331 research outputs found

    Nicotinamide inhibits melanoma in vitro and in vivo

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    Background: Even though new therapies are available against melanoma, novel approaches are needed to overcome resistance and high-toxicity issues. In the present study the anti-melanoma activity of Nicotinamide (NAM), the amide form of Niacin, was assessed in vitro and in vivo. Methods: Human (A375, SK-MEL-28) and mouse (B16-F10) melanoma cell lines were used for in vitro investigations. Viability, cell-death, cell-cycle distribution, apoptosis, Nicotinamide Adenine Dinucleotide+ (NAD+), Adenosine Triphosphate (ATP), and Reactive Oxygen Species (ROS) levels were measured after NAM treatment. NAM anti-SIRT2 activity was tested in vitro; SIRT2 expression level was investigated by in silico transcriptomic analyses. Melanoma growth in vivo was measured in thirty-five C57BL/6 mice injected subcutaneously with B16-F10 melanoma cells and treated intraperitoneally with NAM. Interferon (IFN)-γ-secreting murine cells were counted with ELISPOT assay. Cytokine/chemokine plasmatic levels were measured by xMAP technology. Niacin receptors expression in human melanoma samples was also investigated by in silico transcriptomic analyses. Results: NAM reduced up to 90% melanoma cell number and induced: I) accumulation in G1-phase (40% increase), ii) reduction in S- A nd G2-phase (about 50% decrease), iii) a 10-fold increase of cell-death and 2.5-fold increase of apoptosis in sub-G1 phase, iv) a significant increase of NAD+, ATP, and ROS levels, v) a strong inhibition of SIRT2 activity in vitro. NAM significantly delayed tumor growth in vivo (p ≤ 0.0005) and improved survival of melanoma-bearing mice (p ≤ 0.0001). About 3-fold increase (p ≤ 0.05) of Interferon-gamma (IFN-γ) producing cells was observed in NAM treated mice. The plasmatic expression levels of 6 cytokines (namely: Interleukin 5 (IL-5), Eotaxin, Interleukin 12 (p40) (IL12(p40)), Interleukin 3 (IL-3), Interleukin 10 (IL-10) and Regulated on Activation Normal T Expressed and Secreted (RANTES) were significantly changed in the blood of NAM treated mice, suggesting a key role of the immune response. The observed inhibitory effect of NAM on SIRT2 enzymatic activity confirmed previous evidence; we show here that SIRT2 expression is significantly increased in melanoma and inversely related to melanoma-patients survival. Finally, we show for the first time that the expression levels of Niacin receptors HCAR2 and HCAR3 is almost abolished in human melanoma samples. Conclusion: NAM shows a relevant anti-melanoma activity in vitro and in vivo and is a suitable candidate for further clinical investigations

    Measurement of photoemission and secondary emission from laboratory dust grains

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    The overall goal of this project is experimentally determine the emission properties of dust grains in order to provide theorists and modelers with an accurate data base to use in codes that predict the charging of grains in various plasma environments encountered in the magnetospheres of the planets. In general these modelers use values which have been measured on planar, bulk samples of the materials in question. The large enhancements expected due to the small size of grains can have a dramatic impact upon the predictions and the ultimate utility of these predictions. The first experimental measurement of energy resolved profiles of the secondary electron emission coefficient, 6, of sub-micron diameter particles has been accomplished. Bismuth particles in the size range of .022 to .165 micrometers were generated in a moderate pressure vacuum oven (average size is a function of oven temperature and pressure) and introduced into a high vacuum chamber where they interacted with a high energy electron beam (0.4 to 20 keV). Large enhancements in emission were observed with a peak value, delta(sub max) = 4. 5 measured for the ensemble of particles with a mean size of .022 micrometers. This is in contrast to the published value, delta(sub max) = 1.2, for bulk bismuth. The observed profiles are in general agreement with recent theoretical predictions made by Chow et al. at UCSD

    Injectable xyloglucan hydrogels incorporating spheroids of adipose stem cells for bone and cartilage regeneration

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    Cartilage or bone regeneration approaches based on the direct injection of mesenchymal stem cells (MSCs) at the lesion site encounter several challenges, related to uncontrolled cell spreading and differentiation, reduced cell viability and poor engrafting. This work presents a simple and versatile strategy based on the synergic combination of in-situ forming hydrogels and spheroids of adipose stem cells (SASCs) with great potential for minimally invasive regenerative interventions aimed to threat bone and cartilage defects. Aqueous dispersions of partially degalactosylated xyloglucan (dXG) are mixed with SASCs derived from liposuction and either a chondroinductive or an osteoinductive medium. The dispersions rapidly set into hydrogels when temperature is brought to 37 °C. The physico-chemical and mechanical properties of the hydrogels are controlled by polymer concentration. The hydrogels, during 21 day incubation at 37 °C, undergo significant structural rearrangements that support cell proliferation and spreading. In formulations containing 1%w dXG cell viability increases up to 300% for SASCs-derived osteoblasts and up to 1000% for SASCs-derived chondrocytes if compared with control 2D cultures. The successful differentiation into the target cells is supported by the expression of lineage-specific genes. Cell-cell and cell-matrix interactions are also investigated. All formulations resulted injectable, and the incorporated cells are fully viable after injection

    Porcine model for deep superior epigastric artery perforator flap harvesting: Anatomy and technique

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    BACKGROUND Microsurgical training on rats before starting with clinical practice is a well-established routine. Animal model training is less widespread for perforator flaps, although these flaps represent a technical challenge. Unlike other flaps, they require specific technical skills that need to be adequately trained on a living model 1 : a cadaver is not enough because no bleeding, vessel damage, or vasospasm can be simulated. 2 The purpose of this study was to assess the suitability of the porcine abdomen as a training model for the deep inferior epigastric artery perforator (DIEAP) flap, commonly used in human breast reconstruction. METHODS A female swine (Sus scrofa domesticus, ssp; weight 25kg) was used. The procedure was performed with the pig under general anesthesia and in the supine position. A deep superior epigastric artery perforator (DSEAP) flap was harvested on the left side of the abdomen, including the 3 cranial nipples and stopping in the midline to spare the contralateral flap for another dissection (as in bilateral breast reconstructions in humans; Fig. 1). All steps of a DIEAP harvest were simulated: superficial vein harvest, suprafascial perforator dissection, intramuscular perforator harvest with preservation of the nerves, and flap isolation. Observation of capillary refill was used to confirm flap viability at the end of the dissection. The procedure was recorded by means of a GoPro camera and simultaneously with a head mounted (4 7 magnification) Loupecam system. Photographs were taken using 2 cameras during surgery at relevant time points. RESULTS At the end of the dissection, the flap was viable. The subcutaneous adipose tissue of the pig is less represented than in human and pigs have an additional muscular layer, the panniculus carnosus, which is the analogue of the human Scarpa's fascia. The rectus fascia is thinner. The perforators are lined in 2 rows: 1 lateral and 1 medial, as in the DIEAP, and the intercostal nerves cross the vessels, as happens in humans. The porcine rectus abdominis muscle is thinner than the human one, but vessels' branching faithfully reproduces the human model. 1 We identified 5 perforating vessels of more than 1mm in diameter (2 lateral and 3 medial). We isolated a lateral perforator first and a medial one last: the latter was eventually used to nourish the flap (Fig. 2). CONCLUSIONS The DSEAP flap allows one to closely reproduce all the steps of DIEAP flap harvesting and also to carry out the intramuscular dissection of 2 perforators for each side (up to 4 for each animal), confirming the adequacy of this pig model for microsurgical training. The deep superior epigastric artery is dominant in pigs. 3 Despite this anatomical difference, the DSEAP allows one to reproduce the main steps of DIEAP flap harvesting, providing an excellent training model. Moreover, the presence of double perforating rows allows simulating the dissection twice on each side

    Analysis of sequence variability and transcriptional profile of cannabinoid synthase genes in cannabis sativa l. Chemotypes with a focus on cannabichromenic acid synthase

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    Cannabis sativa L. has been long cultivated for its narcotic potential due to the accumulation of tetrahydrocannabinolic acid (THCA) in female inflorescences, but nowadays its production for fiber, seeds, edible oil and bioactive compounds has spread throughout the world. However, some hemp varieties still accumulate traces of residual THCA close to the 0.20% limit set by European Union, despite the functional gene encoding for THCA synthase (THCAS) is lacking. Even if some hypotheses have been produced, studies are often in disagreement especially on the role of the cannabichromenic acid synthase (CBCAS). In this work a set of European Cannabis genotypes, representative of all chemotypes, were investigated from a chemical and molecular point of view. Highly specific primer pairs were developed to allow an accurate distinction of different cannabinoid synthases genes. In addition to their use as markers to detect the presence of CBCAS at genomic level, they allowed the analysis of transcriptional profiles in hemp or marijuana plants. While the high level of transcription of THCAS and cannabidiolic acid synthase (CBDAS) clearly reflects the chemical phenotype of the plants, the low but stable transcriptional level of CBCAS in all genotypes suggests that these genes are active and might contribute to the final amount of cannabinoids

    Hydrogel scaffolds based on k-Carrageenan/xyloglucan blends to host spheroids from human adipose stem cells

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    Hydrogels are water-swollen networks of hydrophilic polymer. They can be fabricated in various shapes and swell in water or aqueous solutions maintaining their original shape or undergo progressive erosion; can exibit large volume phase transitions with the change of one environmental parameter (stimuli-responsivness), shock absorption and low sliding friction properties (1). The morphology and mechanical properties of hydrogels are strongly affected by the network composition, the nature and degree of crosslinking and the degree of swelling. Indeed, when hydrogels are designed as scaffolds for human tissues remodeling, they must have sufficient mechanical integrity to provide support to the cells from the time of implantation to the completion of the process. The large amount of water present in the hydrogels and its microscopic pores interconnectivity allows transportation of nutrients, oxygen and metabolites, that ensures cells viability, and permits cells migration and scaffold colonization. The polymeric network can immobilize biomolecules that may affect cells growth or differentiation, control drug release profiles and enzymatic degradation (2,3). The combination of two hydrogelforming polymers with different chemistries and crosslinking densities can be used to tailor the morphology, mechanical strength and toughness of the scaffold to meet specific requirements (1). This work investigates the physico-chemical, morphological and mechanical properties of hydrogels formed by the blend of two polysaccharides, k-Carrageenan (k-C) and Degalactosylated Xyloglucan (Deg-XG) undergoing salt-induced and temperature-induced solgel transition, respectively. It also studies the compatibility of the two biopolymers with spheroids from adipose-derived stem cells (S-ASCs) in the prospect of developing instructive scaffolds for use in regenerative medicine

    Progress in regional PV power forecasting: A sensitivity analysis on the Italian case study

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    The increasing penetration of PV generation, driven by climate strategies and objectives, calls for accurate production forecasting to mitigate the negative effects associated with inherent variability, such as overgeneration, grid instability, supplementary reserve request. The regional PV power forecasting is crucial for Transmission and Distribution system operators for a better management of energy flows. In this work many aspects of regional PV power forecasting are investigated, by means of a comparison of six different forecasting models applied to predict the hourly production of the following days on six Italian bidding zones for one year. In particular, the work shows that the forecasting accuracy is mainly affected by the algorithm and its pre and post processing, with a range of 30% in performance accuracy, while it is less impacted by the forecasting horizon. It has been verified that the accuracy in the irra- diation prediction, used in input to the power forecasting algorithm, has less impact compared to single plants. The work confirms the performance improvement which can be obtained by increasing the size of the area to which the prediction refers, through a comparison between the forecasting at bidding zone and national level. Finally, we show that the larger the controlled forecast area, the smaller the impact on the forecast accuracy due to the non-uniform spatial and capacity distribution of the PV fleet. This means that as the size of the region increases, the average irradiance progressively becomes the best PV power predictor. We refer to this phenomenon as: “input smoothing effect"

    A Superspace Formulation of The BV Action for Higher Derivative Theories

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    We first analyze the anti-BRST and double BRST structures of a certain higher derivative theory that has been known to possess BRST symmetry associated with its higher derivative structure. We discuss the invariance of this theory under shift symmetry in the Batalin Vilkovisky (BV) formalism. We show that the action for this theory can be written in a manifestly extended BRST invariant manner in superspace formalism using one Grassmann coordinate. It can also be written in a manifestly extended BRST invariant manner and on-shell manifestly extended anti-BRST invariant manner in superspace formalism using two Grassmann coordinates.Comment: accepted for publication in EPJ

    Hydrogel scaffolds blends to host Spheroids from human adipose stem cells

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    INTRODUCTION Adipose stem cells represent a reliable source of stem cells for their widely demonstrated potential in regenerative medicine and tissue engineering applications. New recent insights show that 3D models may properly mimic the native tissue properties; in fact Spheroids from Adipose derived Stem Cells (S-ASCs) displayed enhanced regenerative abilities if compared to 2D models. Stem cell therapy success is determined by "cell-quality" thus the involvement of stress signals and cellular aging need to be deeply investigated. The development of 3D cell-laden hydrogels has enabled to mimic the peculiar scenario of a native tissue. We studied SASCs-cell quality and tested their viability and differentiation abilities in new hydrogels. METHODS S-ASCs were obtained from liposuction of healthy patients. Analysis of aging, telomeric length and stress-oxidative genes was performed through Real-Time PCR. Physico-chemical, morphological and mechanical properties of k-Carrageenan (k-C, 2%w) and degalactosylated xyloglucan (Deg-XG, 2%w) hydrogels were defined. S-ASCs compatibility with hydrogels was evaluated by viability test and mesenchymal differentiation abilities. RESULTS Gene expression of genes linked with stemness, senescence and stress-oxidative was evaluated and correlated with SASCs-cell quality. Indeed, aging-related p16INK4a mRNA is downregulated while anti-aging Sirtuin1 is upregulated in 3D-SASCs. Furthermore, vegetal-origin hydrogels have guaranteed an optimal environment for S-ASCs in stemness and mesenchymal differentiation conditions. CONCLUSION Bio-instructive scaffolds are critical for exploiting stem cells therapeutic potential in tissue engineering. This study provides a versatile approach to investigate the interactions between cells in controlled settings, opening up novel 3D in vitro approaches to mimic the tissues complexity
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