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  • 1
    Publication Date: 2018-07-05
    Description: Publication date: July 2018 Source: Heliyon, Volume 4, Issue 7 Author(s): Gabrielle Gauvin-Rossignol, Philippe Legros, Jean Ruel, Marc-André Fortin, André Bégin-Drolet Alginate-based hydrogels are widely used for the development of biomedical scaffolds in regenerative medicine. The use of sugar glass as a sacrificial template for fluidic channels fabrication within alginate scaffolds remains a challenge because of the premature dissolution of sugar by the water contained in the alginate as well as the relatively slow internal gelation rate of the alginate. Here, a new and simple method, based on a sugar glass fugitive ink loaded with calcium chloride to build sacrificial molds, is presented. We used a dual calcium cross-linking process by adding this highly soluble calcium source in the printed sugar, thus allowing the rapid gelation of a thin membrane of alginate around the sugar construct, followed by the addition of calcium carbonate and gluconic acid δ-lactone to complete the process. This innovative technique results in the rapid formation of "on-demand" alginate hydrogel with complex fluidic channels that could be used in biomedical applications such as highly vascularized scaffolds promoting pathways for nutrients and oxygen to the cells.
    Electronic ISSN: 2405-8440
    Topics: Natural Sciences in General
    Published by Elsevier
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  • 2
    Publication Date: 2018-07-05
    Description: Publication date: July 2018 Source: Heliyon, Volume 4, Issue 7 Author(s): Mohun Ramratnam, Barrett Kenny, John W. Kyle, Brandi Wiedmeyer, Timothy A. Hacker, David Y. Barefield, Elizabeth M. McNally, Jonathan C. Makielski ATP-sensitive potassium channels found in both the sarcolemma (sarcK ATP ) and mitochondria (mitoK ATP ) of cardiomyocytes are important mediators of cardioprotection during ischemic heart disease. Sulfonylurea receptor isoforms (SUR2), encoded by Abcc9 , an ATP-binding cassette family member, form regulatory subunits of the sarcK ATP channel and are also thought to regulate mitoK ATP channel activity. A short-form splice variant of SUR2 (SUR2A-55) was previously shown to target mitochondria and display diaxoxide and ATP insensitive K ATP activity when co-expressed with the inward rectifier channels Kir6.2 and Kir6.1. We hypothesized that mice with cardiac specific overexpression of SUR2A-55 would mediate cardioprotection from ischemia by altering mitoK ATP properties. Mice overexpressing SUR2A-55 (TG SUR2A-55 ) in cardiomyocytes were generated and showed no significant difference in echocardiographic measured chamber dimension, percent fractional shortening, heart to body weight ratio, or gross histologic features compared to normal mice at 11–14 weeks of age. TG SUR2A-55 had improved hemodynamic functional recovery and smaller infarct size after ischemia reperfusion injury compared to WT mice in an isolated hanging heart model. The mitochondrial membrane potential of TG SUR2A-55 mice was less sensitive to ATP, diazoxide, and Ca 2+ loading. These data suggest that the SUR2A-55 splice variant favorably affects mitochondrial function leading to cardioprotection. These data support a role for the regulation of mitoK ATP activity by SUR2A-55.
    Electronic ISSN: 2405-8440
    Topics: Natural Sciences in General
    Published by Elsevier
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  • 3
    Publication Date: 2018-07-05
    Description: Publication date: July 2018 Source: Heliyon, Volume 4, Issue 7 Author(s): Dilli Ram Thapa, Xiaxin Tao, Feng Fan, Zhengru Tao On 25 April 2015, a large earthquake with moment - magnitude (M w ) 7.8 occurred at Gorkha (latitude 28.23° N and longitude 84.73° E) in Central Nepal. Just 17 days later, another large earthquake of M w 7.3 occurred at Dolakha (latitude 27.80° N and longitude 86.06° E), about 140 km away from the previous epicenter. In this study, we deal with the aftershocks of these two earthquakes that occurred in the region (27°–28.5°N, 84°–87°E) spanning the period from 25 April 2015 to 28 May 2016 to find the spatiotemporal distribution patterns, the size distribution ( b -value), and the aftershock decay rate ( p -value) of this sequence. Aftershock epicenters of the 2015 Gorkha-Dolakha earthquake doublet are distributed over an area approximately 170 km in length and 70 km in width and largely confined in a depth range from 5 to 25 km. The spatial distribution of epicenters and known geological structures in this study reveals that aftershocks are limited on the east by the surface trace of the Everest lineament and on the south side by the surface trace of the segment of the Main Boundary Thrust (MBT). The estimated b- and p- values of this seismic sequence are 0.93 ± 0.03 and 0.79 ± 0.24, respectively. This b- value is higher than the b- value estimated by the previous studies, while the p- value corresponds in general with the p- value obtained by recent study in the region.
    Electronic ISSN: 2405-8440
    Topics: Natural Sciences in General
    Published by Elsevier
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  • 4
    Publication Date: 2018-07-05
    Description: Publication date: July 2018 Source: Heliyon, Volume 4, Issue 7 Author(s): Arisa Sakamoto, Rui Yamaguchi, Reona Yamaguchi, Shinji Narahara, Hiroyuki Sugiuchi, Yasuo Yamaguchi RANTES is a key chemokine for atherosclerosis, and obesity is associated with progression of atherosclerosis. Substance P (SP) increases glucose uptake and accumulation of lipids in adipocytes, and SP may upregulate RANTES expression. This study investigated the mechanism of RANTES expression by human M1 macrophages stimulated with SP. SP upregulated RANTES protein expression, whereas aprepitant (an NK1R antagonist) blunted this response. Pretreatment of macrophages with BIRB796 (a combined p38γ/p38δ inhibitor) led to a significant decrease of RANTES expression. Next, we investigated the effect of several NK1R internalization factors on RANTES expression, including GRK2, β-arrestin 2, dynamin, ROCK, and TGFβ1. Exposure of macrophages to SP upregulated TGFβ1 expression. Silencing of β-arrestin 2 or GRK2 significantly enhanced the RANTES protein level after stimulation by SP, whereas TGFβ1/2/3 siRNA or dynasore (a dynamin inhibitor) decreased RANTES and Y-27632 (a ROCK inhibitor) had no effect. Surprisingly, silencing of transcription factor specificity protein 1 (Sp1) or inhibition of Sp1 activity by mithramycin led to significant upregulation of TGFβ1 protein and corresponding enhancement of RANTES expression (by ELISA or western blotting), whereas siRNA for C/EBPβ attenuated expression of both TGFβ1 and RANTES. Next, we investigated transcriptional cross-talk among Sp1 and C/EBPβ, TIF1β, or Fli-1 in relation to RANTES expression. Compared with TIF1β or Fli-1 siRNA, C/EBPβ siRNA showed significantly stronger inhibition of RANTES production by Sp1 siRNA-transfected macrophages after stimulation with SP. In conclusion, transcription factor Sp1 engages in cross-talk with C/EBPβ and modulates TGFβ1 production to negatively regulate RANTES expression in macrophages stimulated with SP. In conclusion, cross-talk between the transcription factor Sp1 and C/EBPβ modulates TGFβ1 production to negatively regulate expression of the atherogenic chemokine RANTES in SP-stimulated macrophages, while RANTES is upregulated by SP via the p38γδMAPK/C/EBPβ/TGFβ1 signaling pathway.
    Electronic ISSN: 2405-8440
    Topics: Natural Sciences in General
    Published by Elsevier
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  • 5
    Publication Date: 2018-07-05
    Description: Publication date: July 2018 Source: Heliyon, Volume 4, Issue 7 Author(s): Sonia Podvin, Aneta Wojnicz, Vivian Hook Proteases are required to generate active peptide neurotransmitters, known as neuropeptides, from pro-neuropeptides. Model animal systems have recently illustrated roles for the cathepsin V (CTSV) and cathepsin L (CTSL) cysteine proteases, combined with the serine proteases PC1/3 (PCSK1) and PC2 (PCSK2), and exopeptidases in the production of neuropeptides. There is notable interest in the human-specific cathepsin V gene which is not present in rodent and other animal models used in prior studies of neuropeptide production. A gap in the field is knowledge of the human brain gene expression patterns of these neuropeptide-producing protease systems. Therefore, the goal of this study was to characterize the expression profiles of these pro-neuropeptide processing proteases in human brain. Quantitative gene expression microarray data for 169 human brain regions was obtained from the Allen Institute Human Brain Atlas resource, analyzed as log 2 of gene expression intensity normalized to the mean of human genes (21,245 genes) expressed in human brain. These proteases had log 2 values of 2–12, indicating expression levels above the average of all genes in the human brain, with varying expression levels among the 169 brain regions. CTSV and CTSL displayed moderate to high expression values of 1.9–8.6 and 7.1–10.6, respectively. Interestingly, CTSV and CTSL showed high expression in white matter composed of myelinated axons, consistent with the knowledge that neuropeptide production occurs in axons within transported neuropeptide secretory vesicles to nerve terminals. PCSK1 had a broad range of moderate to very high expression with log 2 of 2–12. PCSK2 had somewhat lower expression levels than PCSK1. The exopeptidase genes RNPEP, CTSH, and CPE each showed fairly even levels of expression throughout the brain, with CPE displaying high expression. The prevalence of these processing proteases throughout human brain regions, including areas rich in neuropeptides such as hypothalamus, is consistent with their roles for neuropeptide production. Further, proenkephalin and NPY precursors, substrates of CTSV and CTSL shown in prior model animal studies, were co-expressed with CTSV and CTSL. These data demonstrate that the human brain expresses the neuropeptide-producing cysteine and serine proteases, with exopeptidases, throughout a multitude of brain regions.
    Electronic ISSN: 2405-8440
    Topics: Natural Sciences in General
    Published by Elsevier
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  • 6
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    Elsevier
    In: Heliyon
    Publication Date: 2018-07-04
    Description: Publication date: July 2018 Source: Heliyon, Volume 4, Issue 7 Author(s): Elias E. Elemike, Henry U. Nwankwo, Damian C. Onwudiwe Three Schiff base compounds, N 1 ,N 2 -bis(3-nitrobenzylidene)phenylene diamine (NBBA), 2-methyl- N -(3-nitrobenzylidene)aniline (MNBA) and N -(2-chlorobenzylidene)-4-nitroaniline (CBNA) were synthesized, characterised and applied for the first time as potential mild steel (MS) corrosion inhibitors in 1 M HCl at 30 °C. Fourier transform infra-red (FTIR), 1 H, 13 C Nuclear magnetic resonance (NMR) and Mass spectrometry (MS) were used for the characterisation of the compounds. The electrochemical studies and evaluation of corrosion inhibition potency were achieved using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. Density functional theory (DFT) calculations were further employed to describe the electronic distribution on the molecules and potential sites that aided corrosion inhibition. The results of the employed characterisation techniques confirmed the proposed structures of the compounds with the MS revealing the exact molecular mass of the compounds. Electrochemical results showed that the trend in inhibition efficiency of the three compounds was in the order: MNBA > NBBA > CBNA. MNBA recorded the highest inhibition efficiency at 100 ppm. Corrosion kinetics of the set of inhibitors was found to prefer the Langmuir adsorption isotherm with both physisorption and chemisorption mechanisms as revealed by ΔG values. In an effort to develop efficient corrosion inhibitors with non-toxic effect, low cost and multiple adsorption centres, these Schiff bases are presented.
    Electronic ISSN: 2405-8440
    Topics: Natural Sciences in General
    Published by Elsevier
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  • 7
    Publication Date: 2018-07-01
    Description: Publication date: June 2018 Source: Heliyon, Volume 4, Issue 6 Author(s): Jenifer Trepiana, M. Begoña Ruiz-Larrea, José Ignacio Ruiz-Sanz Currently natural products derived from plants are receiving huge attention because of their antitumor activities. In previous work we reported that an aqueous leaf extract of Vismia baccifera induced toxicity in HepG2. The present study focuses on the mechanisms of the cytotoxic actions induced by the extract. Results showed that V. baccifera was innocuous in non-transformed human HH4 hepatocytes. In HepG2 it caused deregulation of antioxidant status (increasing superoxide dismutase expression and decreasing glutathione levels and glutathione peroxidase activity) and accumulation of reactive oxygen species, particularly hydrogen peroxide. The extract induced a) cell cycle arrest at G 2 /M phase, b) phosphorylation of ATM (protein kinase ataxia-telangiectasia mutated) and γH2AX (γ-histone family 2A variant), c) caspase-3 activation, and e) deregulation of the Bax/Bcl family, increasing pro-apoptotic proteins. ATM did not seem to be involved in γH2AX activation. Co-incubation with catalase prevented the alterations elicited by V. baccifera in HepG2. Taking together, these results indicate that hydrogen peroxide mediates the HepG2 cytotoxic response and provide evidence for more in-depth studies of the signaling involved.
    Electronic ISSN: 2405-8440
    Topics: Natural Sciences in General
    Published by Elsevier
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  • 8
    Publication Date: 2018-06-30
    Description: Publication date: June 2018 Source: Heliyon, Volume 4, Issue 6 Author(s): Sarah A. Johnson, Mark R. Ellersieck, Cheryl S. Rosenfeld Bisphenol A (BPA) is a pervasive industrial chemical used in many common household items. To examine how early exposure to BPA and ethinyl estradiol (EE, estrogen in birth control pill) might affect biparental care, effects of these chemicals in male and female California mice ( Peromyscus californicus ), who are monogamous and biparental, were examined. California mice exposed during pre- and peri-natal life to BPA at an environmentally relevant concentration or EE show later disrupted biparental behaviors. The hypothalamus is an important brain region for regulating parental behaviors. Thus, it was hypothesized compromised biparental care might be partially due to hypothalamic gene alterations. To address this question, brains from F 1 parenting female and male California mice from controls, BPA- and EE-exposed groups were collected at postnatal day (PND) 2, and RNA was isolated from hypothalamic micropunches. Gene expression was examined in this brain region for genes affected by BPA exposure and attributed to governing parental care in rodents and humans. BPA-exposed California mice showed increased hypothalamic expression of Kiss1, Esr1 and Esr2 relative to AIN control and EE-exposed parents in the case of Esr2 . Notably, current studies represent the first report to show that early exposure to BPA can induce longstanding effects on hypothalamic gene expression in parenting male and female rodents. Absence of such hypothalamic gene expression changes in EE-exposed parents indicates early BPA exposure may induce later transcriptomic effects through estrogen receptor-independent pathways. BPA-driven changes in hypothalamic function of California mice might contribute to decreased biparental investment, which could result in F 2 multigenerational effects.
    Electronic ISSN: 2405-8440
    Topics: Natural Sciences in General
    Published by Elsevier
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  • 9
    Publication Date: 2018-06-30
    Description: Publication date: June 2018 Source: Heliyon, Volume 4, Issue 6 Author(s): Kazuko Shichijo, Toshihiro Takatsuji, Manabu Fukumoto, Masahiro Nakashima, Mutsumi M. Matsuyama, Ichiro Sekine Background Radiation doses received by Hiroshima and Nagasaki atomic bomb survivors has been evaluated from data related only to external exposure because there was no reliable evidence for internal exposure in atomic bomb victims. However, we assumed that the contribution of internal exposure cannot be ruled out. Methods Autoradiography was carried out with the 70-year old paraffin-embedded specimens taken from Nagasaki atomic bomb victims who died within 5 months after the bombing. After exposure to photo emulsion for 6 months alpha-tracks were revealed in the specimens. We confirmed the alpha-tracks were emitted from deposited plutonium (Pu) in reference to the track length of the 8.787 MeV alpha-particle of thorium series from Polonium-212. Radioactivity concentration of Pu was obtained by counting alpha-tracks. The absorbed dose of each cell nucleus penetrated by an alpha-particle was estimated by calculating the absorbed energy from the particle. Results Using old paraffin embedded sections processed about 70 years ago, we demonstrated for the first time that conditions in the aftermath of the bombing led to internal exposure to alpha-particles emitted from Pu, the fissile material of the Nagasaki atomic bomb. Dose rate of internal exposure was higher in the victims exposed outdoors than those indoors. Radioactivity concentration was relatively uniform among organs examined in a victim. Conclusion Pu was deposited in the bodies of the Nagasaki A-bomb victims presumably via various routes. Organ dose from Pu of the Nagasaki A-bomb victims studied was during their surviving period, which is lower compared with external exposure. However, the impact to the individual cell nucleus by a single alpha-particle might not be negligible, It would be meaningful; to analyze the relationship of the impact of internal exposure at the cellular level and organ dose. The 70-year old pathological specimens utilized in our study are an invaluable source for understanding internal radiation exposure and are crucial in elucidating experimentally unreproducible phenomena.
    Electronic ISSN: 2405-8440
    Topics: Natural Sciences in General
    Published by Elsevier
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  • 10
    Publication Date: 2018-06-30
    Description: Publication date: June 2018 Source: Heliyon, Volume 4, Issue 6 Author(s): Ramon Guirado, Héctor Carceller, Esther Castillo-Gómez, Eero Castrén, Juan Nacher The quantification of the expression of different molecules is a key question in both basic and applied sciences. While protein quantification through molecular techniques leads to the loss of spatial information and resolution, immunohistochemistry is usually associated with time-consuming image analysis and human bias. In addition, the scarce automatic software analysis is often proprietary and expensive and relies on a fixed threshold binarization. Here we describe and share a set of macros ready for automated fluorescence analysis of large batches of fixed tissue samples using FIJI/ImageJ. The quantification of the molecules of interest are based on an automatic threshold analysis of immunofluorescence images to automatically identify the top brightest structures of each image. These macros measure several parameters commonly quantified in basic neuroscience research, such as neuropil density and fluorescence intensity of synaptic puncta, perisomatic innervation and col-localization of different molecules and analysis of the neurochemical phenotype of neuronal subpopulations. In addition, these same macro functions can be easily modified to improve similar analysis of fluorescent probes in human biopsies for diagnostic purposes based on the expression patterns of several molecules.
    Electronic ISSN: 2405-8440
    Topics: Natural Sciences in General
    Published by Elsevier
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