over 3,00027777701060f control), and BSP (decreased). MMP3 was dramatically increased (4,00026651125000f control), paralleling regulation of its partner OPN. Both MMP2 and MMP9 were slightly down-regulated. Time-course experiments indicated a response for SIBLING and MMP genes within 24 hr. Use of foscarnet demonstrated that phosphate uptake was required for observed changes in gene expression. Discussion: These results indicate an effect of phosphate on cementoblast SIBLING and MMP expression in vitro. During cementum formation, phosphate may be an important regulator of cementoblast activity, including modulation of biomineralization, attachment, and matrix modification

    Suture Materials, 1980s: Properties, Uses, and Abuses

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66057/1/j.1365-4362.1982.tb03154.x.pd

    Dioxin Toxicity In Vivo Results from an Increase in the Dioxin-Independent Transcriptional Activity of the Aryl Hydrocarbon Receptor

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    The Aryl hydrocarbon receptor (Ahr) is the nuclear receptor mediating the toxicity of dioxins -widespread and persistent pollutants whose toxic effects include tumor promotion, teratogenesis, wasting syndrome and chloracne. Elimination of Ahr in mice eliminates dioxin toxicity but also produces adverse effects, some seemingly unrelated to dioxin. Thus the relationship between the toxic and dioxin-independent functions of Ahr is not clear, which hampers understanding and treatment of dioxin toxicity. Here we develop a Drosophila model to show that dioxin actually increases the in vivo dioxin-independent activity of Ahr. This hyperactivation resembles the effects caused by an increase in the amount of its dimerisation partner Ahr nuclear translocator (Arnt) and entails an increased transcriptional potency of Ahr, in addition to the previously described effect on nuclear translocation. Thus the two apparently different functions of Ahr, dioxin-mediated and dioxin-independent, are in fact two different levels (hyperactivated and basal, respectively) of a single function

    Postcopulatory sexual selection

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    The female reproductive tract is where competition between the sperm of different males takes place, aided and abetted by the female herself. Intense postcopulatory sexual selection fosters inter-sexual conflict and drives rapid evolutionary change to generate a startling diversity of morphological, behavioural and physiological adaptations. We identify three main issues that should be resolved to advance our understanding of postcopulatory sexual selection. We need to determine the genetic basis of different male fertility traits and female traits that mediate sperm selection; identify the genes or genomic regions that control these traits; and establish the coevolutionary trajectory of sexes

    A mathematical modelling tool for predicting survival of individual patients following resection of glioblastoma: a proof of principle

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    The prediction of the outcome of individual patients with glioblastoma would be of great significance for monitoring responses to therapy. We hypothesise that, although a large number of genetic-metabolic abnormalities occur upstream, there are two ‘final common pathways' dominating glioblastoma growth – net rates of proliferation (ρ) and dispersal (D). These rates can be estimated from features of pretreatment MR images and can be applied in a mathematical model to predict tumour growth, impact of extent of tumour resection and patient survival. Only the pre-operative gadolinium-enhanced T1-weighted (T1-Gd) and T2-weighted (T2) volume data from 70 patients with previously untreated glioblastoma were used to derive a ratio D/ρ for each patient. We developed a ‘virtual control' for each patient with the same size tumour at the time of diagnosis, the same ratio of net invasion to proliferation (D/ρ) and the same extent of resection. The median durations of survival and the shapes of the survival curves of actual and ‘virtual' patients subjected to biopsy or subtotal resection (STR) superimpose exactly. For those actually receiving gross total resection (GTR), as shown by post-operative CT, the actual survival curve lies between the ‘virtual' results predicted for 100 and 125% resection of the T1-Gd volume. The concordance between predicted (virtual) and actual survivals suggests that the mathematical model is realistic enough to allow precise definition of the effectiveness of individualised treatments and their site(s) of action on proliferation (ρ) and/or dispersal (D) of the tumour cells without knowledge of any other clinical or pathological information

    Identification of Fast-Evolving Genes in the Scleractinian Coral Acropora Using Comparative EST Analysis

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    To identify fast-evolving genes in reef-building corals, we performed direct comparative sequence analysis with expressed sequence tag (EST) datasets from two acroporid species: Acropora palmata from the Caribbean Sea and A. millepora from the Great Barrier Reef in Australia. Comparison of 589 independent sequences from 1,421 A. palmata contigs, with 10,247 A. millepora contigs resulted in the identification of 196 putative homologues. Most of the homologous pairs demonstrated high amino acid similarities (over 90%). Comparisons of putative homologues showing low amino acid similarities (under 90%) among the Acropora species to the near complete datasets from two other cnidarians (Hydra magnipapillata and Nematostella vectensis) implied that some were non-orthologous. Within 86 homologous pairs, 39 exhibited dN/dS ratios significantly less than 1, suggesting that these genes are under purifying selection associated with functional constraints. Eight independent genes showed dN/dS ratios exceeding 1, while three deviated significantly from 1, suggesting that these genes may play important roles in the adaptive evolution of Acropora. Our results also indicated that CEL-III lectin was under positive selection, consistent with a possible role in immunity or symbiont recognition. Further studies are needed to clarify the possible functions of the genes under positive selection to provide insight into the evolutionary process of corals

    Brain energy metabolism: A roadmap for future research

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    Although we have learned much about how the brain fuels its functions over the last decades, there remains much still to discover in an organ that is so complex. This article lays out major gaps in our knowledge of interrelationships between brain metabolism and brain function, including biochemical, cellular, and subcellular aspects of functional metabolism and its imaging in adult brain, as well as during development, aging, and disease. The focus is on unknowns in metabolism of major brain substrates and associated transporters, the roles of insulin and of lipid droplets, the emerging role of metabolism in microglia, mysteries about the major brain cofactor and signaling molecule NAD+, as well as unsolved problems underlying brain metabolism in pathologies such as traumatic brain injury, epilepsy, and metabolic downregulation during hibernation. It describes our current level of understanding of these facets of brain energy metabolism as well as a roadmap for future research

    The Hordaland Women's Cohort: A prospective cohort study of incontinence, other urinary tract symptoms and related health issues in middle-aged women

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    <p>Abstract</p> <p>Background</p> <p>Urinary incontinence (UI) is a prevalent symptom in middle-aged women, but data on incidence is limited and rarely reported. In order to analyze incidence, remission, or development patterns of severity and types of UI, we have established a 15-year prospective cohort (1997–2012).</p> <p>Methods</p> <p>The Cohort is based on the national collection of health data gathered from county studies (CONOR). Hordaland Health Study (HUSK) is one of them from Hordaland County. Each of the county studies may have local sub-studies and our Cohort is one of them. The Cohort included women aged 40–45 in order to have a broad approach to women's health including UI and other lower urinary tract symptoms (LUTS). A onefifth random sampling from HUSK was used to create the Cohort in 1997–1999. For the necessary sample size a preliminary power calculation, based on a 70% response rate at inclusion and 5% annual attrition rates was used. The Cohort is planned to collect data through questionnaires every second year for the 15-year period from 1997–2012.</p> <p>Discussion</p> <p>The Cohort represents a relatively large random sample (N = 2,230) of about 15% of the total population of women born between 1953–57 in the county of Hordaland. Our data shows that the cohort population is very similar to the source population. The baseline demographic, social and medical characteristics of the Cohort are compared with the rest of women in HUSK (N = 7,746) and there were no significant differences between them except for the level of education (P = 0.001) and yearly income (P = 0.018), which were higher in the Cohort population. Urological characteristics of participants from the Cohort (N = 1,920) were also compared with the other participants (N = 3,400). There were no significant statistical differences except for somewhat more urinary continence (P = 0.04), more stress incontinence (P = 0.048) and smaller amount of leakage (P = 0.015) in the Cohort. In conclusion, the Cohort ispopulation-based, with little selection bias, and thus is a rather unique study forinvestigating UI and LUTS in comparison with many other projects with similar purposes.</p

    Ultraviolet radiation shapes seaweed communities

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    Leukaemia incidence among workers in the shoe and boot manufacturing industry: a case-control study

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    BACKGROUND: Previous reports have indicated an excess of leukaemia in Broome County, New York, particularly in the Town of Union. Surveillance of cancer incidence data indicates that a large proportion of these cases occurred among males ages 65 and older. Shoe and boot manufacturing has been the largest single industry in this area throughout much of the past century. Occupational studies from Europe suggest a link between leukaemia and employment in the shoe and boot manufacturing industry. However, researchers have not found a positive association between leukaemia and employment in the shoe industry among workers in the United States. METHODS: A matched case-control study was conducted to investigate the association between leukaemia incidence among males 65 and older and employment in the shoe and boot manufacturing industry. Thirty-six cases of leukaemia occurring between 1981–1990; among males age 65 and older; residing in the town of Union met the study case criteria. Death certificates were obtained for each of the cases. These were matched to death certificates of 144 controls on date of death and date of birth +/- 1 year. Death certificates were then examined to determine the employer and occupation of each study subject. Conditional logistic regression was used to determine the risk of leukaemia among those working in the industry. RESULTS: The risk of both leukaemia (OR = 1.47; 95% CI 0.70, 3.09) and acute myeloid leukaemia (OR = 1.19; 95% CI 0.33, 4.28) were elevated among those employed in the shoe and boot manufacturing industry, however neither was statistically significant. CONCLUSION: The results, though suggestive of an association between leukaemia and employment in the shoe and boot manufacturing industry, were not statistically conclusive due mainly to limited study power. Several additional limitations may also have prevented the observance of more conclusive findings. Better exposure assessment, information on length of exposure and types of job held, control of confounding factors and information on chemicals used by this company would strengthen any future investigation
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