86 research outputs found

    FGF-2, TGFβ-1, PDGF-A and respective receptors expression in pleomorphic adenoma myoepithelial cells: an in vivo and in vitro study

    Get PDF
    Myoepithelial cells have an important role in salivary gland tumor development, contributing to a low grade of aggressiveness of these tumors. Normal myoepithelial cells are known by their suppressor function presenting increased expression of extracellular matrix genes and protease inhibitors. The importance of stromal cells and growth factors during tumor initiation and progression has been highlighted by recent literature. Many tumors result from the alteration of paracrine growth factors pathways. Growth factors mediate a wide variety of biological processes such as development, tissue repair and tumorigenesis, and also contribute to cellular proliferation and transformation in neoplastic cells. OBJECTIVES: This study evaluated the expression of fibroblast growth factor-2 (FGF-2), transforming growth factor β-1 (TGFβ-1), platelet-derived growth factor-A (PDGF-A) and their respective receptors (FGFR-1, FGFR-2, TGFβR-II and PDGFR-α) in myoepithelial cells from pleomorphic adenomas (PA) by in vivo and in vitro experiments. MATERIAL AND METHODS: Serial sections were obtained from paraffin-embedded PA samples obtained from the school's files. Myoepithelial cells were obtained from explants of PA tumors provided by surgery from different donors. Immunohistochemistry, cell culture and immunofluorescence assays were used to evaluate growth factor expression. RESULTS: The present findings demonstrated that myoepithelial cells from PA were mainly positive to FGF-2 and FGFR-1 by immunohistochemistry and immunofluorescence. PDGF-A and PDGFR-α had moderate expression by immunohistochemistry and presented punctated deposits throughout cytoplasm of myoepithelial cells. FGFR-2, TGFβ-1 and TGFβR-II were negative in all samples. CONCLUSIONS: These data suggested that FGF-2 compared to the other studied growth factors has an important role in PA benign myoepithelial cells, probably contributing to proliferation of these cells through the FGFR-1

    Selective area epitaxy of ultra-high density InGaN quantum dots by diblock copolymer lithography

    Get PDF
    Highly uniform InGaN-based quantum dots (QDs) grown on a nanopatterned dielectric layer defined by self-assembled diblock copolymer were performed by metal-organic chemical vapor deposition. The cylindrical-shaped nanopatterns were created on SiNx layers deposited on a GaN template, which provided the nanopatterning for the epitaxy of ultra-high density QD with uniform size and distribution. Scanning electron microscopy and atomic force microscopy measurements were conducted to investigate the QDs morphology. The InGaN/GaN QDs with density up to 8 × 1010 cm-2 are realized, which represents ultra-high dot density for highly uniform and well-controlled, nitride-based QDs, with QD diameter of approximately 22-25 nm. The photoluminescence (PL) studies indicated the importance of NH3 annealing and GaN spacer layer growth for improving the PL intensity of the SiNx-treated GaN surface, to achieve high optical-quality QDs applicable for photonics devices

    Development and Validation of a New Method to Measure Walking Speed in Free-Living Environments Using the Actibelt® Platform

    Get PDF
    Walking speed is a fundamental indicator for human well-being. In a clinical setting, walking speed is typically measured by means of walking tests using different protocols. However, walking speed obtained in this way is unlikely to be representative of the conditions in a free-living environment. Recently, mobile accelerometry has opened up the possibility to extract walking speed from long-time observations in free-living individuals, but the validity of these measurements needs to be determined. In this investigation, we have developed algorithms for walking speed prediction based on 3D accelerometry data (actibelt®) and created a framework using a standardized data set with gold standard annotations to facilitate the validation and comparison of these algorithms. For this purpose 17 healthy subjects operated a newly developed mobile gold standard while walking/running on an indoor track. Subsequently, the validity of 12 candidate algorithms for walking speed prediction ranging from well-known simple approaches like combining step length with frequency to more sophisticated algorithms such as linear and non-linear models was assessed using statistical measures. As a result, a novel algorithm employing support vector regression was found to perform best with a concordance correlation coefficient of 0.93 (95%CI 0.92–0.94) and a coverage probability CP1 of 0.46 (95%CI 0.12–0.70) for a deviation of 0.1 m/s (CP2 0.78, CP3 0.94) when compared to the mobile gold standard while walking indoors. A smaller outdoor experiment confirmed those results with even better coverage probability. We conclude that walking speed thus obtained has the potential to help establish walking speed in free-living environments as a patient-oriented outcome measure

    Variation in Uteroglobin-Related Protein 1 (UGRP1) gene is associated with Allergic Rhinitis in Singapore Chinese

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Uteroglobin-Related Protein 1 (<it>UGRP1</it>) is a secretoglobulin protein which has been suggested to play a role in lung inflammation and allergic diseases. UGRP1 has also been shown to be an important pneumoprotein, with diagnostic potential as a biomarker of lung damage. Previous genetic studies evaluating the association between variations on <it>UGRP1 </it>and allergic phenotypes have yielded mixed results. The aim of this present study was to identify genetic polymorphisms in <it>UGRP1 </it>and investigate if they were associated with asthma and allergic rhinitis in the Singapore Chinese population.</p> <p>Methods</p> <p>Resequencing of the <it>UGRP1 </it>gene was conducted on 40 randomly selected individuals from Singapore of ethnic Chinese origin. The polymorphisms identified were then tagged and genotyped in a population of 1893 Singapore Chinese individuals. Genetic associations were evaluated in this population comparing 795 individuals with allergic rhinitis, 718 with asthma (of which 337 had both asthma and allergic rhinitis) and 717 healthy controls with no history of allergy or allergic diseases.</p> <p>Results</p> <p>By resequencing the <it>UGRP1 </it>gene within our population, we identified 11 novel and 16 known single nucleotide polymorphisms (SNPs). TagSNPs were then genotyped, revealing a significant association between rs7726552 and allergic rhinitis (Odds Ratio: 0.81, 95% Confidence Interval: 0.66-0.98, P = 0.039). This association remained statistically significant when it was analyzed genotypically or when stratified according to haplotypes. When variations on <it>UGRP1 </it>were evaluated against asthma, no association was observed.</p> <p>Conclusion</p> <p>This study documents the association between polymorphisms in <it>UGRP1 </it>and allergic rhinitis, suggesting a potential role in its pathogenesis.</p

    AQP5 enriches for stem cells and cancer origins in the distal stomach

    Get PDF
    LGR5 marks resident adult epithelial stem cells at the gland base in the mouse pyloric stomach1, but the identity of the equivalent human stem cell population remains unknown owing to a lack of surface markers that facilitate its prospective isolation and validation. In mouse models of intestinal cancer, LGR5+ intestinal stem cells are major sources of cancer following hyperactivation of the WNT pathway2. However, the contribution of pyloric LGR5+ stem cells to gastric cancer following dysregulation of the WNT pathway—a frequent event in gastric cancer in humans3—is unknown. Here we use comparative profiling of LGR5+ stem cell populations along the mouse gastrointestinal tract to identify, and then functionally validate, the membrane protein AQP5 as a marker that enriches for mouse and human adult pyloric stem cells. We show that stem cells within the AQP5+ compartment are a source of WNT-driven, invasive gastric cancer in vivo, using newly generated Aqp5-creERT2 mouse models. Additionally, tumour-resident AQP5+ cells can selectively initiate organoid growth in vitro, which indicates that this population contains potential cancer stem cells. In humans, AQP5 is frequently expressed in primary intestinal and diffuse subtypes of gastric cancer (and in metastases of these subtypes), and often displays altered cellular localization compared with healthy tissue. These newly identified markers and mouse models will be an invaluable resource for deciphering the early formation of gastric cancer, and for isolating and characterizing human-stomach stem cells as a prerequisite for harnessing the regenerative-medicine potential of these cells in the clinic

    International entrepreneurship in SMEs: a study of influencing factors in the textile industry

    Full text link
    The final publication is available at Springer via http://dx.doi.org/10.1007/s11365-012-0242-3International entrepreneurship is an incipient research area with a rapidly increasing body of knowledge and contributions. An important part of this literature has focused on the analysis of the contributing factors to IE development. From these studies, this work attempts to analyse and validate through an integrative model the effect on this construct in SME of some of the main factors proposed by the literature such as Skills and Competences, Attitude and Proactiveness, Creativity and Innovation, Networking, Employees and Activity. To proceed with this aim, we conducted an empirical research focused on 174 textile SME in Spain. The results obtained confirm a positive relationship between the studied factors and the IE development. In consequence, this work agrees with previous literature that point out the need to use multi-theoretical perspectives, combining multiple factors.Gil Pechuán, I.; Expósito Langa, M.; Tomas Miquel, JV. (2013). International entrepreneurship in SMEs: a study of influencing factors in the textile industry. International Entrepreneurship and Management Journal. 9(1):45-57. doi:10.1007/s11365-012-0242-3S455791Akgün, A., Keskin, H., & Byrne, J. (2012). Organizational emotional memory. Management Decision, 50(1), 95–114.Andersén, J. (2011). Strategic resources and firm performance. Management Decision, 49(1), 87–98.Anderson, A. R., Dodd, S. D., & Jack, S. L. (2012). Entrepreneurship as connecting: some implications for theorising and practice. Management Decision, 50(5), 958–971.Appelbaum, S. H., Roy, M., & Gilliland, T. (2011). Globalization of performance appraisals: theory and applications. Management Decision, 49(4), 570–585.Arribas, I., Hernández, P., Urbano, A., & Vila, J. E. (2012). Are social and entrepreneurial attitudes compatible? A behavioral and self-perceptional analysis. Management Decision, 50(10), 1739–1757.Audretsch, D. (2012). Entrepreneurship research. Management Decision, 50(5), 755–764.Autio, E., Sapienza, H. J., & Almeida, J. G. (2000). Effects of age at entry, knowledge intensity, and imitability on international growth. Academy of Management Journal, 43, 909–924.Bannon, L. (1998). Mattel plans to double sales abroad. Wall Street Journal, February 11, (A3 and A8).Battistella, C., Biotto, G., & De Toni, A. (2012). From design driven innovation to meaning strategy. Management Decision, 50(4), 718–743.Bell, J., McNaughton, J., Young, R., & Crick, D. (2003). Towards an integrative model of small firm internationalization. Journal of International Entrepreneurship, 1, 339–362.Bonzo, P., Valadares de Oliveira, P., & McCormarck. (2012). Planning, capabilities, and performance: an integrated value approach. Management Decision, 50(6), 1001–1021.Bossak, J., & Nagashima, S. (1997). Corporate strategies for a borderless world: sharpening your competitive edge. Tokyo: Asian Productivity Organization.Cambra-Fierro, J., Florin, J., Perez, L., & Whitelock, J. (2011). Inter-firm market orientation as antecedent of knowledge transfer, innovation and value creation in networks. Management Decision, 49(3), 444–467.Cantarello, S., Nosella, A., Petroni, G., & Venturini, K. (2011). External technology sourcing: evidence from design-driven innovation. Management Decision, 49(6), 962–983.Chang, Y. Y., Hughes, M., & Hotho, S. (2011). Internal and external antecedents of SMEs’ innovation ambidexterity outcomes. Management Decision, 49(10), 1658–1676.Chaston, I., & Scott, G. J. (2012). Entrepreneurship and open innovation in an emerging economy. Management Decision, 50(7), 1161–1177.Coviello, N. E., & Jones, M. V. (2004). Methodological issues in international entrepreneurship research. Journal of Business Venturing, 19, 485–508.Coviello, N. E., & McAuley, A. (1999). Internationalization and the smaller firm: a review of contemporary empirical research. Management International Review, 39, 223–256.Covin, J., & Slevin, D. (1989). Strategic management of small firms in hostile and benign environments. Strategic Management Journal, 10(1), 75–87.Covin, J., & Slevin, D. (1991). A conceptual model of entrepreneurship as firm behavior. Entrepreneurship Theory and Practice, 16, 7–25.Davis, D., Morris, M., & Allen, J. (1991). Perceived environmental turbulence and its effect on selected entrepreneurship, marketing, and organizational characteristics in industrial firms. Journal of the Academy of Marketing Science, 19(1), 43–51.Dean, C. C., Thibodeaux, M. S., Beyerlein, M., Ebrahimi, B., & Molina, D. (1993). Corporate entrepreneurship and competitive aggressiveness. A comparison of U.S. firms operating in eastern Europe and the Commonwealth of Independent States with U.S. firms in other high-risk environments. Advances in International Comparative Management, 8, 31–54.Dess, G. G., & Robinson, R. B. (1984). Measuring organizational performance in the absence of objective measures: the case of privately held firms and conglomerate business units. Strategic Management Journal, 5, 265–273.Dess, G. G., Lumpkin, G. T., & Covin, J. G. (1997). Entrepreneurial strategy making and firm performance: tests of contingency and configurational models. Strategic Management Journal, 18, 677–695.Díaz-Casero, J. C., Díaz-Aunión, A., Sánchez-Escobedo, M. C., Coduras-Martinez, A., & Hernández-Mogollón, R. (2012). Economic freedom and entrepreneurial activity. Management Decision, 50(9), 1686–1711.Dimitratos, P., & Plakoyiannaki, E. (2003). Theoretical foundations of an international entrepreneurial culture. Journal of International Entrepreneurship, 1, 187–215.Dubini, P., & Aldrich, H. (1991). Personal and extended networks are central to the entrepreneurial process. Journal of Business Venturing, 6, 305–313.Felício, J. A., Rodrigues, R., & Caldeirinha, V. R. (2012). The effect of intrapreneurship on corporate performance. Management Decision, 50(10), 1717–1738.Goktan, A. B., & Miles, G. (2011). Innovation speed and radicalness: are they inversely related? Management Decision, 49(4), 533–547.Gómez-Haro, S., Aragón-Correa, J. A., & Cordón-Pozo, E. (2011). Differentiating the effects of the institutional environment on corporate entrepreneurship. Management Decision, 49(10), 1677–1693.Hitt, M. A., Ireland, R. D., Camp, S. M., & Sexton, L. D. (2001). Strategic entrepreneurship: entrepreneurial strategies for wealth creation [Special Issue]. Strategic Management Journal, 22(6), 479–492.Hotho, S., & Champion, K. (2011). Small businesses in the new creative industries: innovation as a people management challenge. Management Decision, 49(1), 29–54.Hu, Y.-S. (1995). The international transferability of competitive advantage. California Management Review, 37(4), 73–88.Huarng, K. H., & Yu, T. H. K. (2011). Entrepreneurship, process innovation and value creation by a non-profit SME. Management Decision, 49(2), 284–296.Jones, M. V. (1999). The internationalization of small UK high technology based firms. Journal of International Marketing, 7, 15–41.Jones, M. V., & Coviello, N. E. (2005). Internationalization: conceptualising and entrepreneurial process of behaviour in time. Journal of International Business Studies, 36(3):284–303.Khandwalla, P. (1977). The design of organizations. New York: Harcourt Brace Jovanovich.Knight, G. A., & Cavusgil, S. T. (2004). Innovation, organization capabilities, and the born-global firm. Journal of International Business Studies, 35, 124–141.Kropp, F., Lindsay, N. J., & Shoham, A. (2006). Entrepreneurial, market, and learning orientations and international entrepreneurial business venture performance in South African firms. International Marketing Review, 23(5), 504–523.Liebeskind, J. P. (1996). Knowledge, strategy, and the theory of the firm. Strategic Management Journal, 17, 93–107.Lumpkin, G. T., & Dess, G. G. (1996). Clarifying the entrepreneurial construct and linking it to performance. Academy of Management Review, 21, 135–172.McDougall, P. P., & Oviatt, B. M. (2000). International entrepreneurship: the intersection of two research paths. Academy of Management Journal, 43, 902–908.McDougall, P. P., Shane, S., & Oviatt, B. M. (1994). Explaining the formation of international new ventures: the limits of theories from international business research. Journal of Business Venturing, 9, 469–487.McGrath, R. G., MacMillan, I. C., & Venkataraman, S. (1995). Global dimensions of new competencies. In S. Birley & I. C. MacMillan (Eds.), International entrepreneurship. New York: Routledge.McNaughton, R. B. (2001). The export mode decision-making process in small knowledge- intensive firms. Market Intelligence and Planning, 19, 12–20.McNaughton, R. B. (2003). The number of export markets that a firm serves: process models versus the born-global phenomenon. Journal of International Entrepreneurship, 1, 297–311.Miles, R. E., & Snow, C. C. (1978). Organizational strategy, structure and process. New York: McGraw-Hill.Miller, D. (1983). The correlates of entrepreneurship in three types of firms. Management Science, 29(7), 770–791.Miller, D., & Friesen, P. (1984). Organizations: a quantum view. Englewood Cliffs: Prentice-Hall.Morrow, J. F. (1988). International entrepreneurship: a new growth opportunity. New Management, 3, 59–61.Murphy, G. B., Trailer, J. W., & Hill, R. C. (1996). Measuring performance in entrepreneurship research. Journal of Business Research, 36, 15–23.Naman, J. L., & Slevin, D. P. (1993). Entrepreneurship and the concept of fit: a model and empirical tests. Strategic Management Journal, 14, 137–153.Naranjo-Valencia, J. C., Jiménez-Jiménez, D., & Sanz-Valle, R. (2011). Innovation or imitation? The role of organizational culture. Management Decision, 49(1), 55–72.Oviatt, B. M., & McDougall, P. P. (1994). Toward a theory of international new ventures. Journal of International Business Studies, 25(1), 45–64.Oviatt, B. M., & McDougall, P. P. (1999). A framework for understanding accelerated international entrepreneurship. In R. Wright (Ed.), Research in global strategic management (pp. 23–40). Stamford: JAI Press.Oviatt, B. M., & McDougall, P. P. (2005). Defining international entrepreneurship and modeling the speed of internalization. Entrepreneurship Theory & Practice, 29(5), 537–554.Peiris, I.K., Akoorie, M.E.M., & Sinha, P.N. (2012). International entrepreneurship: A critical analysis of studies in the past two decades and future directions for research. Journal of International Entrepreneurship. Article in press.Pinchot, G., III. (1985). Intrapreneuring: why you don’t have to leave the corporation to become entrepreneur. New York: Harper and Row Publishers.Porter, M. (1990). The competitive advantage of nations. London: Collier-Macmillan.Renko, M., Shrader, R. C., & Simon, M. (2012). Perception of entrepreneurial opportunity: a general framework. Management Decision, 50(7), 1233–1251.Sandulli, F. D., Fernandez-Menendez, J., Rodriguez-Duarte, A., & Lopez-Sanchez, J. I. (2012). Testing the Schumpeterian hypotheses on an open innovation framework. Management Decision, 50(7), 1222–1232.Santos, F. J., Romero, I., & Fernández-Serrano, J. (2012). SMEs and entrepreneurial quality from a macroeconomic perspective. Management Decision, 50(8), 1382–1395.Shama, A. (1995). Entry strategies of U.S. firms to the former Soviet Bloc and Eastern Europe. California Management Review, 37(3), 90–109.Simon, H. (1996). Hidden champions: lessons from 500 of the world’s best unknown companies. Boston: Harvard Business School Press.Singh, S., Darwish, T. K., Costa, A. C., & Anderson, N. (2012). Measuring HRM and organisational performance: concepts, issues, and framework. Management Decision, 50(4), 651–667.Smart, T. (1996). GE’s Welch: ‘Fighting like hell to be No. 1’. Business Week, July 8, 48.Snow, C., & Hrebiniak, L. (1980). Strategy, distinctive competence, and organizational performance. Administrative Science Quarterly, 25, 317–336.Stevenson, H. H., & Jarillo, J. C. (1990). A paradigm of entrepreneurship: entrepreneurial management. Strategic Management Journal, 11, 17–27.Styles, C., & Seymour, R. G. (2006). Opportunities for marketing researchers in international entrepreneurship. International Marketing Review, 23(2), 126–145.Turner, R., Ledwith, A., & Kelly, J. (2012). Project management in small to medium-sized enterprises: tailoring the practices to the size of company. Management Decision, 50(5), 942–957.Venkatraman, N., & Ramanujam, V. (1986). Measurement of business performance in strategy research: a comparison of approaches. Academy of Management Review, 11, 801–814.Vlasic, B. (1998). The little car that could carry Chrysler overseas. Business Week, 19, 39.Welbourne, T. M., Neck, H., & Meyer, G. D. (2012). The entrepreneurial growth ceiling: using people and innovation to mitigate risk and break through the growth ceiling in initial public offerings. Management Decision, 50(5), 778–796.Williamson, P. J. (1997). Asia’s new competitive game. Harvard Business Review, 75(5), 55–67.Yeoh, P. L. (2004). International learning: antecedents and performance implications among newly internationalizing companies in an exporting context. International Marketing Review, 21(4/5), 511–535.Zahra, S. A. (1991). Predictors and financial outcomes of corporate entrepreneurship. An exploratory study. Journal of Business Venturing, 6(4), 259–285.Zahra, S. A. (1993a). Environment, corporate entrepreneurship and financial performance. A taxonomic approach. Journal of Business Venturing, 8(4), 319–340.Zahra, S. A. (1993b). A conceptual model of entrepreneurship as firm behavior: a critique and extensión. Entrepreneurship Theory and Practice, 17(4), 5–21.Zahra, S. A., & George, G. (2002). International entrepreneurship: the current status of the field and future agenda. In M. A. Hitt, R. D. Ireland, S. M. Camp, & D. L. Sexton (Eds.), Strategic entrepreneurship: creating a new mindset. Oxford: Blackwell Publishers.Zahra, S. A., Jennings, D. F., & Kuratko, D. F. (1999). The antecedents and consequences of firm-level entrepreneurship: the state of the field. Entrepreneurship Theory and Practice, 24(2), 45–63.Zhou, L. (2007). The effects of entrepreneurial proclivity and foreign market knowledge on early internationalization. Journal of World Business, 42(3), 281–293

    NALP3 inflammasome upregulation and CASP1 cleavage of the glucocorticoid receptor cause glucocorticoid resistance in leukemia cells

    Get PDF
    Glucocorticoids are universally used in the treatment of acute lymphoblastic leukemia (ALL), and resistance to glucocorticoids in leukemia cells confers poor prognosis. To elucidate mechanisms of glucocorticoid resistance, we determined the prednisolone sensitivity of primary leukemia cells from 444 patients newly diagnosed with ALL and found significantly higher expression of CASP1 (encoding caspase 1) and its activator NLRP3 in glucocorticoid-resistant leukemia cells, resulting from significantly lower somatic methylation of the CASP1 and NLRP3 promoters. Overexpression of CASP1 resulted in cleavage of the glucocorticoid receptor, diminished the glucocorticoid-induced transcriptional response and increased glucocorticoid resistance. Knockdown or inhibition of CASP1 significantly increased glucocorticoid receptor levels and mitigated glucocorticoid resistance in CASP1-overexpressing ALL. Our findings establish a new mechanism by which the NLRP3-CASP1 inflammasome modulates cellular levels of the glucocorticoid receptor and diminishes cell sensitivity to glucocorticoids. The broad impact on the glucocorticoid transcriptional response suggests that this mechanism could also modify glucocorticoid effects in other diseases

    Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

    Get PDF
    Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

    Get PDF
    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

    A genome-scale integrated approach aids in genetic dissection of complex flowering time trait in chickpea

    Get PDF
    A combinatorial approach of candidate gene-based association analysis and genome-wide association study (GWAS) integrated with QTL mapping, differential gene expression profiling and molecular haplotyping was deployed in the present study for quantitative dissection of complex flowering time trait in chickpea. Candidate gene-based association mapping in a flowering time association panel (92 diverse desi and kabuli accessions) was performed by employing the genotyping information of 5724 SNPs discovered from 82 known flowering chickpea gene orthologs of Arabidopsis and legumes as well as 832 gene-encoding transcripts that are differentially expressed during flower development in chickpea. GWAS using both genome-wide GBS- and candidate gene-based genotyping data of 30,129 SNPs in a structured population of 92 sequenced accessions (with 200–250 kb LD decay) detected eight maximum effect genomic SNP loci (genes) associated (34 % combined PVE) with flowering time. Six flowering time-associated major genomic loci harbouring five robust QTLs mapped on a high-resolution intra-specific genetic linkage map were validated (11.6–27.3 % PVE at 5.4–11.7 LOD) further by traditional QTL mapping. The flower-specific expression, including differential up- and down-regulation (>three folds) of eight flowering time-associated genes (including six genes validated by QTL mapping) especially in early flowering than late flowering contrasting chickpea accessions/mapping individuals during flower development was evident. The gene haplotype-based LD mapping discovered diverse novel natural allelic variants and haplotypes in eight genes with high trait association potential (41 % combined PVE) for flowering time differentiation in cultivated and wild chickpea. Taken together, eight potential known/candidate flowering time-regulating genes [efl1 (early flowering 1), FLD (Flowering locus D), GI (GIGANTEA), Myb (Myeloblastosis), SFH3 (SEC14-like 3), bZIP (basic-leucine zipper), bHLH (basic helix-loop-helix) and SBP (SQUAMOSA promoter binding protein)], including novel markers, QTLs, alleles and haplotypes delineated by aforesaid genome-wide integrated approach have potential for marker-assisted genetic improvement and unravelling the domestication pattern of flowering time in chickpea
    corecore