344 research outputs found

    Exposure of a tendon extracellular matrix to synovial fluid triggers endogenous and engrafted cell death: A mechanism for failed healing of intrathecal tendon injuries

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    Aim: The purpose of this study was to investigate the effect of normal synovial fluid (SF) on exposed endogenous tendon-derived cells (TDC) and engrafted mesenchymal stem cells (MSCs) within the tendon extracellular matrix. Methods: Explants from equine superficial digital flexor (extra-synovial) and deep digital flexor tendons (DDFT) from the compressed, intra-synovial and the tensile, extra-synovial regions were cultured in allogeneic or autologous SF-media. Human hamstring explants were cultured in allogeneic SF. Explant viability was assessed by staining. Proliferation of equine monolayer MSCs and TDCs in SF-media and co-culture with DDFT explants was determined by alamarblueÂź. Non-viable Native Tendon matrices (NNTs) were re-populated with MSCs or TDCs and cultured in SF-media. Immunohistochemical staining of tendon sections for the apoptotic proteins caspase-3, -8 and -9 was performed. Results: Contact with autologous or allogeneic SF resulted in rapid death of resident tenocytes in equine and human tendon. SF did not affect the viability of equine epitenon cells, or of MSCs and TDCs in monolayer or indirect explant co-culture. MSCs and TDCs, engrafted into NNTs, died when cultured in SF. Caspase-3, -8 and -9 expression was greatest in SDFT explants exposed to allogeneic SF. Conclusions: The efficacy of cells administered intra-synovially for tendon lesion repair is likely to be limited, since once incorporated into the matrix, cells become vulnerable to the adverse effects of SF. These observations could account for the poor success rate of intra-synovial tendon healing following damage to the epitenon and contact with SF, common with most soft tissue intra-synovial pathologies

    Genetic variability of Taenia saginata inferred from mitochondrial DNA sequences

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    Taenia saginata is an important tapeworm, infecting humans in many parts of the world. The present study was undertaken to identify inter- and intraspecific variation of T. saginata isolated from cattle in different parts of Iran using two mitochondrial CO1 and 12S rRNA genes. Up to 105 bovine specimens of T. saginata were collected from 20 slaughterhouses in three provinces of Iran. DNA were extracted from the metacestode Cysticercus bovis. After PCR amplification, sequencing of CO1 and 12S rRNA genes were carried out and two phylogenetic analyses of the sequence data were generated by Bayesian inference on CO1 and 12S rRNA sequences. Sequence analyses of CO1 and 12S rRNA genes showed 11 and 29 representative profiles respectively. The level of pairwise nucleotide variation between individual haplotypes of CO1 gene was 0.3–2.4 % while the overall nucleotide variation among all 11 haplotypes was 4.6 %. For 12S rRNA sequence data, level of pairwise nucleotide variation was 0.2–2.5 % and the overall nucleotide variation was determined as 5.8 % among 29 haplotypes of 12S rRNA gene. Considerable genetic diversity was found in both mitochondrial genes particularly in 12S rRNA gene. © 2015, Springer-Verlag Berlin Heidelberg

    Molecular and morphological characterization of the tapeworm Taenia hydatigena (Pallas, 1766) in sheep from Iran

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    Although Taenia hydatigena is one of the most prevalent taeniid species of livestock, very little molecular genetic information exists for this parasite. Up to 100 sheep isolates of T. hydatigena were collected from 19 abattoirs located in the provinces of Tehran, Alborz and Kerman. A calibrated microscope was used to measure the larval rostellar hook lengths. Following DNA extraction, fragments of cytochrome c oxidase 1 (CO1) and 12S rRNA genes were amplified by the polymerase chain reaction method and the amplicons were subjected to sequencing. The mean total length of large and small hooks was 203.4 Όm and 135.9 Όm, respectively. Forty CO1 and 39 12S rRNA sequence haplotypes were obtained in the study. The levels of pairwise nucleotide variation between individual haplotypes of CO1 and 12S rRNA genes were determined to be between 0.3-3.4% and 0.2-2.1%, respectively. The overall nucleotide variation among all the CO1 haplotypes was 9.7%, and for all the 12S rRNA haplotypes it was 10.1%. A significant difference was observed between rostellar hook morphometry and both CO1 and 12S rRNA sequence variability. A significantly high level of genetic variation was observed in the present study. The results showed that the 12S rRNA gene is more variable than CO1. © 2013 Cambridge University Press

    The relationship between human placental morphometry and ultrasonic measurements of utero-placental blood flow and fetal growth.

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    INTRODUCTION: Ultrasonic fetal biometry and arterial Doppler flow velocimetry are widely used to assess the risk of pregnancy complications. There is an extensive literature on the relationship between pregnancy outcomes and the size and shape of the placenta. However, ultrasonic fetal biometry and arterial Doppler flow velocimetry have not previously been studied in relation to postnatal placental morphometry in detail. METHODS: We conducted a prospective cohort study of nulliparous women in The Rosie Hospital, Cambridge (UK). We studied a group of 2120 women who had complete data on uterine and umbilical Doppler velocimetry and fetal biometry at 20, 28 and 36 weeks' gestational age, digital images of the placenta available, and delivered a liveborn infant at term. Associations were expressed as the difference in the standard deviation (SD) score of the gestational age adjusted ultrasound measurement (z-score) comparing the lowest and highest decile of the given placental morphometric measurement. RESULTS: The lowest decile of placental surface area was associated with 0.87 SD higher uterine artery Doppler mean pulsatility index (PI) at 20 weeks (95% CI: 0.68 to 1.07, P < 0.001). The lowest decile of placental weight was associated with 0.73 SD higher umbilical artery Doppler PI at 36 weeks (95% CI: 0.54 to 0.93, P < 0.001). The lowest decile of both placental weight and placental area were associated with reduced growth velocity of the fetal abdominal circumference between 20 and 36 weeks (both P < 0.001). CONCLUSION: Placental area and weight are associated with uterine and umbilical blood flow, respectively, and both are associated with fetal growth rate.This study was funded by the NIHR Cambridge Comprehensive Biomedical Research Centre (grant number A019057) and Stillbirth and Neonatal Death Society (SANDS). GE donated two ultrasound machines for use in the project.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.placenta.2015.12.00

    Candidate circulating microRNA biomarkers in dogs with chronic pancreatitis:MicroRNA BIOMARKERS CANINE PANCREATITIS

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    BACKGROUND: Pancreatitis is an important cause of disease and death in dogs. Available circulating biomarkers are not sufficiently sensitive and specific for a definitive diagnosis.HYPOTHESIS: Circulating microRNAs would be differentially expressed in dogs with chronic pancreatitis and could have potential as diagnostic biomarkers.ANIMALS: Healthy controls (n = 19) and dogs with naturally occurring pancreatitis (n = 17).METHODS: A retrospective case-control study. Dogs with pancreatitis were included if they satisfied diagnostic criteria for pancreatitis as adjudicated by 3 experts. MicroRNA was extracted from stored serum samples and sequenced. Reads were mapped to mature microRNA sequences in the canine, mouse, and human genomes. Differentially expressed microRNAs were identified and the potential mechanistic relevance explored using Qiagen Ingenuity Pathway Analysis (IPA).RESULTS: Reads mapping to 196 mature microRNA sequences were detected. Eight circulating microRNAs were significantly differentially expressed in dogs with pancreatitis (≄2-fold change and false discovery rate &lt;0.05). Four of these mapped to the canine genome (cfa-miR-221, cfa-miR-222, cfa-miR-23a, and cfa-miR-205). Three mapped to the murine genome (mmu-miR-484, mmu-miR-6240, mmu-miR-101a-3p) and 1 to the human genome (hsa-miR-1290). Expression in dogs with pancreatitis was higher for 7 microRNAs and lower for mmu-miR-101a-3p. Qiagen IPA demonstrated a number of the differently expressed microRNAs are involved in a common pancreatic inflammatory pathway.CONCLUSIONS: The significantly differentially expressed microRNAs represent promising candidates for further validation as diagnostic biomarkers for canine pancreatitis.</p

    Noise facilitation in associative memories of exponential capacity

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    Recent advances in associative memory design through structured pattern sets and graph-based inference al- gorithms have allowed reliable learning and recall of an exponential number of patterns. Although these designs correct external errors in recall, they assume neurons that compute noiselessly, in contrast to the highly variable neurons in brain regions thought to operate associatively such as hippocampus and olfactory cortex. Here we consider associative memories with noisy internal computations and analytically characterize performance. As long as the internal noise level is below a specified threshold, the error probability in the recall phase can be made exceedingly small. More surprisingly, we show that internal noise actually improves the performance of the recall phase while the pattern retrieval capacity remains intact, i.e., the number of stored patterns does not reduce with noise (up to a threshold). Computational experiments lend additional support to our theoretical analysis. This work suggests a functional benefit to noisy neurons in biological neuronal networks

    Numerical Study on the Effects of Fuel Injection Characteristics on the Performance of a Lean Burn SG-GDI Engine towards High Efficiency and Emissions Reduction

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    The effects of spark and injection characteristics as well as split injection on the performance and emissions of a spray-guided gasoline direct injection (SG-GDI) engine operating close to stoichiometric conditions are assessed. To accomplish this, a 6-holes injector is simulated and the results are validated against available experimental data for spray penetration length. In addition, an open-cycle multi-dimensional model is developed for a port fuel injection (PFI) engine and the model outcomes are verified against in-cylinder pressure profile and normalized heat release rate. The GDI engine model is yielded under the light of embedment of the above-mentioned models. The model is then employed for investigation of the effects of injector angle, injection pressure, start of first and second injections and two-stage fuel injection with different fuel mass ratios at first and second injections, i.e., split injection, on mixture formation, combustion and engine emissions. The results show the pivotal role of the injector angle on formation of the mixture and output power. On the other hand, it is indicated that while practicing the split injection strategy, the flammability of the relatively stratified lean mixture with fuel to air equivalence ratio of 1.15 around the spark plug, surpasses that of stratified mixture

    18F-NaF and 18F-FDG as molecular probes in the evaluation of atherosclerosis

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    The early detection of atherosclerotic disease is vital to the effective prevention and management of life-threatening cardiovascular events such as myocardial infarctions and cerebrovascular accidents. Given the potential for positron emission tomography (PET) to visualize atherosclerosis earlier in the disease process than anatomic imaging modalities such as computed tomography (CT), this application of PET imaging has been the focus of intense scientific inquiry. Although 18F-FDG has historically been the most widely studied PET radiotracer in this domain, there is a growing body of evidence that 18F-NaF holds significant diagnostic and prognostic value as well. In this article, we review the existing literature on the application of 18F-FDG and 18F-NaF as PET probes in atherosclerosis and present the findings of original animal and human studies that have examined how well 18F-NaF uptake correlates with vascular calcification and cardiovascular risk

    Association of serum and fecal microRNA profiles in cats with gastrointestinal cancer and chronic inflammatory enteropathy

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    Background: Differentiation of gastrointestinal cancer (GIC) from chronic inflammatory enteropathies (CIE) in cats can be challenging and often requires extensive diagnostic testing. MicroRNAs (miRNAs) have promise as non‐invasive biomarkers in serum and feces for diagnosis of GIC. Hypothesis/Objectives: Cats with GIC will have serum and fecal miRNA profiles that differ significantly from healthy cats and cats with CIE. Identify serum and fecal miRNAs with diagnostic potential for differentiation between cats with GIC and CIE as compared to healthy cats. Animals: Ten healthy cats, 9 cats with CIE, and 10 cats with GIC; all client‐owned. Methods: Cats were recruited for an international multicenter observational prospective case‐control study. Serum and feces were screened using small RNA sequencing for miRNAs that differed in abundance between cats with GIC and CIE, and healthy cats. Diagnostic biomarker potential of relevant miRNAs from small RNA sequencing and the literature was confirmed using reverse transcription quantitative real‐time PCR (RT‐qPCR). Results: Serum miR‐223‐3p was found to distinguish between cats with GIC and CIE with an area under the curve (AUC) of 0.9 (95% confidence interval [CI], 0.760‐1.0), sensitivity of 90% (95% CI, 59.6‐99.5%), and specificity of 77.8% (95% CI, 45.3‐96.1%). Serum miR‐223‐3p likewise showed promise in differentiating a subgroup of cats with small cell lymphoma (SCL) from those with CIE. No fecal miRNAs could distinguish between cats with GIC and CIE. Conclusion and Clinical Importance: Serum miR‐223‐3p potentially may serve as a noninvasive diagnostic biomarker of GIC in cats, in addition to providing a much needed tool for the differentiation of CIE and SCL
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