59 research outputs found

    The Potential of N-Rich Plasma-Polymerized Ethylene (PPE:N) Films for Regulating the Phenotype of the Nucleus Pulposus

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    We recently developed a nitrogen-rich plasma-polymerized biomaterial, designated “PPE:N” (N-doped plasma-polymerized ethylene) that is capable of suppressing cellular hypertrophy while promoting type I collagen and aggrecan expression in mesenchymal stem cells from osteoarthritis patients. We then hypothesized that these surfaces would form an ideal substrate on which the nucleus pulposus (NP) phenotype would be maintained. Recent evidence using microarrays showed that in young rats, the relative mRNA levels of glypican-3 (GPC3) and pleiotrophin binding factor (PTN) were significantly higher in nucleus pulposus (NP) compared to annulus fibrosus (AF) and articular cartilage. Furthermore, vimentin (VIM) mRNA levels were higher in NP versus articular cartilage. In contrast, the levels of expression of cartilage oligomeric matrix protein (COMP) and matrix gla protein precursor (MGP) were lower in NP compared to articular cartilage. The objective of this study was to compare the expression profiles of these genes in NP cells from fetal bovine lumbar discs when cultured on either commercial polystyrene (PS) tissue culture dishes or on PPE:N with time. We found that the expression of these genes varies with the concentration of N ([N]). More specifically, the expression of several genes of NP was sensitive to [N], with a decrease of GPC3, VIM, PTN, and MGP in function of decreasing [N]. The expression of aggrecan, collagen type I, and collagen type II was also studied: no significant differences were observed in the cells on different surfaces with different culture time. The results support the concept that PPE:N may be a suitable scaffold for the culture of NP cells. Further studies are however necessary to better understand their effects on cellular phenotypes

    Cooperation of Mtmr8 with PI3K Regulates Actin Filament Modeling and Muscle Development in Zebrafish

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    It has been shown that mutations in at least four myotubularin family genes (MTM1, MTMR1, 2 and 13) are causative for human neuromuscular disorders. However, the pathway and regulative mechanism remain unknown.Here, we reported a new role for Mtmr8 in neuromuscular development of zebrafish. Firstly, we cloned and characterized zebrafish Mtmr8, and revealed the expression pattern predominantly in the eye field and somites during early somitogenesis. Using morpholino knockdown, then, we observed that loss-of-function of Mtmr8 led to defects in somitogenesis. Subsequently, the possible underlying mechanism and signal pathway were examined. We first checked the Akt phosphorylation, and observed an increase of Akt phosphorylation in the morphant embryos. Furthermore, we studied the PH/G domain function within Mtmr8. Although the PH/G domain deletion by itself did not result in embryonic defect, addition of PI3K inhibitor LY294002 did give a defective phenotype in the PH/G deletion morphants, indicating that the PH/G domain was essential for Mtmr8's function. Moreover, we investigated the cooperation of Mtmr8 with PI3K in actin filament modeling and muscle development, and found that both Mtmr8-MO1 and Mtmr8-MO2+LY294002 led to the disorganization of the actin cytoskeleton. In addition, we revealed a possible participation of Mtmr8 in the Hedgehog pathway, and cell transplantation experiments showed that Mtmr8 worked in a non-cell autonomous manner in actin modeling.The above data indicate that a conserved functional cooperation of Mtmr8 with PI3K regulates actin filament modeling and muscle development in zebrafish, and reveal a possible participation of Mtmr8 in the Hedgehog pathway. Therefore, this work provides a new clue to study the physiological function of MTM family members

    The impact of co-infections on fish: a review

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    International audienceAbstractCo-infections are very common in nature and occur when hosts are infected by two or more different pathogens either by simultaneous or secondary infections so that two or more infectious agents are active together in the same host. Co-infections have a fundamental effect and can alter the course and the severity of different fish diseases. However, co-infection effect has still received limited scrutiny in aquatic animals like fish and available data on this subject is still scarce. The susceptibility of fish to different pathogens could be changed during mixed infections causing the appearance of sudden fish outbreaks. In this review, we focus on the synergistic and antagonistic interactions occurring during co-infections by homologous or heterologous pathogens. We present a concise summary about the present knowledge regarding co-infections in fish. More research is needed to better understand the immune response of fish during mixed infections as these could have an important impact on the development of new strategies for disease control programs and vaccination in fish

    Roles of spatial scale and rarity on the relationship between butterfly species richness and human density in South Africa

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    Wildlife and humans tend to prefer the same productive environments, yet high human densities often lead to reduced biodiversity. Species richness is often positively correlated with human population density at broad scales, but this correlation could also be caused by unequal sampling effort leading to higher species tallies in areas of dense human activity. We examined the relationships between butterfly species richness and human population density at five spatial resolutions ranging from 2′ to 60′ across South Africa. We used atlas-type data and spatial interpolation techniques aimed at reducing the effect of unequal spatial sampling. Our results confirm the general positive correlation between total species richness and human population density. Contrary to our expectations, the strength of this positive correlation did not weaken at finer spatial resolutions. The patterns observed using total species richness were driven mostly by common species. The richness of threatened and restricted range species was not correlated to human population density. None of the correlations we examined were particularly strong, with much unexplained variance remaining, suggesting that the overlap between butterflies and humans is not strong compared to other factors not accounted for in our analyses. Special consideration needs to be made regarding conservation goals and variables used when investigating the overlap between species and humans for biodiversity conservation

    Improving PBL in Empowering Meta cognitive Skill of Students

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    Abstract Objective: Problem-Based Learning (PBL) is a potential constructivist learning strategy that empowers students’ Meta cognitive skill. PBL focuses on problem, involves thinking activity to solve problems, and correlates to cognitive function of students. Methods: The implementation of PBL reveals various benefits, but there are also some weaknesses in this learning strategy. Thus, it is necessary to implement a certain learning strategy that can cover the PBL weaknesses, such as Reading, Questioning, and Answering (RQA) learning strategy. RQA is a new learning strategy developed based on a fact that almost all students do not read the next lecture materials, causing failure of learning strategy planned and finally the students’ comprehension becomes low. RQA is also potential to empower students’ Meta cognitive skill. Findings: The integration of RQA and PBL learning strategy is called PBL-RQA learning strategy. This study was a quasi-experimental study designed to compare the effect of PBL, RQA, and PBL-RQA learning strategies on the students’ Meta cognitive skill of Faculty of Mathematics and Science, State University of Makassar. Application: The results of the study showed that the potency of PBL learning strategy in empowering the students’ Meta cognitive skill has been increased by integrating it to RQA learning strategy. The meta cognitive skill mean score of the students taught by PBL-RQA learning strategy was 21% higher than that of the students taught by PBL and 26.9% higher than that of the students taught by RQA learning strategy. Keywords: Answering, Meta Cognitive Skill, Problem-Based Learning, Questioning, Reading, PBL-RQ

    Usual dietary anthocyanin intake, sources and their association with blood pressure in a representative sample of Australian adults

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    Background: Anthocyanins represent an important subgroup of non-nutritive components of food as evidence continues to build related to their beneficial bioactive effects. Using a recently developed Australian anthocyanin database, the present study aimed to estimate the intake of both total anthocyanins and their subclasses, identify food sources of anthocyanins, and determine associations between anthocyanin intake and measured blood pressure (BP). Methods: The present study comprised was a secondary analysis of the 2011-12 National Nutrition and Physical Activity component of the Australian Health Survey. Anthocyanin intake was estimated using an Australian anthocyanin database. Usual anthocyanin intake, as estimated from 24-h diet recall data, was computed using multiple source methods, whereas food sources were determined by calculating contribution of food groups to total anthocyanin intake. Regression analysis, adjusted for covariates (age, gender, body mass index, high BP) diagnosis, smoking status and physical activity) assessed the relationship between anthocyanin intake and BP in adults aged ≥50 years. Results: Mean anthocyanin intake was 24.17 ± 0.32 mg day −1 . Across age groups, berries were the top sources: blackberry (5-65%), cherry (2-24%), blueberry (2-13%) and raspberry (3-12%). There was a significant inverse association between anthocyanin intake and systolic BP (β = −0.04, F = 16.8, d.f. = 6, r2 = 0.05, P \u3c 0.01) and diastolic BP (β = 0.01, F = 5.35, d.f. = 6, R2 = 0.013, P \u3c 0.01), in models that adjusted for covariates. Conclusions: In comparison with the world composite database, anthocyanin intake in the Australian population was above average [mean (SD): 24.17 (0.32) mg day−1 versus 18.05 (21.14) mg day−1]. Berries comprised up the primary source of anthocyanins. Anthocyanin intake in older adults aged aged ≥50 years was inversely associated with BP
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