379 research outputs found

    The interfascicular matrix enables fascicle sliding and recovery in tendon, and behaves more elastically in energy storing tendons

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    While the predominant function of all tendons is to transfer force from muscle to bone and position the limbs, some tendons additionally function as energy stores, reducing the cost of locomotion. Energy storing tendons experience extremely high strains and need to be able to recoil efficiently for maximum energy storage and return. In the equine forelimb, the energy storing superficial digital flexor tendon (SDFT) has much higher failure strains than the positional common digital extensor tendon (CDET). However, we have previously shown that this is not due to differences in the properties of the SDFT and CDET fascicles (the largest tendon subunits). Instead, there is a greater capacity for interfascicular sliding in the SDFT which facilitates the greater extensions in this particular tendon (Thorpe et al., 2012). In the current study, we exposed fascicles and interfascicular matrix (IFM) from the SDFT and CDET to cyclic loading followed by a test to failure. The results show that IFM mechanical behaviour is not a result of irreversible deformation, but the IFM is able to withstand cyclic loading, and is more elastic in the SDFT than in the CDET. We also assessed the effect of ageing on IFM properties, demonstrating that the IFM is less able to resist repetitive loading as it ages, becoming stiffer with increasing age in the SDFT. These results provide further indications that the IFM is important for efficient function in energy storing tendons, and age-related alterations to the IFM may compromise function and predispose older tendons to injury

    Ctenophore population recruits entirely through larval reproduction in the central Baltic Sea

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    The comb jelly Mertensia ovum, widely distributed in Arctic regions, has recently been discovered in the northern Baltic Sea. We show that M. ovum also exists in the central Baltic but that the population consists solely of small-sized larvae (less than 1.6 mm). Despite the absence of adults, eggs were abundant. Experiments revealed that the larvae were reproductively active. Egg production and anticipated mortality rates suggest a self-sustaining population. This is the first account of a ctenophore population entirely recruiting through larval reproduction (paedogenesis). We hypothesize that early reproduction is favoured over growth to compensate for high predation pressure

    The effect of spiritual healing on in vitro tumour cell proliferation and viability – an experimental study

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    Alternative treatments such as spiritual healing and prayer are increasingly popular, especially among patients with life-threatening diseases such as cancer. According to theories of spiritual healing, this intervention is thought to influence living cells and organisms independently of the recipient's conscious awareness of the healer's intention. The aim of this study was to test the hypothesis that spiritual healing will reduce proliferation and viability of two cancer cell lines in vitro. Three controlled experiments were conducted with three different healers and randomised allocation of cells to five different doses of healing or control. Researchers conducting the assays and statistical analyses were blinded to the experimental conditions. Main outcome measures were MTT viability, 3H-thymidine incorporation and counts of an adherent human breast cancer cell line (MCF-7), and a nonadherent mouse B-lymphoid cell line (HB-94). Analyses of variance (ANOVAs) revealed no significant main or dose-related effects of spiritual healing compared to controls for either of the two cell lines or any of the assays (P-values between 0.09 and 0.96). When comparing healing and control across all three experimental days, doses, assays, and cells, 34 (51.6%) of 66 independent comparisons showed differences in the hypothesised direction (P=0.90). The average effect size across cell lines, days, assays, and doses approached zero (Cohen's d=−0.01). The results do not support previous reports of beneficial effects of spiritual healing on malignant cell growth in vitro. Reported beneficial effects of spiritual healing on the well-being of cancer patients seem more likely to be mediated by psychosocial and psychophysiological effects of the healer–patient relationship

    Role of Glomerular Proteoglycans in IgA Nephropathy

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    Mesangial matrix expansion is a prominent feature of the most common form of glomerulonephritis, IgA nephropathy (IgAN). To find molecular markers and improve the understanding of the disease, the gene and protein expression of proteoglycans were investigated in biopsies from IgAN patients and correlated to clinical and morphological data. We collected and microdissected renal biopsies from IgAN patients (n = 19) and from healthy kidney donors (n = 14). Patients were followed for an average time of 4 years and blood pressure was according to target guidelines. Distinct patterns of gene expression were seen in glomerular and tubulo-interstitial cells. Three of the proteoglycans investigated were found to be of special interest and upregulated in glomeruli: perlecan, decorin and biglycan. Perlecan gene expression negatively correlated to albumin excretion and progress of the disease. Abundant decorin protein expression was found in sclerotic glomeruli, but not in unaffected glomeruli from IgAN patients or in controls. Transforming growth factor beta (TGF-β), known to interact with perlecan, decorin and biglycan, were upregulated both on gene and protein level in the glomeruli. This study provides further insight into the molecular mechanisms involved in mesangial matrix expansion in IgAN. We conclude that perlecan is a possible prognostic marker for patients with IgAN. In addition, the up-regulation of biglycan and decorin, as well as TGF-β itself, indicate that regulation of TGF-β, and other profibrotic markers plays a role in IgAN pathology

    On the Introduction of Automatic Program Repair in Bloomberg

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    A key to the success of Automatic Program Repair techniques is how easily they can be used in an industrial setting. In this article, we describe a collaboration by a team from four UK-based universities with Bloomberg (London) in implementing automatic, high-quality fixes to its code base. We explain the motivation for adopting APR, the mechanics of the prototype tool that was built, and the practicalities of integrating APR into existing systems. IEE

    An In Vitro Model of the Glomerular Capillary Wall Using Electrospun Collagen Nanofibres in a Bioartificial Composite Basement Membrane

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    The filtering unit of the kidney, the glomerulus, contains capillaries whose walls function as a biological sieve, the glomerular filtration barrier. This comprises layers of two specialised cells, glomerular endothelial cells (GEnC) and podocytes, separated by a basement membrane. Glomerular filtration barrier function, and dysfunction in disease, remains incompletely understood, partly due to difficulties in studying the relevant cell types in vitro. We have addressed this by generation of unique conditionally immortalised human GEnC and podocytes. However, because the glomerular filtration barrier functions as a whole, it is necessary to develop three dimensional co-culture models to maximise the benefit of the availability of these cells. Here we have developed the first two tri-layer models of the glomerular capillary wall. The first is based on tissue culture inserts and provides evidence of cell-cell interaction via soluble mediators. In the second model the synthetic support of the tissue culture insert is replaced with a novel composite bioartificial membrane. This consists of a nanofibre membrane containing collagen I, electrospun directly onto a micro-photoelectroformed fine nickel supporting mesh. GEnC and podocytes grew in monolayers on either side of the insert support or the novel membrane to form a tri-layer model recapitulating the human glomerular capillary in vitro. These models will advance the study of both the physiology of normal glomerular filtration and of its disruption in glomerular disease
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