430 research outputs found

    Intravesicle Isothermal DNA Replication

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    <p>Abstract</p> <p>Background</p> <p>Bacterial and viral DNA replication was previously reconstituted <it>in vitro </it>from component parts <abbrgrp><abbr bid="B1">1</abbr><abbr bid="B2">2</abbr><abbr bid="B3">3</abbr><abbr bid="B4">4</abbr></abbrgrp>. Significant advances in building minimal cell-like structures also have been made recently <abbrgrp><abbr bid="B5">5</abbr><abbr bid="B6">6</abbr><abbr bid="B7">7</abbr></abbrgrp>. Combining the two approaches would further attempts to build a minimal cell-like structure capable of undergoing evolution by combining membrane encapsulation and genome replication. Towards this end, we attempted to use purified genomic replication protein components from thermophilic bacterial sources to copy strands of DNA isothermally within lipid vesicles.</p> <p>Findings</p> <p>Bacterial replication components (such as helicases and DNA polymerases) are compatible with methods for the generation of lipid vesicles. Encapsulation inside phospholipid vesicles does not inhibit the activity of bacterial DNA genome replication machinery. Further the described system is efficient at isothermally amplifying short segments of DNA within phospholipid vesicles.</p> <p>Conclusions</p> <p>Herein we show that bacterial isothermal DNA replication machinery is functional inside of phospholipid vesicles, suggesting that replicating cellular mimics can be built from purified bacterial components.</p

    A conceptual cellular interaction model of left ventricular remodelling post-MI: dynamic network with exit-entry competition strategy

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    Abstract Background Progressive remodelling of the left ventricle (LV) following myocardial infarction (MI) is an outcome of spatial-temporal cellular interactions among different cell types that leads to heart failure for a significant number of patients. Cellular populations demonstrate temporal profiles of flux post-MI. However, little is known about the relationship between cell populations and the interaction strength among cells post-MI. The objective of this study was to establish a conceptual cellular interaction model based on a recently established graph network to describe the interaction between two types of cells. Results We performed stability analysis to investigate the effects of the interaction strengths, the initial status, and the number of links between cells on the cellular population in the dynamic network. Our analysis generated a set of conditions on interaction strength, structure of the network, and initial status of the network to predict the evolutionary profiles of the network. Computer simulations of our conceptual model verified our analysis. Conclusions Our study introduces a dynamic network to model cellular interactions between two different cell types which can be used to model the cellular population changes post-MI. The results on stability analysis can be used as a tool to predict the responses of particular cell populations

    Gangs and guilt: Towards a new theory of horror film

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    The most basic and unanimous statement made in scholarship on horror films is that horror films are ‘about’ fear: the primary purpose of horror films is to scare viewers. Based on horror films from the 1970s until the present in which child gangs play a significant part, this essay advances a new theory of horror film, namely that horror films primarily seek to elicit not fear but guilt. The analysis focuses on four topics: themes, camera angles, horror’s cinematic casting of ‘abnormality,’ and the rift, unique to the horror genre, between audience ‘alignment’ and ‘allegiance.

    Children’s perceptions of dissimilarity in parenting styles are associated with internalizing and externalizing behavior

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    The purpose of this study was to examine the relationship between children’s perception of dissimilarity in parenting styles, and internalizing and externalizing problems in children. Children from the general population (n = 658) reported on the level of emotional warmth, rejection, and overprotection of both parents by filling out the child version of the Egna Minnen Beträffande Uppfostran (EMBU-C) and mothers completed the child behavior checklist (CBCL). Intraclass correlations were computed as measures of dissimilarity between parenting styles of mothers and fathers. Children’s perceived dissimilarity in parental emotional warmth is associated with internalizing and externalizing problems (β = 0.092, p < 0.05; β = 0.091, p < 0.05). Perceived dissimilarity between parents’ overprotection is associated with externalizing problems (β = 0.097, p < 0.05). Perceived dissimilarity between parenting styles is associated with externalizing and internalizing problems, over and above the effects of the level of the parenting styles. The results highlight the negative consequences of perceived dissimilarity between parents. To conclude, children have more internalizing and externalizing problems when they perceive their parents as more dissimilar in parenting styles

    Instrumented fusion of thoracolumbar fracture with type I mineralized collagen matrix combined with autogenous bone marrow as a bone graft substitute: a four-case report

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    In order to avoid the morbidity from autogenous bone harvesting, bone graft substitutes are being used more frequently in spinal surgery. There is indirect radiological evidence that bone graft substitutes are efficacious in humans. The purpose of this four-case study was to visually, manually, and histologically assess the quality of a fusion mass produced by a collagen hydroxyapatite scaffold impregnated with autologous bone marrow aspirate for posterolateral fusion. Four patients sustained an acute thoracolumbar fracture and were treated by short posterior segment fusion using the AO fixateur interne. Autologous bone marrow (iliac crest) impregnated hydroxyapatite-collagen scaffold was laid on the decorticated posterior elements. Routine implant removal was performed after a mean of 15.3 months (12–20). During this second surgery, fusion mass was assessed visually and manually. A bone biopsy was sent for histological analysis of all four cases. Fusion was confirmed in all four patients intraoperatively and sagittal stress testing confirmed mechanical adequacy of the fusion mass. Three out of the four (cases 2–4) had their implants removed between 12 and 15 months after the index surgery. All their histological cuts showed evidence of newly formed bone and presence of active membranous and/or enchondral ossification foci. The last patient (case 1) underwent implant removal at 20 months and his histological cuts showed mature bone, but no active ossification foci. This four-case report suggests that the fusion mass produced by a mineralized collagen matrix graft soaked in aspirated bone marrow is histologically and mechanically adequate in a thoracolumbar fracture model. A larger patient series and/or randomized controlled studies are warranted to confirm these initial results

    Epigenetic regulation of S100 protein expression

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    S100 proteins are small, calcium-binding proteins whose genes are localized in a cluster on human chromosome 1. Through their ability to interact with various protein partners in a calcium-dependent manner, the S100 proteins exert their influence on many vital cellular processes such as cell cycle, cytoskeleton activity and cell motility, differentiation, etc. The characteristic feature of S100 proteins is their cell-specific expression, which is frequently up- or downregulated in various pathological states, including cancer. Changes in S100 protein expression are usually characteristic for a given type of cancer and are therefore often considered as markers of a malignant state. Recent results indicate that changes in S100 protein expression may depend on the extent of DNA methylation in the S100 gene regulatory regions. The range of epigenetic changes occurring within the S100 gene cluster has not been defined. This article reviews published data on the involvement of epigenetic factors in the control of S100 protein expression in development and cancer

    Comparative Assessment of Copper, Iron, and Zinc Contents in Selected Indian (Assam) and South African (Thohoyandou) Tea (Camellia sinensis L.) Samples and Their Infusion: A Quest for Health Risks to Consumer

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    The current study aims to assess the infusion pattern of three important micronutrients namely copper (Cu), iron (Fe), and zinc (Zn) contents from black tea samples produced in Assam (India) and Thohoyandou (South Africa). Average daily intakes and hazardous quotient were reported for these micronutrients. Total content for Cu, Fe, and Zn varied from 2.25 to 48.82 mg kg−1, 14.75 to 148.18 mg kg−1, and 28.48 to 106.68 mg kg−1, respectively. The average contents of each of the three micronutrients were higher in tea leaves samples collected from South Africa than those from India while the contents in tea infusions in Indian samples were higher than in South African tea samples. Results of this study revealed that the consumption of 600 mL tea infusion produced from 24 g of made tea per day may be beneficial to human in terms of these micronutrients content. Application of nonparametric tests revealed that most of the data sets do not satisfy the normality assumptions. Hence, the use of both parametric and nonparametric statistical analysis that subsequently revealed significant differences in elemental contents among Indian and South African tea

    Molecular imaging of angiogenesis with SPECT

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    Single-photon emission computed tomography (SPECT) and position emission tomography (PET) are the two main imaging modalities in nuclear medicine. SPECT imaging is more widely available than PET imaging and the radionuclides used for SPECT are easier to prepare and usually have a longer half-life than those used for PET. In addition, SPECT is a less expensive technique than PET. Commonly used gamma emitters are: 99mTc (Emax 141 keV, T1/2 6.02 h), 123I (Emax 529 keV, T1/2 13.0 h) and 111In (Emax 245 keV, T1/2 67.2 h). Compared to clinical SPECT, PET has a higher spatial resolution and the possibility to more accurately estimate the in vivo concentration of a tracer. In preclinical imaging, the situation is quite different. The resolution of microSPECT cameras (<0.5 mm) is higher than that of microPET cameras (>1.5 mm). In this report, studies on new radiolabelled tracers for SPECT imaging of angiogenesis in tumours are reviewed
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