31 results on '"Namvar S"'
Search Results
2. Serum interleukin-6 and interleukin-10 responses in patients after major trauma: a prospective observational two centre study
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Jones, M., primary, Hanison, J., additional, Apreutesei, R., additional, Allarakia, B., additional, Namvar, S., additional, Ramaswamy, D. S., additional, Horner, D., additional, Smyth, L., additional, Body, R., additional, Columb, M., additional, Nirmalan, M., additional, and Nirmalan, N., additional
- Published
- 2022
- Full Text
- View/download PDF
3. Aspergillus fumigatus proteases, Asp f 5 and Asp f 13, are essential for airway inflammation and remodelling in a murine inhalation model
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Namvar, S., Warn, P., Farnell, E., Bromley, M., Fraczek, M., Bowyer, P., and Herrick, S.
- Published
- 2015
- Full Text
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4. Endothelin-1 mediates Aspergillus fumigatus induced airway inflammation and remodelling
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Labram, B, Namvar, S, Hussell, T, and Herrick, SE
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Aspergillus fumigatus ,endothelin-1 ,airway epithelium ,remodelling ,asthma ,respiratory tract diseases - Abstract
BACKGROUND: Asthma is a chronic inflammatory condition of the airways and patients sensitised to airborne fungi such as Aspergillus fumigatus have more severe asthma. Thickening of the bronchial subepithelial layer is a contributing factor to asthma severity for which no current treatment exists. Airway epithelium acts as an initial defence barrier to inhaled spores, orchestrating an inflammatory response and contributing to subepithelial fibrosis.\ud OBJECTIVE: We aimed to analyse the production of profibrogenic factors by airway epithelium in response to A. fumigatus, in order to propose novel anti-fibrotic strategies for fungal-induced asthma.\ud METHODS: We assessed the induction of key profibrogenic factors, TGFβ1, TGFβ2, periostin and endothelin-1, by human airway epithelial cells and in mice exposed to A. fumigatus spores or secreted fungal factors.\ud RESULTS: A. fumigatus specifically caused production of endothelin-1 by epithelial cells in vitro but not any of the other profibrogenic factors assessed. A. fumigatus also induced endothelin-1 in murine lungs, associated with extensive inflammation and airway wall remodelling. Using a selective endothelin-1 receptor antagonist, we demonstrated for the first time, that endothelin-1 drives many features of airway wall remodelling and inflammation elicited by A. fumigatus.\ud CONCLUSION: Our findings are consistent with the hypothesis that elevated endothelin-1 levels contribute to subepithelial thickening and highlight this factor as a possible therapeutic target for difficult-to-treat fungal-induced asthma.
- Published
- 2019
5. Functional molecules in mesothelial to mesenchymal transition revealed by transcriptome analyses
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Namvar, S, Woolf, AS, Zeef, LAH, Wilm, T, Wilm, B, and Herrick, SE
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mental disorders - Abstract
Peritoneal fibrosis is a common complication of abdominal and pelvic surgery, and can also be triggered by peritoneal dialysis, resulting in treatment failure. In these settings, fibrosis is driven by activated myofibroblasts that are considered to be partly derived by mesothelial‐to‐mesenchymal transition (MMT). We hypothesized that, if the molecular signature of MMT could be better defined, these insights could be exploited to block this pathological cellular transition. Rat peritoneal mesothelial cells were purified by the use of an antibody against HBME1, a protein present on mesothelial cell microvilli, and streptavidin nanobead technology. After exposure of sorted cells to a well‐known mediator of MMT, transforming growth factor (TGF)‐β1, RNA sequencing was undertaken to define the transcriptomes of mesothelial cells before and during early‐phase MMT. MMT was associated with dysregulation of transcripts encoding molecules involved in insulin‐like growth factor (IGF) and bone morphogenetic protein (BMP) signalling. The application of either recombinant BMP4 or IGF‐binding protein 4 (IGFBP4) ameliorated TGF‐β1‐induced MMT in culture, as judged from the retention of epithelial morphological and molecular phenotypes, and reduced migration. Furthermore, peritoneal tissue from peritoneal dialysis patients showed less prominent immunostaining than control tissue for IGFBP4 and BMP4 on the peritoneal surface. In a mouse model of TGF‐β1‐induced peritoneal thickening, BMP4 immunostaining on the peritoneal surface was attenuated as compared with healthy controls. Finally, genetic lineage tracing of mesothelial cells was used in mice with peritoneal injury. In this model, administration of BMP4 ameliorated the injury‐induced shape change and migration of mesothelial cells. Our findings demonstrate a distinctive MMT signature, and highlight the therapeutic potential for BMP4, and possibly IGFBP4, to reduce MMT.
- Published
- 2018
6. Why is the electroanalytical performance of carbon paste electrodes involving an ionic liquid binder higher than paraffinic binders? A simulation investigation
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Ghatee, M. H., primary, Namvar, S., additional, Zolghadr, A. R., additional, and Moosavi, F., additional
- Published
- 2015
- Full Text
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7. Implementation of SMC averaging method in a channeled molecular flow of liquids and gases
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Karimian, S M H, primary and Namvar, S, additional
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- 2012
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8. Detailed investigation on the effect of wall spring stiffness on velocity profile in molecular dynamics simulation
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Namvar, S, primary and Karimian, S M H, additional
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- 2012
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9. Are hypothalamic oscillators dysfunctional with high fat feeding?
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Namvar, S., primary, Gyte, A., additional, Birtles, S., additional, Leighton, B., additional, and Piggins, H., additional
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- 2008
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10. An ensemble of novel circadian oscillators in the mouse mediobasal hypothalamus
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Guilding, C., primary, Hughes, A., additional, Brown, T., additional, Namvar, S., additional, and Piggins, H., additional
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- 2008
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11. Endothelin 1 mediates Aspergillus fumigatus induced airway inflammation and remodelling in mouse inhalation model.
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Namvar, S., Labram, B., Hussell, T., and Herrick, S.
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- *
PREPROENDOTHELIN , *INHALATION injuries , *ASPERGILLUS fumigatus - Published
- 2019
12. Comparison of two methods for the treatment of primary pterygium: Amniotic membrane transplantation plus intraoperative mitomycin C, versus conjunctival rotational autograft plus intraoperative mitomycin C
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Jahadihosseini, H., Jamali, H., and Namvar, S.
13. Alterations of the expression of RGS4 and RGS10 proteins in the anticonvulsant effects of low frequency stimulation on perforant path kindling in adult male rats
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Namvar, S., Mirnajafi-Zadeh, J., Javan, M., and Maryam Zeraati
14. SPARC 2022 book of abstracts
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Ardo, A, Bass, J, Gaber, T, Abdullahi, A, Dargahi, T, Babaie, M, Bennett, A, Searle, D, Mbabu, A, Underwood, J, Munir, M, Woodman, A, Coffey, M, Cooper-Ryan, A, Foster, A, Greensmith, D, Stein, A, Dubrow-Marshall, R, Gumel, A, Malevicius, R, Rana, M, Baatz, A, Young, R, Bidgood, A, Davison, A, McDevitt, A, Rahimi Toudeshki, A, Parker, D, Price, C, Bird, S, Sabir, A, Withers, S, Latimer, J, Hamdan, A, Elkadi, H, Warburton, B, Kosmidou, S, Hiriart, J, Martin, C, Nourian, A, Nasr, G, Chinigo, C, Lisanti, M, Sotgia, F, Hargreaves, C, Newbery, S, Hall, B, Poolay Mootien, C, Beevers, D, Thompson, C, Lomas, M, Harris, D, Sharples, N, Gilbert, D, Cook, P, Allely, C, Mukherjee, R, Ajibade, D, Chen, Y, Watson, N, Maguire, D, Thompson, J, Vadera, S, Smith, E, Coscia, I, Cooper, E, Bown, K, Blezard, E, Clarke, A, Ahmed, A, Alkashti, F, Sharifi, S, Mtonga, V, Plahe, G, James, C, Goodhead, I, Elgamodi, H, Krpetic, Z, Broadhurst, H, Kolawole, H, Ferry, N, Bakoji, I, Nduka, I, Arrigo, R, Namvar, S, Homer, J, Mandal, J, Wood, M, Hutchinson, S, Mondal, D, Jackman, J, Sarwar, J, Howard, D, Kenney, L, Yuen, J, Roddy, J, Widdowson, M, Maloney yorganci, K, Coen, S, McMurty, L, Barnes, K, Magennis, C, Lineshah, L, Clarry, L, Long, T, Wood, A, Chrimes, L, Byrne, A, Stout, L, Stephens, M, Hashmi, F, Barton, L, Elliott, A, Smith, J, Irwin, L, Loi, M, O'Donnell, M, Sales, N, Gray, A, Kimamo, M, Fenton, A, Yousif, M, Alani, O, Hassunu Saleh, M, Takruri, H, Linge, N, Usman, N, Griffiths, M, Alam, M, Xu, O, Willis, A, Blaker, L, Gonen, P, Syme, R, Rafati, P, Abubakar, R, Ji, Y, Sam, R, Robinson, N, O'Chiobi, R, Kutar, M, Al Ben Jasim, S, Fitton, S, Talbot, R, Wilkie, I, Gowda, S, Fletcher, G, Webb, S, Halstead, T, Beech, D, Makarfi, U, Wu, Y, Brettle, A, Ure, C, Sant, A, Moftakhar, Z, Naeem, Z, Clark, A, Brown, T, Preece, S, Prasetyo, A, Benvenuto, C, Mariani, S, Murray, J, Ochoche, G, Lord, J, Bell, R, Shukla, K, Holderbaum, W, Theodoridis, T, Wei, G, Ritchie, M, Asdullah, M, Hazdifar, H, Taylor, T, Parnell, S, Yates, K, and Ireland, TJ
- Abstract
Welcome to the Book of Abstracts for the 2022 SPARC conference. Our conference is called “Moving \ud Forwards” reflecting our re-emergence from the pandemic and our desire to reconnect our PGR \ud community, in celebration of their research. PGRs have continued with their research endeavours \ud despite many challenges, and their ongoing successes are underpinned by the support and guidance \ud of dedicated supervisors and the Doctoral School Team. To recognise supervision excellence we will \ud be awarding our annual Supervisor of the Year prizes, based on the wonderful nominations received \ud from their PGR students.\ud Once again, we have received a tremendous contribution from our postgraduate research community; \ud with over 60 presenters, 12 Three-Minute Thesis finalists, and 20 poster presentations, the conference \ud showcases our extraordinarily vibrant, inclusive, and resilient PGR community at Salford. This year \ud there will be prizes to be won for ‘best in conference’ presentations, in addition to the winners from \ud each parallel session. Audience members too could be in for a treat, with judges handing out spot \ud prizes for the best questions asked, so don’t miss the opportunity to put your hand up. \ud These abstracts provide a taster of the diverse and impactful research in progress and provide \ud delegates with a reference point for networking and initiating critical debate. Take advantage of the \ud hybrid format: in online sessions by posting a comment or by messaging an author to say “Hello”, or \ud by initiating break time discussions about the amazing research you’ve seen if you are with us in \ud person. Who knows what might result from your conversation? With such wide-ranging topics being \ud showcased, we encourage you to take up this great opportunity to engage with researchers working \ud in different subject areas from your own. As recent events have shown, researchers need to \ud collaborate to meet global challenges. Interdisciplinary and international working is increasingly \ud recognised and rewarded by all major research funders. We do hope, therefore, that you will take this \ud opportunity to initiate interdisciplinary conversations with other researchers. A question or comment \ud from a different perspective can shed new light on a project and could lead to exciting collaborations, \ud and that is what SPARC is all about. \ud SPARC is part of a programme of personal and professional development opportunities offered to all \ud postgraduate researchers at Salford. More information about this programme is available on our \ud website: Doctoral School | University of Salford. Registered Salford students can access full details on \ud the Doctoral School hub: Doctoral School Hub - Home (sharepoint.com) You can follow us on Twitter \ud @SalfordPGRs and please use the #SPARC2022 to share your conference experience.\ud We particularly welcome taught students from our undergraduate and master’s programmes as \ud audience members. We hope you enjoy the presentations on offer and that they inspire you to pursue \ud your own research career. If you would like more information about studying for a PhD here at the \ud University of Salford, your lecturers can advise, or you can contact the relevant PGR Support Officer; \ud their details can be found at Doctoral School | University of Salford. \ud We wish you a rich and rewarding conference experience.
15. Practical examples of building graduate capital and\ud project co-creation: Towards improved employability
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Namvar, S
- Abstract
The University of Salford is home to a diverse community of learners, with a large percentage of students from BAME, disabled and low socioeconomic backgrounds. The Biomedical Sciences (BMS) programme holds a particularly high proportion of BAME students, many from low-income back grounds and the first in their family to go to university. There is a link between these aforementioned factors, imposter syndrome, progression and employability. Our approach to supporting social mobility is based upon the graduate capital model, which states that employability does not simply relate to a ‘good degree’ but to the many forms of graduate capital. Over the last three years the academic team have developed a range of career mentoring schemes, a careers blackboard site, redeveloped tutorial modules to embed employability and developed an annual careers festival in collaboration with the library, careers services and external partners. These provisions have been complemented by the co-creation of a range of exciting extracurricular projects with students, such as TED-style competitions, a student magazine, general interest reading book clubs and much more. These innovative changes, primarily implemented during the pandemic have brought about a real positive culture change. Some preliminary evidence indicates a positive impact of these activities on graduate outcomes.
16. Effect of an ectonucleotidase inhibitor on anticonvulsant actions of low-frequency electrical stimulation in perforant path rapid kindling in rats
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Maryam Zeraati, Mirnajafi-Zadeh, J., Javan, M., Semnanian, S., and Namvar, S.
17. A riot of rhythms: neuronal and glial circadian oscillators in the mediobasal hypothalamus
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Guilding Clare, Hughes Alun TL, Brown Timothy M, Namvar Sara, and Piggins Hugh D
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background In mammals, the synchronized activity of cell autonomous clocks in the suprachiasmatic nuclei (SCN) enables this structure to function as the master circadian clock, coordinating daily rhythms in physiology and behavior. However, the dominance of this clock has been challenged by the observations that metabolic duress can over-ride SCN controlled rhythms, and that clock genes are expressed in many brain areas, including those implicated in the regulation of appetite and feeding. The recent development of mice in which clock gene/protein activity is reported by bioluminescent constructs (luciferase or luc) now enables us to track molecular oscillations in numerous tissues ex vivo. Consequently we determined both clock activities and responsiveness to metabolic perturbations of cells and tissues within the mediobasal hypothalamus (MBH), a site pivotal for optimal internal homeostatic regulation. Results Here we demonstrate endogenous circadian rhythms of PER2::LUC expression in discrete subdivisions of the arcuate (Arc) and dorsomedial nuclei (DMH). Rhythms resolved to single cells did not maintain long-term synchrony with one-another, leading to a damping of oscillations at both cell and tissue levels. Complementary electrophysiology recordings revealed rhythms in neuronal activity in the Arc and DMH. Further, PER2::LUC rhythms were detected in the ependymal layer of the third ventricle and in the median eminence/pars tuberalis (ME/PT). A high-fat diet had no effect on the molecular oscillations in the MBH, whereas food deprivation resulted in an altered phase in the ME/PT. Conclusion Our results provide the first single cell resolution of endogenous circadian rhythms in clock gene expression in any intact tissue outside the SCN, reveal the cellular basis for tissue level damping in extra-SCN oscillators and demonstrate that an oscillator in the ME/PT is responsive to changes in metabolism.
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- 2009
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18. Scheduled wheel-running stabilizes behavioural rhythms of Vipr2 −/− mice
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Power, A., Hughes, A.T., Namvar, S., and Piggins, H.D.
- Published
- 2006
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19. Effect of different reperfusion strategies on recovery of ventricular function after ST-segment elevation myocardial infarction: A longitudinal single-center study.
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Attar A, Namvar S, Hosseinpour A, Azami P, Shekari A, Jamali L, and Goudarzi N
- Abstract
Background and Aims: Although the clinical benefit of percutaneous coronary intervention (PCI) on cardiovascular outcomes has been widely investigated, the impact of this revascularization strategy compared to other alternatives on the degree of left ventricular function recovery is poorly demonstrated. In this regard, we investigated whether time delays between the presentation of ST-segment elevation myocardial infarction (STEMI) and PCI in reperfusion strategies have different impacts on left ventricular function recovery., Methods: In this single-center study, all the patients who presented with STEMI and a reduced left ventricular ejection fraction (LVEF ≤ 40%) were enrolled. Included patients were subjected to four different treatment groups of primary, rescue (immediate transfer for angioplasty due to failed fibrinolytic therapy), facilitated (fibrinolytic therapy followed by angioplasty within 24 h), and deferred (successful fibrinolytic therapy and PCI after 24 h) PCI based on hospital facilities. Echocardiography was performed for all the patients at the time of hospitalization and 6 months later., Results: A total of 128 patients were included in this study. The LVEF improved by 15.3 ± 6.3%, 11.5 ± 3.61%, 4.0 ± 1.0%, and -1.3 ± 7.0% in primary, rescue, facilitated, and deferred PCI groups, respectively ( p < 0.001). Patients undergoing deferred PCI experienced a significantly lower improvement in LVEF compared with primary and rescue PCI ( p < 0.001)., Conclusion: Primary PCI demonstrated the most promising recovery in left ventricular function following STEMI compared to other alternative strategies. Performing PCI as soon as possible provides better recovery of LVEF., Competing Interests: The authors declare no conflict of interest., (© 2024 The Author(s). Health Science Reports published by Wiley Periodicals LLC.)
- Published
- 2024
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20. Vapor-Phase Synthesis of Electrocatalytic Covalent Organic Frameworks.
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Mohamed SIGP, Namvar S, Zhang T, Shahbazi H, Jiang Z, Rappe AM, Salehi-Khojin A, and Nejati S
- Abstract
The inability to process many covalent organic frameworks (COFs) as thin films plagues their widespread utilization. Herein, a vapor-phase pathway for the bottom-up synthesis of a class of porphyrin-based COFs is presented. This approach allows integrating electrocatalysts made of metal-ion-containing COFs into the electrodes' architectures in a single-step synthesis and deposition. By precisely controlling the metal sites at the atomic level, remarkable electrocatalytic performance is achieved, resulting in unprecedentedly high mass activity values. How the choice of metal atoms, i.e., cobalt and copper, can determine the catalytic activities of POR-COFs is demonstrated. The theoretical data proves that the Cu site is highly active for nitrate conversion to ammonia on the synthesized COFs., (© 2023 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)
- Published
- 2024
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21. Plasma interleukin responses as predictors of outcome stratification in patients after major trauma: a prospective observational two centre study.
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Jones MA, Hanison J, Apreutesei R, Allarakia B, Namvar S, Ramaswamy DS, Horner D, Smyth L, Body R, Columb M, Nirmalan M, and Nirmalan N
- Subjects
- Humans, Biomarkers, Interleukins, Prognosis, Prospective Studies, Interleukin-10, Interleukin-6
- Abstract
Background and Objectives: There is a need to develop objective risk stratification tools to define efficient care pathways for trauma patients. Biomarker-based point of care testing may strengthen existing clinical tools currently available for this purpose. The dysregulation of pro- and anti-inflammatory cytokines in the pathogenesis of organ failure is well recognised. This study was carried out to evaluate whether blood concentrations of IL-6, IL-10, and IL-6:IL-10 ratios in the early stages of the illness are significantly different in patients with worsening organ function., Materials and Methods: In this prospective observational cohort study, plasma concentrations of IL-6 and IL-10 on days 1, 3 and 5 were measured in 91 major trauma patients using a multiplexed cytometric bead array approach. A composite measure of adverse outcome - defined as SOFA ≥ 2 or mortality at 7 days, was the primary outcome. IL-6 and IL-10 concentrations in early samples (days 1, 3 & 5) in patients who developed SOFA ≥ 2 on day 7 were compared against those who did not. Similar composite outcome groups at day 5 and in groups with worsening or improving SOFA scores (ΔSOFA) at days 7 and 5 were undertaken as secondary analyses., Results: Stratification on day 7, 44 (48%) patients showed adverse outcomes. These adverse outcomes associated with significantly greater IL-6 concentrations on days 1 and 5 (Day 1: 47.65 [23.24-78.68] Vs 73.69 [39.93 - 118.07] pg/mL, P = 0.040 and Day 5: 12.85 [5.80-19.51] Vs 28.90 [8.78-74.08] pg/mL; P = 0.0019). Similarly, IL-10 levels were significantly greater in the adverse outcome group on days 3 and 5 (Day 3: 2.54 [1.76-3.19] Vs 3.16 [2.68-4.21] pg/mL; P = 0.044 and Day 5: 2.03 [1.65-2.55] Vs 2.90 [2.00-5.06] pg/mL; P < 0.001). IL-6 and IL-10 concentrations were also significantly elevated in the adverse outcome groups at day 3 and day 5 when stratified on day 5 outcomes. Both IL-6 and IL-6:IL-10 were found to be significantly elevated on days 1 and 3 when stratified based on ΔSOFA at day 5. This significance was lost when stratified on day 7 scores., Conclusions: Early IL-6 and IL-10 concentrations are significantly greater in patients who develop worsening organ functions downstream. These differences may provide an alternate biomarker-based approach to strengthen risk stratification in trauma patients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Jones, Hanison, Apreutesei, Allarakia, Namvar, Ramaswamy, Horner, Smyth, Body, Columb, Nirmalan and Nirmalan.)
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- 2023
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22. Thermodynamics and Kinetics in Anisotropic Growth of One-Dimensional Midentropy Nanoribbons.
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Wang S, Yang T, Kumar K, Namvar S, Kim S, Ahmadiparidari A, Shahbazi H, Singh S, Hemmat Z, Berry V, Cabana J, Khalili-Araghi F, Huang Z, and Salehi-Khojin A
- Abstract
One-dimensional (1D) materials demonstrate anisotropic in-plane physical properties that enable a wide range of functionalities in electronics, photonics, valleytronics, optoelectronics, and catalysis. Here, we undertake an in-depth study of the growth mechanism for equimolar midentropy alloy of (NbTaTi)
0.33 S3 nanoribbons as a model system for 1D transition metal trichalcogenide structures. To understand the thermodynamic and kinetic effects in the growth process, the energetically preferred phases at different synthesis temperatures and times are investigated, and the phase evolution is inspected at a sequence of growth steps. It is uncovered that the dynamics of the growth process occurs at four different stages via preferential incorporation of chemical species at high-surface-energy facets. Also, a sequence of temperature and time dependent nonuniform to uniform phase evolutions has emerged in the composition and structure of (NbTaTi)0.33 S3 which is described based on an anisotropic vapor-solid (V-S) mechanism. Furthermore, direct evidence for the 3D structure of the charge density wave (CDW) phase (width less than 100 nm) is provided by three-dimensional electron diffraction (3DED) in individual nanoribbons at cryogenic temperature, and detailed comparisons are made between the phases obtained before and after CDW transformation. This study provides important fundamental information for the design and synthesis of future 1D alloy structures.- Published
- 2023
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23. Aspergillus fumigatus -Host Interactions Mediating Airway Wall Remodelling in Asthma.
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Namvar S, Labram B, Rowley J, and Herrick S
- Abstract
Asthma is a chronic heterogeneous respiratory condition that is mainly associated with sensitivity to airborne agents such as pollen, dust mite products and fungi. Key pathological features include increased airway inflammation and airway wall remodelling. In particular, goblet cell hyperplasia, combined with excess mucus secretion, impairs clearance of the inhaled foreign material. Furthermore, structural changes such as subepithelial fibrosis and increased smooth muscle hypertrophy collectively contribute to deteriorating airway function and possibility of exacerbations. Current pharmacological therapies focused on airway wall remodelling are limited, and as such, are an area of unmet clinical need. Sensitisation to the fungus, Aspergillus fumigatus, is associated with enhanced asthma severity, bronchiectasis, and hospitalisation. How Aspergillus fumigatus may drive airway structural changes is unclear, although recent evidence points to a central role of the airway epithelium. This review provides an overview of the airway pathology in patients with asthma and fungal sensitisation, summarises proposed airway epithelial cell-fungal interactions and discusses the initiation of a tissue remodelling response. Related findings from in vivo animal models are included given the limited analysis of airway pathology in patients. Lastly, an important role for Aspergillus fumigatus -derived proteases in triggering a cascade of damage-repair events through upregulation of airway epithelial-derived factors is proposed.
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- 2022
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24. Differential Proinflammatory Responses to Aspergillus fumigatus by Airway Epithelial Cells In Vitro Are Protease Dependent.
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Rowley J, Namvar S, Gago S, Labram B, Bowyer P, Richardson MD, and Herrick SE
- Abstract
Aspergillus fumigatus is an important human respiratory mould pathogen. In addition to a barrier function, airway epithelium elicits a robust defence against inhaled A. fumigatus by initiating an immune response. The manner by which A. fumigatus initiates this response and the reasons for the immunological heterogeneity with different isolates are unclear. Both direct fungal cell wall-epithelial cell interaction and secretion of soluble proteases have been proposed as possible mechanisms. Our aim was to determine the contribution of fungal proteases to the induction of epithelial IL-6 and IL-8 in response to different A. fumigatus isolates. Airway epithelial cells were exposed to conidia from a low or high protease-producing strain of A. fumigatus, and IL-6 and IL-8 gene expression and protein production were quantified. The role of proteases in cytokine production was further determined using specific protease inhibitors. The proinflammatory cytokine response correlated with conidia germination and hyphal extension. IL-8 induction was significantly reduced in the presence of matrix metalloprotease or cysteine protease inhibitors. With a high protease-producing strain of A. fumigatus, IL-6 release was metalloprotease dependent. Dectin-1 antagonism also inhibited the production of both cytokines. In conclusion, A. fumigatus -secreted proteases mediate a proinflammatory response by airway epithelial cells in a strain-dependent manner.
- Published
- 2021
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25. Endothelin-1 mediates Aspergillus fumigatus-induced airway inflammation and remodelling.
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Labram B, Namvar S, Hussell T, and Herrick SE
- Subjects
- Animals, Aspergillosis complications, Aspergillosis pathology, Asthma etiology, Asthma pathology, Humans, Male, Mice, Respiratory Mucosa pathology, Airway Remodeling immunology, Aspergillosis immunology, Aspergillus fumigatus immunology, Asthma immunology, Endothelin-1 immunology, Respiratory Mucosa immunology
- Abstract
Background: Asthma is a chronic inflammatory condition of the airways and patients sensitized to airborne fungi such as Aspergillus fumigatus have more severe asthma. Thickening of the bronchial subepithelial layer is a contributing factor to asthma severity for which no current treatment exists. Airway epithelium acts as an initial defence barrier to inhaled spores, orchestrating an inflammatory response and contributing to subepithelial fibrosis., Objective: We aimed to analyse the production of pro-fibrogenic factors by airway epithelium in response to A fumigatus, in order to propose novel anti-fibrotic strategies for fungal-induced asthma., Methods: We assessed the induction of key pro-fibrogenic factors, TGF-β1, TGF-β2, periostin and endothelin-1, by human airway epithelial cells and in mice exposed to A fumigatus spores or secreted fungal factors., Results: Aspergillus fumigatus specifically caused production of endothelin-1 by epithelial cells in vitro but not any of the other pro-fibrogenic factors assessed. A fumigatus also induced endothelin-1 in murine lungs, associated with extensive inflammation and airway remodelling. Using a selective endothelin-1 receptor antagonist, we demonstrated for the first time that endothelin-1 drives many features of airway remodelling and inflammation elicited by A fumigatus., Conclusion: Our findings are consistent with the hypothesis that elevated endothelin-1 levels contribute to subepithelial thickening and highlight this factor as a possible therapeutic target for difficult-to-treat fungal-induced asthma., (© 2019 The Authors. Clinical & Experimental Allergy Published by John Wiley & Sons Ltd.)
- Published
- 2019
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26. Functional molecules in mesothelial-to-mesenchymal transition revealed by transcriptome analyses.
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Namvar S, Woolf AS, Zeef LA, Wilm T, Wilm B, and Herrick SE
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- Animals, Bone Morphogenetic Protein 4 genetics, Bone Morphogenetic Protein 4 metabolism, Cell Movement, Cell Shape, Cells, Cultured, Disease Models, Animal, Epithelial Cells drug effects, Epithelial Cells pathology, Epithelial-Mesenchymal Transition drug effects, Female, Humans, Insulin-Like Growth Factor Binding Protein 4 genetics, Insulin-Like Growth Factor Binding Protein 4 metabolism, Insulin-Like Growth Factor Binding Proteins genetics, Insulin-Like Growth Factor Binding Proteins metabolism, Mice, Inbred C57BL, Peritoneal Fibrosis metabolism, Peritoneal Fibrosis pathology, Peritoneum drug effects, Peritoneum pathology, Rats, Wistar, Transforming Growth Factor beta1 pharmacology, Tumor Suppressor Proteins genetics, Tumor Suppressor Proteins metabolism, Epithelial Cells metabolism, Epithelial-Mesenchymal Transition genetics, Gene Expression Profiling methods, Oligonucleotide Array Sequence Analysis, Peritoneal Fibrosis genetics, Peritoneum metabolism, Transcriptome
- Abstract
Peritoneal fibrosis is a common complication of abdominal and pelvic surgery, and can also be triggered by peritoneal dialysis, resulting in treatment failure. In these settings, fibrosis is driven by activated myofibroblasts that are considered to be partly derived by mesothelial-to-mesenchymal transition (MMT). We hypothesized that, if the molecular signature of MMT could be better defined, these insights could be exploited to block this pathological cellular transition. Rat peritoneal mesothelial cells were purified by the use of an antibody against HBME1, a protein present on mesothelial cell microvilli, and streptavidin nanobead technology. After exposure of sorted cells to a well-known mediator of MMT, transforming growth factor (TGF)-β1, RNA sequencing was undertaken to define the transcriptomes of mesothelial cells before and during early-phase MMT. MMT was associated with dysregulation of transcripts encoding molecules involved in insulin-like growth factor (IGF) and bone morphogenetic protein (BMP) signalling. The application of either recombinant BMP4 or IGF-binding protein 4 (IGFBP4) ameliorated TGF-β1-induced MMT in culture, as judged from the retention of epithelial morphological and molecular phenotypes, and reduced migration. Furthermore, peritoneal tissue from peritoneal dialysis patients showed less prominent immunostaining than control tissue for IGFBP4 and BMP4 on the peritoneal surface. In a mouse model of TGF-β1-induced peritoneal thickening, BMP4 immunostaining on the peritoneal surface was attenuated as compared with healthy controls. Finally, genetic lineage tracing of mesothelial cells was used in mice with peritoneal injury. In this model, administration of BMP4 ameliorated the injury-induced shape change and migration of mesothelial cells. Our findings demonstrate a distinctive MMT signature, and highlight the therapeutic potential for BMP4, and possibly IGFBP4, to reduce MMT. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland., (© 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.)
- Published
- 2018
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27. Cloning and soluble expression of mature α-luffin from Luffa cylindrica in E. coli using SUMO fusion protein.
- Author
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Namvar S, Barkhordari F, Raigani M, Jahandar H, Nematollahi L, and Davami F
- Abstract
α-Lufin, found in Luaf cylindrica seeds, is a type I ribosome inactivating proteins. Cytotoxic effects make it an appropriate candidate for the construction of immunotoxins and conjugates. Because of limited natural resources, recombinant technology is the best approach to achieve large-scale production of plant-based proteins. In the present study, α-lufin protein was expressed in E. coli and the effects of different temperature conditions, SUMO fusion tag, and cultivation strategies on total expression and solubility were investigated. Protein expression was evaluated at different intervals (0, 4, 6, 8, 24 h) postinduction. Our results showed that EnBase had higher eficiency than LB, and maximum solubility and total protein expression were achieved 24 h after induction at 30 °C and 25 °C, respectively. It was shown that SUMO tag is an effective strategy to improve protein solubility.
- Published
- 2018
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28. The antiepileptogenic effect of low-frequency stimulation on perforant path kindling involves changes in regulators of G-protein signaling in rat.
- Author
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Namvar S, Fathollahi Y, Javan M, Zeraati M, Mohammad-Zadeh M, Shojaei A, and Mirnajafi-Zadeh J
- Subjects
- Analysis of Variance, Animals, Antidepressive Agents therapeutic use, Biophysics, Disease Models, Animal, GTP-Binding Proteins metabolism, Gene Expression Regulation drug effects, Gene Expression Regulation physiology, Kindling, Neurologic, Male, Rats, Rats, Wistar, Rolipram therapeutic use, Time Factors, Electric Stimulation methods, Epilepsy therapy, Perforant Pathway physiology, Signal Transduction physiology
- Abstract
G-protein coupled receptors may have a role in mediating the antiepileptogenic effect of low-frequency stimulation (LFS) on kindling acquisition. This effect is accompanied by changes at the intracellular level of cAMP. In the present study, the effect of rolipram as a phosphodiesterase inhibitor on the antiepileptogenic effect of LFS was investigated. Meanwhile, the expression of α
s - and αi -subunit of G proteins and regulators of G-protein signaling (RGS) proteins following LFS application was measured. Male Wistar rats were kindled by perforant path stimulation in a semi-rapid kindling manner (12 stimulations per day) during a period of 6days. Application of LFS (0.1ms pulse duration at 1Hz, 200 pulses, 50-150μA, 5min after termination of daily kindling stimulations) to the perforant path retarded the kindling development and prevented the kindling-induced potentiation and kindling-induced changes in paired pulse indices in the dentate gyrus. Intra-cerebroventricular microinjection of rolipram (0.25μM) partially prevented these LFS effects. Twenty-four hours after the last kindling stimulation, the dentate gyrus was removed and changes in protein expression were measured by Western blotting. There was no significant difference in the expression of α-subunit of Gs and Gi/o proteins in different experimental groups. However, application of LFS during the kindling procedure decreased the expression RGS4 and RGS10 proteins (that reduce the activity of Gi/o ) and prevented the kindling-induced decrease of RGS2 protein (which reduces the Gs activity). Therefore, it can be postulated that the Gi/o protein signaling pathways may be involved in antiepileptogenetic effect of LFS, and this is why decreasing the cAMP metabolism by rolipram attenuates this effect of LFS., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
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29. Dietary fat and corticosterone levels are contributing factors to meal anticipation.
- Author
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Namvar S, Gyte A, Denn M, Leighton B, and Piggins HD
- Subjects
- Adaptation, Physiological, Animals, Calorimetry, Indirect, Dietary Fats blood, Energy Intake, Energy Metabolism, Fatty Acids, Nonesterified administration & dosage, Fatty Acids, Nonesterified blood, Hormone Antagonists pharmacology, Hypothalamus drug effects, Male, Mifepristone pharmacology, Motor Activity, Proto-Oncogene Proteins c-fos metabolism, Rats, Wistar, Time Factors, Anticipation, Psychological drug effects, Appetite Regulation drug effects, Circadian Rhythm drug effects, Diet, High-Fat, Dietary Fats administration & dosage, Feeding Behavior drug effects, Hydrocortisone blood, Hypothalamus metabolism
- Abstract
Daily restricted access to food leads to the development of food anticipatory activity and metabolism, which depends upon an as yet unidentified food-entrainable oscillator(s). A premeal anticipatory peak in circulating hormones, including corticosterone is also elicited by daily restricted feeding. High-fat feeding is associated with elevated levels of corticosterone with disrupted circadian rhythms and a failure to develop robust meal anticipation. It is not clear whether the disrupted corticosterone rhythm, resulting from high-fat feeding contributes to attenuated meal anticipation in high-fat fed rats. Our aim was to better characterize meal anticipation in rats fed a low- or high-fat diet, and to better understand the role of corticosterone in this process. To this end, we utilized behavioral observations, hypothalamic c-Fos expression, and indirect calorimetry to assess meal entrainment. We also used the glucocorticoid receptor antagonist, RU486, to dissect out the role of corticosterone in meal anticipation in rats given daily access to a meal with different fat content. Restricted access to a low-fat diet led to robust meal anticipation, as well as entrainment of hypothalamic c-Fos expression, metabolism, and circulating corticosterone. These measures were significantly attenuated in response to a high-fat diet, and animals on this diet exhibited a postanticipatory rise in corticosterone. Interestingly, antagonism of glucocorticoid activity using RU486 attenuated meal anticipation in low-fat fed rats, but promoted meal anticipation in high-fat-fed rats. These findings suggest an important role for corticosterone in the regulation of meal anticipation in a manner dependent upon dietary fat content., (Copyright © 2016 the American Physiological Society.)
- Published
- 2016
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30. The role of piriform cortex adenosine A1 receptors on hippocampal kindling.
- Author
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Namvar S, Mirnajafi-Zadeh J, Fathollahi Y, and Zeraati M
- Subjects
- Adenosine analogs & derivatives, Adenosine pharmacology, Analysis of Variance, Animals, Disease Models, Animal, Drug Interactions, Electric Stimulation adverse effects, Electroencephalography, Entorhinal Cortex drug effects, Kindling, Neurologic radiation effects, Male, Microinjections, Rats, Rats, Sprague-Dawley, Seizures drug therapy, Seizures etiology, Time Factors, Xanthines pharmacology, Entorhinal Cortex metabolism, Hippocampus physiopathology, Kindling, Neurologic physiology, Receptor, Adenosine A1 physiology, Seizures pathology
- Abstract
Introduction: The hippocampus and piriform cortex have a critical role in seizure propagation. In this study, the role of adenosine A1 receptors of piriform cortex on CA1 hippocampal kindled seizures was studied in rats., Methods: Animals were implanted with a tripolar electrode in the right hippocampal CA1 region and two guide cannulae in the left and right piriform cortex. They were kindled by daily electrical stimulation of hippocampus. In fully kindled rats, N6- cyclohexyladenosine (CHA; a selective adenosine A1 receptors agonist) and 1,3-dimethyl-8-cyclopenthylxanthine (CPT a selective adenosine A1 receptor antagonist) were microinfused into the piriform cortex. The animals were stimulated at 5, 15 and 90 minutes (min) after drug injection., Results: Obtained data showed that CHA (10 and 100 microM) reduced afterdischarge duration, stage 5 seizure duration, and total seizure duration at 5 and 15 min after drug injection. There was no significant change in latency to stage 4 seizure. CPT at concentration of 20 microM increased afterdischarge duration, stage 5 seizure duration, and total seizure duration and decreased latency to stage 4 seizure at 5 and 15 min post injection. Pretreatment of rats with CPT (10 microM), 5 min before CHA (100 microM), reduced the effect of CHA on seizure parameters., Conclusion: These results suggested that activity of adenosine A1 receptors in the piriform cortex has an anticonvulsant effect on kindled seizures resulting from electrical stimulation of the CA1 region of the hippocampus.
- Published
- 2008
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31. Adenosine A1 and A2A receptors of hippocampal CA1 region have opposite effects on piriform cortex kindled seizures in rats.
- Author
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Zeraati M, Mirnajafi-Zadeh J, Fathollahi Y, Namvar S, and Rezvani ME
- Subjects
- Adenosine analogs & derivatives, Adenosine pharmacology, Adenosine A1 Receptor Agonists, Adenosine A1 Receptor Antagonists, Adenosine A2 Receptor Agonists, Adenosine A2 Receptor Antagonists, Animals, Cerebral Cortex physiopathology, Electric Stimulation, Hippocampus physiopathology, Kindling, Neurologic, Male, Phenethylamines pharmacology, Rats, Rats, Sprague-Dawley, Receptors, Purinergic P2, Triazines pharmacology, Triazoles pharmacology, Xanthines pharmacology, Hippocampus drug effects, Receptor, Adenosine A1 physiology, Receptor, Adenosine A2A physiology, Seizures physiopathology
- Abstract
In this study the role of adenosine A1 and A2A receptors of the hippocampal CA1 region on piriform cortex-kindled seizures was investigated in rats. Animals were kindled by daily electrical stimulation of piriform cortex. In fully kindled rats, N6-cyclohexyladenosine (CHA; a selective A1 receptor agonist), 1,3-dimethyl-8-cyclopenthylxanthine (CPT; a selective A1 receptor antagonist), CGS21680 hydrochloride (CGS, a selective A2A receptor agonist) and, ZM241385 (ZM, a selective A2A receptor antagonist) were microinfused bilaterally into the hippocampal CA1 region. Rats were stimulated and seizure parameters were measured. Obtained results showed that microinjection of CHA (10 and 100 microM) decreased the afterdischarge duration (ADD), stage 5 seizure duration (S5D) and seizure duration (SD), and significantly increased the latency to stage 4 (S4L). Intra-hippocampal CPT increased ADD at the dose of 20 microM. Pretreatment of rats with CPT (10 microM) before CHA (10 microM), significantly reduced the effect of CHA on seizure parameters. On the other hand, microinjection of CGS (200 and 500 microM) increased ADD, but of ZM had no effect on seizure parameters. Pretreatment of rats with ZM (50 microM) before CGS (500 microM), significantly reduced the effect of CGS on seizure parameters. The results suggest that the facilitatory role of the hippocampal CA1 region in relaying or spreading of piriform cortex kindled seizures is decreased by the activation of adenosine A1 receptors and increased by A2A receptors.
- Published
- 2006
- Full Text
- View/download PDF
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