249 research outputs found

    Atrial natriuretic peptide effects on intracellular pH changes and ROS production in HEPG2 cells: Role of p38 MAPK and phospholipase D

    Get PDF
    Aims: The present study was performed to evaluate Atrial Natriuretic Peptide ( ANP) effects on intracellular pH, phospholipase D and ROS production and the possible relationship among them in HepG2 cells. Cancer extracellular microenvironment is more acidic than normal tissues and the activation of NHE- 1, the only system able to regulate pHi homeostasis in this condition, can represent an important event in cell proliferation and malignant transformation. Methods: The ANP effects on pHi were evaluated by fluorescence spectrometry. The effects on p38 MAPK and ROS production were evaluated by immunoblots and analysis of DCF- DA fluorescence, respectively. RT- PCR analysis and Western blotting were used to determine the ANP effect on mRNA NHE- 1 expression and protein levels. PLD- catalyzed conversion of phosphatidylcholine to phosphatydilethanol ( PetOH), in the presence of ethanol, was monitored by thin layer chromatography. Results: A significant pHi decrease was observed in ANP- treated HepG2 cells and this effect was paralleled by the enhancement of PLD activity and ROS production. The ANP effect on pHi was coupled to an increased p38 MAPK phosphorylation and a down- regulation of mRNA NHE- 1 expression and protein levels. Moreover, the relationship between PLD and ROS production was demonstrated by calphostin- c, a potent inhibitor of PLD. At the same time, all assessed ANP- effects were mediated by NPR- C receptors. Conclusion: Our results indicate that ANP recruits a signal pathway associated with p38 MAPK, NHE- 1 and PLD responsible for ROS production, suggesting a possible role for ANP as novel modulator of ROS generation in HepG2 cells. Copyright (C) 2005 S. Karger AG, Basel

    NOT JUST A WOMEN’S ISSUE: HOW MALE UNDERGRADUATE STUDENTS UNDERSTAND THEIR DEVELOPMENT AS SOCIAL JUSTICE ALLIES FOR PREVENTING MEN’S VIOLENCE AGAINST WOMEN

    Get PDF
    Men’s violence against women includes acquaintance rape, intimate partner violence, sexual assault, and partner stalking and occurs at particularly high rates on college campuses (Fisher, Cullen, & Turner, 2000). Although men are increasingly becoming involved in efforts to prevent these forms of violence, little is known about their motivation and the processes that lead to their involvement. The purpose of this project was to examine how undergraduate male students become social justice allies involved in preventing men’s violence against women. The theoretical frameworks of this study included transformative learning theory (Mezirow, 1997, 2000) and feminist theory (Worell & Remer, 2003). Data were generated from six male social justice ally exemplars nominated for their sustained involvement in prevention work. Eligible and interested participants completed two individual interviews, demographic forms, Social Locations Worksheets (Worell & Remer, 2003), and male social justice ally development timelines. The qualitative data were analyzed using constructivist grounded theory (Charmaz, 2006) by the author and three peer debriefers. Findings provide an initial framework for conceptualizing male social justice ally development, including predisposing factors and shifts in perspective that were critical to their antiviolence work and factors that sustained their involvement. Participants also described integrating their social justice ally work into their identity and connecting with other forms of social activism. These themes provide a framework for understanding how men become invested in preventing men’s violence against women as undergraduate students and implications for ways to engage more men in these efforts

    Human cardiac progenitor cell grafts as unrestricted source of supernumerary cardiac cells in healthy murine hearts

    Get PDF
    Human heart harbors a population of resident progenitor cells that can be isolated by stem cell antigen-1 antibody and expanded in culture. These cells can differentiate into cardiomyocytes in vitro and contribute to cardiac regeneration in vivo. However, when directly injected as single cell suspension, less than 1%-5% survive and differentiate. Among the major causes of this failure are the distressing protocols used to culture in vitro and implant progenitor cells into damaged hearts. Human cardiac progenitors obtained from the auricles of patients were cultured as scaffoldless engineered tissues fabricated using temperature-responsive surfaces. In the engineered tissue, progenitor cells established proper three-dimensional intercellular relationships and were embedded in self-produced extracellular matrix preserving their phenotype and multipotency in the absence of significant apoptosis. After engineered tissues were leant on visceral pericardium, a number of cells migrated into the murine myocardium and in the vascular walls, where they integrated in the respective textures. The study demonstrates the suitability of such an approach to deliver stem cells to the myocardium. Interestingly, the successful delivery of cells in murine healthy hearts suggests that myocardium displays a continued cell cupidity that is strictly regulated by the limited release of progenitor cells by the adopted source. When an unregulated cell source is added to the system, cells are delivered to the myocardium. The exploitation of this novel concept may pave the way to the setup of new protocols in cardiac cell therapy. STEM CELLS 2011;29:2051-206

    Multiscale three-dimensional scaffolds for soft tissue engineering via multimodal electrospinning

    Get PDF
    A novel (scalable) electrospinning process was developed to fabricate bio-inspired multiscale three-dimensional scaffolds endowed with a controlled multimodal distribution of fiber diameters and geared towards soft tissue engineering. The resulting materials finely mingle nano- and microscale fibers together, rather than simply juxtaposing them, as is commonly found in the literature. A detailed proof of concept study was conducted on a simpler bimodal poly(ε-caprolactone) (PCL) scaffold with modes of fiber distribution at 600 nm and 3.3 μm. Three conventional unimodal scaffolds with mean diameters of 300 nm and 2.6 and 5.2 μm, respectively, were used as controls to evaluate the new materials. Characterization of the microstructure (i.e. porosity, fiber distribution and pore structure) and mechanical properties (i.e. stiffness, strength and failure mode) indicated that the multimodal scaffold had superior mechanical properties (Young's modulus ∼40 MPa and strength ∼1 MPa) in comparison with the controls, despite the large porosity (∼90% on average). A biological assessment was conducted with bone marrow stromal cell type (mesenchymal stem cells, mTERT-MSCs). While the new material compared favorably with the controls with respect to cell viability (on the outer surface), it outperformed them in terms of cell colonization within the scaffold. The latter result, which could neither be practically achieved in the controls nor expected based on current models of pore size distribution, demonstrated the greater openness of the pore structure of the bimodal material, which remarkably did not come at the expense of its mechanical properties. Furthermore, nanofibers were seen to form a nanoweb bridging across neighboring microfibers, which boosted cell motility and survival. Lastly, standard adipogenic and osteogenic differentiation tests served to demonstrate that the new scaffold did not hinder the multilineage potential of stem cells. © 2009 Acta Materialia Inc

    Effect of tannin supplementation on nitrogen digestibility and retention in growing pigs.

    Get PDF
    Two levels (0.25% and 0.5%) of water soluble chestnut tannin were added to the diet of growing pigs in a 40 days feeding trial, from the average body weight of 76kg up to about 110kg. As expected, a significant depression of the apparent digestibility of both dietary dry matter and nitrogen was recorded with level 0.5%, but the decrease of retained nitrogen was not statistically significant, due to the higher dietary nitrogen. It is concluded that the present preliminary study showed that a concentration of 250g tannin per 100kg mixed feed does not appreciably influence the animals' performance. The aspect of a possible beneficial effect on the gut microflora deserves further studies

    Effect of forage /concentrate ratio and soybean oil supplementation on in vitro fatty acid profile of sheep rumen liquor.

    Get PDF
    In an in vitro trial, the effect of forage/concentrate ratio (F/C) and soybean oil (SO) supplementation on rumen liquor fatty acids profile was studied with the aim to evaluate changes in the profiles of biohydrogenation intermediates during the fermentation process. Feed samples of four diets were inoculated with sheep rumen liquor: i) high F/C and no SO; ii) high F/C and SO; iii) low F/C and no SO; iv) low F/C and SO. Fermentation times were 6, 12 h. Trans fatty acid were formed when oil supplement or a low forage content were present in the diets, but at different times of fermentation, as a consequence of a shift from the usual rumen biohydrogenation pathway. In fact, when a higher forage percentage was included in the diet, the alternative pathways of rumen biohydrogenation did not occur; trans10 C18:1 concentration was low and neither trans10, cis12 CLA nor trans, trans CLA appeared

    Monobutirryne: a novel feed additive in the diet of broiler chickens.

    Get PDF
    Purpose of the present work was to validate the monoglyceride of butyric acid (MB) as an alternative to antibiotics as growth promoters in the diet of broiler chickens. The approach is a kind of prolongation of previous works, in which a blend of mono-, di- and tri-glycerides of butyric acid have been previously tested. The results indicated that MB was very efficient in limiting the mortality of birds challenged with Eimeria spp., but did not appreciably impair the performance of unchallenged birds. In conclusion, the metabolisable energy content of MB appeared comparable with that of soybean oil and MB a reliable coccidiostat

    Effect of oleic and conjigated linoleic acid in diet of broiler chickens on the live growth performances, carcass traits and meat fatty acid profile

    Get PDF
    Olive oil and CLA enriched olive oil were compared with each other in a growth trial with broiler chickens, as energy supplements to the diet. A commercial CLA blend was used at the level of 1 kg per 100 kg mixed integrated feed. Two hundred and forty commercial hybrid broilers (Ross 308) were randomly subdivided and allotted to 8 pens of 30 birds each. Four pens of birds were fed the olive oil diet and considered the control group; the other 4 pens were fed the olive oil supplemented with CLA and considered the treated group. The experiment lasted 47 days. The live performance of the treated birds resulted different from the performance of the control ones: the final body weight was slightly lighter (2.544 kg vs 2.639 kg; P≤0.05) with a lower feed intake (4.886 kg feed vs 4.998 kg, P≤0.05) and, of course, an almost perfectly overlapping feed/gain ratio (1.90 vs 1.91). The fatty acid composition of the breast fat of the CLA treated birds resulted enriched by the two major CLA isomers, trans 10 cis 12 and cis 9 trans 11, whereas oleic acid and the linoleic, linolenic and arachidonic polyunsaturated acids showed a decrease (P≤0.05). CLA appears a recommendable ingredient in the diets of broilers as it improves the beneficial characteristics of poultry meat

    Transfer of dietary fatty acids from butyric acid fortified canola oil into the meat of broilers

    Get PDF
    The literature reported positive beneficial effects of butyric acid and canola oil on production performance traits of broiler chickens. Three hundred hybrid Ross 708 (150 males and 150 females) were randomly allotted to 10 pens per treatment with 5 males and 5 females per pen. Ten pens were administered a diet supplemented with soybean oil (control), ten pens the same basal diet but supplemented with a blend of mono-, di-, tri-glyceride of butyric acid added to soybean oil (T1) and ten pens the same basal diet supplemented with a mix of soybean and canola oil containing butyrate (T2). No differences in final body weight, dressing percentage, liver and thigh weight were found between groups. The T2 birds showed the highest feed/gain ratio (P<0.05). The control group showed the highest value for breast weight while the highest quantity of abdominal fat was in T2 carcasses. Fatty acid profile was significantly influenced by the presence of oil supplements, not only quantitatively but also qualitatively

    Mixture of mono- di- and tri-glycerides as energy supplements to broilers diets.

    Get PDF
    Mixtures of mono-, di- and tri-glycerides from olive oil (MDT) were added to: palm oil (PO), olive oil (OO), soybean oil (SO), free fatty acids from palm oil (PFA), free fatty acids from olive oil (OFA). The compound mixtures were used as energy supplements in the diets of broiler chickens in comparison with plain SO and plain animal fat (AF). Two hundred and ten birds were randomly allotted to 7 dietary treatments with the diverse oil sources: 6 birds per cage, 5 cages per treatment. The effects of the treatments on growth rates, feed/gain ratios and acidic composition of abdominal fat of hybrid Ross 308 female chickens were studied. The animals were slaughtered at the end of the trial, at day 35. The breast meat quality was then evaluated by a panel of 15 trained members and analysed for shelf life duration. The AF treatment gave the highest weight gain, but only in the first week. MDT + OO (50/50) resulted the best combination, with slight, non significant, better performances and a decidedly better quality in terms of acidic composition of abdominal fat, taste and juiciness of breast meat and shelf lif
    corecore