367 research outputs found

    Oral manifestations of inflammatory bowel disease

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    Inflammatory bowel diseases (IBD), including Crohn\u2019s disease and ulcerative colitis, have important extraintestinal manifestations, notably in the oral cavity. These oral manifestations can constitute important clinical clues in the diagnosis and management of IBD, and include changes at the immune and bacterial levels. Aphthous ulcers, pyostomatitis vegetans, cobblestoning and gingivitis are important oral findings frequently observed in IBD patients. Their presentations vary considerably and might be well diagnosed and distinguished from other oral lesions. Infections, drug side effects, deficiencies in some nutrients and many other diseases involved with oral manifestations should also be taken into account. This article discusses the most recent findings on the oral manifestations of IBD with a focus on bacterial modulations and immune changes. It also includes an overview on options for management of the oral lesions of IBD

    Verification and Validation of Computational Models for Ultrasonic Testing

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    The Pacific Northwest National Laboratory (PNNL) is conducting confirmatory research for the U.S. Nuclear Regulatory Commission (NRC) for the verification and validation of computational models used in ultrasonic testing (UT). This paper discusses some of the findings obtained from simple geometrical reflectors in isotropic, fine-grained, homogeneous materials with conventional ultrasonic transducers. A total of 348 ultrasonic raster scans were acquired using pulse-echo conventional probes with different diameters, beam angles, wave modalities, and frequencies. The raster scans contained reflections from machined notches (flaws) of different sizes and orientations. High frequency pencil beam models, and flaw scattering models employing the Kirchhoff and geometric theory of diffraction approximations, were then used to simulate the corresponding experimental measurements. CIVA, a semi-analytical nondestructive evaluation (NDE) simulation platform developed by the French Commissariat à l’Energie Atomique (CEA), was used to run simulations based on the approximation models. The experimental measurements were compared to their modeled counterparts using quantitative metrics obtained from the C-scans, B-scans and A-scans. To address uncertainties in the input parameters to the computational model, parametric studies and sensitivity analyses were conducted on all the relevant inputs. Sources of discrepancies between the experiment and simulated results are discussed in terms of numerical model errors and uncertainties in the experiments and model input parameters

    Factors associated with Autism Spectrum Disorder: a case-control study in the Lebanese population

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    Background: Genetic factors represent the major etiological contributor in Autism Spectrum Disorders (ASD) but several studies also support the involvement of environmental factors. This last hypothesis is reinforced by the evident increase in the prevalence of this disorder in the last decades. Thus, in our study, we aimed to identify the correlation between factors related to sociodemographic elements, to child and mother’s health and ASD in order to dress a best detailed profile of the patients. Methods: We conducted a case-control study including 64 Lebanese patients with ASD and 67 matched controls recruited from all the Lebanese districts. Our data has been analyzed by SPSS 23.0 and the statistical tests carried out were the Independent Sample t-test and the Chi-Square test. In addition, a multivariate logistic regression analysis has been carried out using variables that showed a p<0.05 in the bivariate analysis. Results: Our findings suggest that consanguinity (OR=4; 95% CI [1.3-12.04]), familial history of ASD (6.7 [1.1- 39.3]), stress during pregnancy (3.6 [1.5 8.2]) and fetal prematurity (6.3 [1.2-33.01]) were significantly associated with increased odds of ASD. However, our results have shown no association between siblings suffering from diseases such as mental retardation, child’s infections and ASD. Conclusion: This pilot study carried out in all the regions of Lebanon allowed us to shed the light on factors associated with ASD which might be preventable

    Three-dimensional hypoxic culture of human mesenchymal stem cells encapsulated in a photocurable, biodegradable polymer hydrogel: a potential injectable cellular product for nucleus pulposus regeneration

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    Nucleus pulposus (NP) tissue damage can induce detrimental mechanical stresses and strains on the intervertebral disc, leading to disc degeneration. This study demonstrates the potential of a novel, photo-curable, injectable, synthetic polymer hydrogel (pHEMA-co-APMA grafted with polyamidoamine (PAA)) to encapsulate and differentiate human mesenchymal stem cells (hMSC) towards a NP phenotype under hypoxic conditions which could be used to restore NP tissue function and mechanical properties. Encapsulated hMSC cultured in media (hMSC and chondrogenic) displayed good cell viability up to day 14. The genotoxicity effects of ultraviolet (UV) on hMSC activity confirmed the acceptability of 2.5min of UV light exposure to cells. Cytotoxicity investigations revealed that hMSC cultured in media containing p(HEMA-co-APMA) grafted with PAA degradation product (10% and 20%v/v concentration) for 14days significantly decreased the initial hMSC adhesion ability and proliferation rate from 24h to day 14. Successful differentiation of encapsulated hMSC within hydrogels towards chondrogenesis was observed with elevated expression levels of aggrecan and collagen II when cultured in chondrogenic media under hypoxic conditions, in comparison with culture in hMSC media for 14days. Characterization of the mechanical properties revealed a significant decrease in stiffness and modulus values of cellular hydrogels in comparison with acellular hydrogels at both day 7 and day 14. These results demonstrate the potential use of an in vivo photo-curable injectable, synthetic hydrogel with encapsulated hMSC for application in the repair and regeneration of NP tissue

    Three-dimensional hypoxic culture of human mesenchymal stem cells encapsulated in a photocurable, biodegradable polymer hydrogel: a potential injectable cellular product for nucleus pulposus regeneration

    Get PDF
    Nucleus pulposus (NP) tissue damage can induce detrimental mechanical stresses and strains on the intervertebral disc, leading to disc degeneration. This study demonstrates the potential of a novel, photo-curable, injectable, synthetic polymer hydrogel (pHEMA-co-APMA grafted with polyamidoamine (PAA)) to encapsulate and differentiate human mesenchymal stem cells (hMSC) towards a NP phenotype under hypoxic conditions which could be used to restore NP tissue function and mechanical properties. Encapsulated hMSC cultured in media (hMSC and chondrogenic) displayed good cell viability up to day 14. The genotoxicity effects of ultraviolet (UV) on hMSC activity confirmed the acceptability of 2.5min of UV light exposure to cells. Cytotoxicity investigations revealed that hMSC cultured in media containing p(HEMA-co-APMA) grafted with PAA degradation product (10% and 20%v/v concentration) for 14days significantly decreased the initial hMSC adhesion ability and proliferation rate from 24h to day 14. Successful differentiation of encapsulated hMSC within hydrogels towards chondrogenesis was observed with elevated expression levels of aggrecan and collagen II when cultured in chondrogenic media under hypoxic conditions, in comparison with culture in hMSC media for 14days. Characterization of the mechanical properties revealed a significant decrease in stiffness and modulus values of cellular hydrogels in comparison with acellular hydrogels at both day 7 and day 14. These results demonstrate the potential use of an in vivo photo-curable injectable, synthetic hydrogel with encapsulated hMSC for application in the repair and regeneration of NP tissue

    Arrhythmogenic gene remodelling in elderly patients with type 2 diabetes with aortic stenosis and normal left ventricular ejection fraction

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    New Findings What is the central question of this study? Type 2 diabetes is associated with a higher rate of ventricular arrhythmias compared with the non‐diabetic population, but the associated myocardial gene expression changes are unknown; furthermore, it is also unknown whether any changes are attributable to chronic hyperglycaemia or are a consequence of structural changes. What is the main finding and its importance? We found downregulation of left ventricular ERG gene expression and increased NCX1 gene expression in humans with type 2 diabetes compared with control patients with comparable left ventricular hypertrophy and possible myocardial fibrosis. This was associated with QT interval prolongation. Diabetes and associated chronic hyperglycaemia may therefore promote ventricular arrhythmogenesis independently of structural changes. Type 2 diabetes is associated with a higher rate of ventricular arrhythmias, and this is hypothesized to be independent of coronary artery disease or hypertension. To investigate further, we compared changes in left ventricular myocardial gene expression in type 2 diabetes patients with patients in a control group with left ventricular hypertrophy. Nine control patients and seven patients with type 2 diabetes with aortic stenosis undergoing aortic valve replacement had standard ECGs, signal‐averaged ECGs and echocardiograms before surgery. During surgery, a left ventricular biopsy was taken, and mRNA expressions for genes relevant to the cardiac action potential were estimated by RT‐PCR. Mathematical modelling of the action potential and calcium transient was undertaken using the O'Hara–Rudy model using scaled changes in gene expression. Echocardiography revealed similar values for left ventricular size, filling pressures and ejection fraction between groups. No difference was seen in positive signal‐averaged ECGs between groups, but the standard ECG demonstrated a prolonged QT interval in the diabetes group. Gene expression of KCNH2 and KCNJ3 were lower in the diabetes group, whereas KCNJ2 , KCNJ5 and SLC8A1 expression were higher. Modelling suggested that these changes would lead to prolongation of the action potential duration with generation of early after‐depolarizations secondary to a reduction in density of the rapid delayed rectifier K+ current and increased Na+–Ca2+ exchange current. These data suggest that diabetes leads to pro‐arrythmogenic changes in myocardial gene expression independently of left ventricular hypertrophy or fibrosis in an elderly population

    Understanding Russia's return to the Middle East

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    Over recent years, there has been a significant resurgence of Russian power and influence in the Middle East, which has been evident in the diplomatic and military intervention into Syria. This article identifies the principal factors behind Russia’s return to the region. First, there are domestic political influences with the coincidence of the uprisings in the Middle East, the so-called ‘Arab Spring,’ with large-scale domestic opposition protests within Russia during the elections in 2011–2012. Second, there is the role of ideas, most notably the growing anti-Westernism in Putin’s third presidential term, along with Russia’s own struggle against Islamist terrorism. These ideational factors contributed to Russia’s resolve to support the Assad government against both Western intervention and its domestic Islamist opposition. Third, Russia has benefited from a pragmatic and flexible approach in its engagement with the region. Moscow seeks to ensure that it is a critical actor for all the various states and political movements in the Middle East

    COLORECTAL CANCER: AN UPDATE ON THE EFFECTS OF LYCOPENE ON TUMOR PROGRESSION AND CELL PROLIFERATION

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    Colorectal cancer (CRC) is one of the most common cancers worldwide. Various factors, including oxidative stress, where excessive productions of reactive oxygen species (ROS) and reactive nitrogen species (RNS) occur, contribute to its pathogenesis. Numerous studies have investigated the effect of antioxidant substances derived from food such fruits and vegetables; however, data on Lycopene are still rare. Stidies on HT-29 colorectal cancer cells and on animal models have shown that Lycopene has effects on cell proliferation and on the progression of the CRC by interacting with variuos cellular signaling pathways. this analysis of the literature focused on the antioxidant effect of Lycopene, a substance that is found in the tomato
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