Now showing items 1-20 of 8533

    • Geophysical investigation of the neolithic Calanais landscape

      Bates, C.R.; Bates, M.; Gaffney, Christopher F.; Gaffney, Vincent L.; Raub, T.D. (2019-12)
      The northern and western isles of Scotland have proved fertile ground for archaeological investigation over the last 100 years. However, the nature of the landscape with its rugged coastlines and irregular topography, together with rapid peat growth rates, make for challenging surveying. Commonly, an archaeological monument or series of monuments is identified but little is known about the surrounding areas and, in particular, the palaeo-landscapes within which the monuments are located. This situation is exemplified by the standing stones of Calanais in Lewis. Here, surrounding peat bogs have buried a significant portion of the landscape around which the stones were first erected. This project identifies remote sensing geophysical techniques that are effective in mapping the buried (lost) landscape and thus aid better contextualisation of the stone monuments within it. Further, the project demonstrates the most appropriate techniques for prospecting across these buried landscapes for as yet unidentified stone features associated with the lives of the people who constructed the monuments.
    • Autologous cell therapy for aged human skin: A randomized, placebo-controlled, phase-I study

      Grether-Beck, S.; Marini, A.; Jaenicke, T.; Goessens-Rück, P.; McElwee, Kevin J.; Hoffman, R.; Krutmann, J. (2019)
      Introduction: Skin ageing involves senescent fibroblast accumulation, disturbance in extracellular matrix (ECM) homeostasis, and decreased collagen synthesis. Objective: to assess a cell therapy product for aged skin (RCS-01; verum) consisting of ~25 × 106 cultured, autologous cells derived from anagen hair follicle non-bulbar dermal sheath (NBDS). Methods: For each subject in the verum group, 4 areas of buttock skin were injected intradermally 1 or 3 times at monthly intervals with RCS-01, cryomedium, or needle penetration without injection; in the placebo group RCS-01 was replaced by cryomedium. The primary endpoint was assessment of local adverse event profiles. As secondary endpoints, expression of genes related to ECM homeostasis was assessed in biopsies from randomly selected volunteers in the RCS-01 group taken 4 weeks after the last injection. ­Results: Injections were well tolerated with no severe adverse events reported 1 year after the first injection. When compared with placebo-treated skin, a single treatment with RCS-01 resulted in a significant upregulation of TGFβ1, CTGF, COL1A1, COL1A2, COL3A1, and lumican mRNA expression. Limitations: The cohort size was insufficient for dose ­ranging evaluation and subgroup analyses of efficacy. Conclusions: RCS-01 therapy is well tolerated and associated with a gene expression response consistent with an improvement of ECM homeostasis.
    • Increased expression of TLR7 and TLR9 in alopecia areata

      Kang, H.; Wu, W-Y.; Yu, M.; Shapiro, J.; McElwee, Kevin J. (2020)
      Alopecia areata (AA) is thought to be an autoimmune process. In other autoimmune diseases, the innate immune system and Toll‐like receptors (TLRs) can play a significant role. Expression of TLR7, TLR9 and associated inducible genes was evaluated by quantitative PCR in peripheral blood mononuclear cells (PBMCs) from 10 healthy individuals and 19 AA patients, categorized according to disease duration, activity and hair loss extent. Microdissected scalp biopsies from five patients and four controls were also assessed by quantitative PCR and immunohistology. TLR9 was significantly upregulated 2.37 fold in AA PBMCs. Notably, TLR9 was most significantly upregulated in patients with active AA, as shown by a positive hair pull test, compared to stable AA patients. In hair follicle bulbs from AA patients, IFNG and TLR7 exhibited statistically significant 3.85 and 2.70 fold increases in mRNA, respectively. Immunohistology revealed TLR7 present in lesional follicles, while TLR9 positive cells were primarily observed peri‐bulbar to AA affected hair follicles. The increased expression of TLR7 and TLR9 suggest components of the innate immune system may be active in AA pathogenesis.
    • Pedagogical violence

      Matusov, E.; Sullivan, Paul W. (Springer, 2019)
      In this paper, we consider the phenomenon of “pedagogical violence” — infliction of physical, social, emotional, or psychological pains, or threat of such pains that is either the means for or non-accidental by-products of education used on a systematic basis. Pedagogical violence is often used for promoting certain desired learning in students. Alternatively, it can emerge as a violent reaction in students and teachers to particular educational settings directed against other students or teachers. In this paper, we review some of the debates and controversial issues around pedagogical violence, and we use a variety of illustrative examples to explore in more detail what pedagogical violence means in particular contexts. We argue that pedagogical violence is a natural consequence of alienated instrumental education. We will look at teachers’ desire to avoid physical and psychosocial pedagogical violence. We specifically consider diverse forms of psychosocial pedagogical violence and its issues such as: summative assessment, epistemological pedagogical violence, students’ ambivalence around pedagogical violence, rehabilitating/avoiding pedagogical violence through a carnival. We finish with a reflection about what can be done to minimize pedagogical violence. Our analysis heavily relies on the Bakhtinian theoretical framework of critical ontological dialogism.
    • Unconditional quantile regression analysis of UK inbound tourist expenditures

      Sharma, Abhijit; Woodward, R.; Grillini, Stefano (2020-01)
      Using International Passenger Survey (2017) data, this paper employs unconditional quantile regression (UQR) to analyse the determinants of tourist expenditure amongst inbound tourists to the United Kingdom. UQR allows us to estimate heterogeneous effects at any quantile of the distribution of the dependent variable. It overcomes the econometric limitations of ordinary least squares and quantile regression based estimates typically used to investigate tourism expenditures. However, our results reveal that the effects of our explanatory variables change across the distribution of tourist expenditure. This has important implications for those tasked with devising policies to enhance the UK’s tourist flows and expenditures.
    • Perspectives on the future of manufacturing within the Industry 4.0 era

      Hughes, L.; Dwivedi, Y.K.; Rana, Nripendra P.; Williams, M.D.; Raghaven, V. (2020)
      The technological choices facing the manufacturing industry are vast and complex as the industry contemplates the increasing levels of digitization and automation in readiness for the modern competitive age. These changes broadly categorized as Industry 4.0, offer significant transformation challenges and opportunities, impacting a multitude of operational aspects of manufacturing organizations. As manufacturers seek to deliver increased levels of productivity and adaptation by innovating many aspects of their business and operational processes, significant challenges and barriers remain. The roadmap toward Industry 4.0 is complex and multifaceted, as manufacturers seek to transition toward new and emerging technologies, whilst retaining operational effectiveness and a sustainability focus. This study approaches many of these significant themes by presenting a critical evaluation of the core topics impacting the next generation of manufacturers, challenges and key barriers to implementation. These factors are further evaluated via the presentation of a new Industry 4.0 framework and alignment of I4.0 themes with the UN Sustainability Goals.
    • What doesnt kill you: Early life health and nutrition in early Anglo Saxon East Anglia

      Kendall, E.J.; Millard, A.; Beaumont, Julia; Gowland, R.; Gorton, Marise; Gledhill, Andrew R. (Springer Nature, 2020)
      Early life is associated with high vulnerability to morbidity and mortality - risks which can be reduced in infancy and early childhood through strategically high levels of parental or alloparental investment, particularly in the case of maternal breastfeeding. Recent evidence has supported links between early-life health and care patterns and long-term population health. This growing body of research regarding the broader impacts of infant-parent interactions transcends a traditional partitioning of research into discrete life stages. It also highlights implications of childhood data for our understanding of population health and behaviour. Skeletal and environmental data indicate that the 5-7th century cemeteries at Littleport and Edix Hill (Barrington A), Cambridgeshire represent populations of similar material culture but contrasting environments and health. The high prevalence of skeletal stress markers at Littleport indicates a community coping with unusual levels of biological stress, potentially a consequence of endemic malaria present in the marshy Fen environs. In contrast, Edix Hill was an inland site which exhibited lower skeletal stress marker prevalence comparable to wider British data for the early medieval period. Early life patterns relating to diet and physiological stress at Littleport (n=5) and Edix Hill (n=8) were investigated through analyses of carbon and nitrogen stable isotopes from incrementally-sampled deciduous dentine. Meaningful variation in isotopic values within and between populations was observed, and should be a focus of future interdisciplinary archaeological childhood studies.
    • Multigram scale synthesis of polycyclic lactones and evaluation of antitumor and other biological properties

      Grau, L.; Romero, M.; Privat-Contreras, C.; Presa, Daniela; Viñas, M.; Morral, J.; Pors, Klaus; Rubio-Martinez, J.; Pujol, M.D. (2020-01-01)
      An efficient four-step synthesis of tetracyclic lactones from 1,4-benzodioxine-2-carboxylic acid was developed. Ellipticine derivatives exhibit antitumor activity however only a few derivatives without carbazole subunit have been studied to date. Herein, several tetracyclic lactones were synthesized and biologically evaluated. Several compounds (2a, 3a, 4a and 5a) were found to be inhibitors of the Kras-Wnt pathway. The lactone 2a also exerted a potent inhibition of Tau protein translation and was shown to have capacity for CYP1A1-bioactivation. The results obtained are further evidence of the therapeutic potential of tetracyclic lactones related to ellipticine. Molecular modeling studies showed that compound 2a is inserted between helix α3 and α4 of the KRas protein making interactions with the hydrophobic residues Phe90, Glu91, Ile9364, Hie94, Leu133 and Tyr137and a hydrogen bond with residue Arg97.
    • Loss of CRMP2 O-GlcNAcylation leads to reduced novel object recognition performance in mice

      Muha, V.; Williamson, Ritchie; Hills, R.; McNeilly, A.D.; McWilliams, T.G.; Alonso, J.; Schimpl, M.; Leney, A.C.; Heck, A.J.R.; Sutherland, C.; et al. (2019-11-06)
      O-GlcNAcylation is an abundant post-translational modification in the nervous system, linked to both neurodevelopmental and neurodegenerative disease. However, the mechanistic links between these phenotypes and site-specific O-GlcNAcylation remain largely unexplored. Here, we show that Ser517 O-GlcNAcylation of the microtubule-binding protein Collapsin Response Mediator Protein-2 (CRMP2) increases with age. By generating and characterizing a Crmp2S517A knock-in mouse model, we demonstrate that loss of O-GlcNAcylation leads to a small decrease in body weight and mild memory impairment, suggesting that Ser517 O-GlcNAcylation has a small but detectable impact on mouse physiology and cognitive function.
    • Electronic Word of Mouth (eWOM) in the marketing context: A state of the art analysis and future directions

      Ismagilova, Elvira; Dwivedi, Y.K.; Slade, E.; Williams, M. (Springer International Publishing, 2017)
      This SpringerBrief offers a state of the art analysis of electronic word-of-mouth (eWOM) communications and its role in marketing. The book begins with an overview of traditional word-of-mouth (WOM) and its evolution to eWOM. It discusses the differences between traditional and online WOM. The book examines why people engage in eWOM communications, but also how consumers evaluate its persuasiveness. It also looks at the effects of eWOM. The book identifies current gaps in the eWOM research, but also highlights future directions for this growing field. eWOM is an important marketing technique in brand communications, and it plays an important role in modern e-commerce. Marketers become extremely interested in enhancing the power of eWOM developing loyalty programs and building brands. Studying the effect of eWOM can be beneficial for companies. This book should be a good resource for scholars and practitioners that need to understand the pervasive effects of eWOM.
    • Self identity and internal environmental locus of control: Comparing their influences on green purchase intentions in high-context versus low-context cultures

      Patel, J.D.; Trivedi, Rohitkumar; Yagnik, A. (2020-03)
      This study empirically examines the combined effect of two crucial internal consumer predispositions, self-identity (SI) and internal environmental locus of control (INELOC), among consumers in a collectivistic culture and an individualistic culture. The study validated the extended theory of planned behaviour to predict consumers' green purchase intentions. Structural equation modelling was used to analyse primary data collected from 365 American and 408 Indian respondents. Analysis revealed differences between the two cultures. Green self-identity influenced attitude more than perceived behavioural control among American consumers, while the reverse was true for Indian consumers. Conversely, INELOC positively and significantly affected only Indian consumers’ perceived behavioural control, not that of American consumers.
    • Understanding tradition: marital name change in Britain and Norway

      Duncan, Simon; Ellingsæter, A.L.; Carter, J. (Sage, 2019)
      Marital surname change is a striking example of the survival of tradition. A practice emerging from patriarchal history has become embedded in an age of de-traditionalisation and women’s emancipation. Is the tradition of women’s marital name change just some sort of inertia or drag, which will slowly disappear as modernity progresses, or does this tradition fulfil more contemporary roles? Are women and men just dupes to tradition, or alternatively do they use tradition to further their aims? We examine how different approaches - individualisation theory, new institutionalism and bricolage - might tackle these questions. This examination is set within a comparative analysis of marital surname change in Britain and Norway, using small qualitative samples. We find that while individualisation and new institutionalism offer partial explanations, bricolage offers a more adaptable viewpoint.
    • Ancient Mycobacterium leprae genomes from the mediaeval sites of Chichester and Raunds in England

      Kerudin, A.; Müller, R.; Buckberry, Jo; Knüsel, C.J.; Brown, T.A. (2019-12)
      We examined six skeletons from mediaeval contexts from two sites in England for the presence of Mycobacterium leprae DNA, each of the skeletons displaying osteological indicators of leprosy. Polymerase chain reactions directed at the species-specific RLEP multicopy sequence produced positive results with three skeletons, these being among those with the clearest osteological signs of leprosy. Following in-solution hybridization capture, sufficient sequence reads were obtained to cover >70% of the M. leprae genomes from these three skeletons, with a mean read depth of 4–10×. Two skeletons from a mediaeval hospital in Chichester, UK, dating to the 14th–17th centuries AD, contained M. leprae strains of subtype 3I, which has previously been reported in mediaeval England. The third skeleton, from a churchyard cemetery at Raunds Furnells, UK, dating to the 10th to mid-12th centuries AD, carried subtype 3K, which has been recorded at 7th–13th century AD sites in Turkey, Hungary and Denmark, but not previously in Britain. We suggest that travellers to the Holy Land might have been responsible for the transmission of subtype 3K from southeast Europe to Britain.
    • Estimation of Dulling Rate and Bit Tooth Wear Using Drilling Parameters and Rock Abrasiveness

      Mazen, Ahmed Z.; Rahmanian, Nejat; Mujtaba, Iqbal M.; Hassanpour, A. (2019)
      Optimisation of the drilling operations is becoming increasingly important as it can significantly reduce the oil well development cost. One of the major objectives in oil well drilling is to increase the penetration rate by selecting the optimum drilling bit based on offset wells data, and adjust the drilling factors to keep the bit in good condition during the operation. At the same time, it is important to predict the bit wear and the time to pull out the bit out of hole to prevent fishing jobs. Numerous models have been suggested in the literature for predicting the time to pull the bit out to surface rather than predict or estimate the bit wear rate. Majority of the available models are largely empirical and can be applied for limited conditions, and do not include all the drilling parameters such as the formation abrasiveness and bit hydraulic. In this paper, a new approach is presented to improve the drill bit wear estimation that consists of a combination of both Bourgoyne and Young (BY) drilling rate model and theory of empirical relation for the effects of rotary speed (RPM), and weight on bit (WOB) on drilling arte (ROP) and rate of tooth wear. In addition to the drilling parameters, the formation abrasiveness and the effect of the jet impact force of the mud have also been accounted to estimate the bit wear. The proposed model enables estimation of the rock abrasiveness, and that lead to calculate the dynamic dulling rate of the bit while drilling that used in more accurate to assess the bit tooth wear compared with the mechanical specific energy (MSE). Then the estimated dulling rate at the depth of pulling out is used to determine the dull grade of the bit. The technique is validated in five wells located in two different oil fields in Libya. All studied wells in this showed a good agreement between the actual bit tooth wear and the estimated bit tooth wear.
    • Investigating Ethical Decision Making in Marketing Research: An Exploratory Study Towards the Interaction of Different Moral Agents in Marketing Research

      Fukukawa, Kyoko; Reynolds, Nina L.; Bimpli, Iva
      The premise of this study is the in-depth exploration and investigation of the nature of Ethical Decision Making (EDM) in marketing research. More specifically, this research is concerned with exploring the understanding and the holistic conceptualisation of Ethical Decision Making (EDM) through the investigation of different moral agents in marketing research in the United Kingdom. In particular, marketing research researchers’ (MR researchers) and marketing research respondents’ (MR respondents) ethical judgements and behavioural intentions have been investigated based on two marketing research techniques that generate ethical issues; neuromarketing [NM] and autoethnography [AE], Despite the examination of the two aforementioned moral agents, at the heart of this thesis has been the investigation of MR researchers’ (un)willingness to adopt or practice (i.e. behavioural intentions) these marketing research techniques. This study employed a qualitative design and was initiated on descriptive behavioural ethics, in order to investigate MR researchers’ behavioural intentions, while it has a nonnative purpose towards norm generation in the field. Thus, the Theory of Planned Behaviour’ and the ‘General Theory of Marketing Ethics’ (i.e. H-V model) were applied for the initial theoretical considerations of this thesis. By utilising descriptive and nonnative ethical accounts, this study has found that Ethical Decision Making (EDM) in marketing research is grounded in a social contract ethics foundation of a multidimensional structural functionalistic premise. Within this ethical setting the MR researcher is considering the MR respondent’s decision making processes with regards to norm generation, governed by social consensus, social proof and conformity. This results from a multidimensional interdependent social interaction of the two moral agents. Finally, this thesis concludes that Ethical Decision Making (EDM) in marketing research is not conceptualised in a linear progressive manner, but it consists of numerous constructs that fit with each other in a rather loosely coupled modular manner depicting a rather complex and dynamic system of multilayered factors and multi-dimensional constructs.
    • Investigating the Existence, Cognitive Attributes and Potential Pathological Consequences of the Extreme Female Brain

      Lesk, Valerie E.; Waters, Gillian M.; Jones, Sarah L.
      The ‘extreme female brain’ (EFB) is derived from the empathising - systemising theory (E-S) which hypothesises that sex differences in cognition exist on a continuum, based on abilities in ‘empathising’ and ‘systemising’ (Baron-Cohen, 2003). The EFB profile; extreme empathising alongside deficient systemising, has received little attention in social cognitive neuroscience research, compared to the extreme male brain, which has advanced the knowledge of sex differences in the expression of autism. Currently, there is no solid evidence of a clinical pathology relating to the EFB nor a marker of cognition associated with a person’s ‘place’ on the E-S continuum. Here, an episodic memory paradigm with social and non-social conditions was given to participants along with measures of empathising and systemising. Scores on the social condition predicted where a person lies on the E-S continuum. The thesis then investigated the hypothesis that schizophrenia is expressed in the feminised profile (Badcock & Crepsi, 2006) and the presumption that empathising and systemising demonstrate a tradeoff. Elements of paranoia were associated with an empathising bias. However, a bias in systemising ability was associated with schizotypy along with a significant overlap in the expression of autistic traits and schizotypy. Therefore, schizophrenia as a whole is unlikely to be the pathology seen in the EFB, rather, the positive symptoms of schizophrenia. A trade-off between empathising and systemising was seen but only in participants over 36 years. These results have significant implications for assessment and treatment of neuropsychological disorders and provide more specific details on the potential EFB pathology. ii
    • Rheology and Pumping of Waxy Crude Oils: An experimental study of the yield stresses of waxy crude oils measured using a range of rheological techniques

      Benkreira, Hadj; Patel, Rajnikant; Abdelrahim, A.M.A.
      A major problem faced by the petroleum industry is the deposition of wax during the pumping of waxy crude oils. This precipitation occurs at “normal” temperature, typically 20-30°C in Libya. It could occur during the journey from well to terminal through hundreds of miles of pipelines. This kind of transportation is expensive in terms of pumping costs. The pumping has to be continuous; otherwise wax can build up in the pipeline, reducing the pumping or even stopping it. The property that defines this characteristic is the yield stress which depends on wax concentration and cooling rate. The build-up of paraffin and asphaltenes can lead to serious problems in formation, tanks, and pipelines. Blockages can be expensive and time-consuming to deal with; this is precisely the topic of this research. For this research, model and real waxy crude oils are formulated and their rheology systematically measured under various cooling rates to determine the yield stress. A pipeline loop has been designed to measure the start-up pressure of stagnant oil which has been allowed to precipitate wax. The start-up pressure and the thickness of deposited wax are used in a simple mathematical model to calculate the yield stress. This research thus provides two independent means of predicting the yield stress. This research studied three different waxy crude oils. An MCR-301 Anton Paar rheometer was used to measure the rheology of the oils, and a pipeline rig was used to obtain the start-up pressure to calculate the yield stress of each type of oil after different stoppage times. Also, the thickness of the precipitated wax is measured to calculate the yield stress precisely. The data show that the layer thickness has significant effect on the yield stress and start-up pressures and corresponding yield flow stresses have been found to underpin the crystallisation process of the wax and slow cooling rate produce stronger structures requiring higher stresses to fracture and induce flow. Also, longer shutdown times make these structures even stronger and therefore require even larger stresses for flow to commence.
    • Six Sigma Implementation in Middle East Organisations: An Empirical Study

      Hafeez, Khalid; Abdi, M. Reza; Ashri, Fahad H.
      In the last decade, the rapid economic development in the Middle East has encouraged organisations to implement modem quality management and strategic initiatives such as Six Sigma to ensure continuous improvement and achieved excellence. Six Sigma is a comprehensive business strategic quality programme and a systematic process improvement methodology for achieving, sustaining and maximising business success. The proper implementation of Six Sigma leads to breakthrough in profitability through ensuring quantum gains in product/service quality, customer satisfaction and productivity. This research presents an empirical exploratory and comparative study that aims and attempts to bridge the gap in the existing literature of Six Sigma by investigating the current implementation status of Six Sigma in organisations of three Middle East countries (namely, Saudi Arabia, Egypt and United Arab Emirates (UAE)). The reasons/benefits that encourage Middle East organisations to implement Six Sigma projects, the challenges commonly faced during implementation, the critical success factors (CSFs) for effective implementation and the organisations’ satisfaction with the implementation are investigated. The key issues of Six Sigma implementation and their criticality relating to the experience of the implementing process of Six Sigma projects are explored through an extensive review of the relevant literature. The data were collected from a combination of quantitative (232 questionnaires) and qualitative (74 semi-structured interviews) methodologies. The research covered 44 organisations from manufacturing and services sectors and large, small, and medium enterprises (SME) sizes, which have implemented or were implementing Six Sigma projects in the selected countries at the time of study. The study findings identified 15 significant reasons/benefits which encourages Middle East organisations to implement Six Sigma projects, 13 major challenges commonly faced during implementation, 19 CSFs for effective implementation and level of the organisations’ satisfaction with the implementation. Based on the research findings, a generic model for successful and effective implementation of Six Sigma in Middle East organisations is developed and proposed. The research concludes that Six Sigma implementation in Middle East organisations still in early stage, most organisations have outstanding opportunities to implement the Six Sigma project successfully and effectively with tangible and intangible benefits. In addition, all the responding organisations, which are actively implementing Six Sigma programme, regardless of their countries, sectors and sizes are highly satisfied with the implementation results. However, the research output highlights that an improvement culture must be developed and promoted throughout the organisation to ensure long-term benefit and sustainable success. Furthermore, the research makes recommendations on development of an implementation strategy in Middle East organisations. Finally, a number of suggestions are made for future research.
    • Secondary Metabolites from Xylaria Endophytes: The isolation and structure elucidation of secondary metabolites from Xylaria endophytes by chemical and spectroscopic methods

      Maitland, Derek J.; Edwards, Raymond L.; Al-Busaidi, Harith
      This thesis describes the isolation and structure elucidation of secondary metabolites from a number of endophytic Xylaria fungi. Six Xylaria endophytes were surface cultured on an aqueous malt extract-glucose medium. The fungus A311R, from a palm tree in Thailand, produced nonane-1,2,3-tricarboxylic acid, which was isolated for the first time as a natural product. Also isolated from the same fungus was spiculisporic acid; the first instance of isolation from a Xylaria fungus. The fungus 6RD12 produced cycloepoxydon, which was isolated for the first time from a Xylaria fungus, and 4,5,6-trihydroxy-3-propyl-3,4,6,7-tetrahydro-l//-isochromen- 8(5//)-one, which is a novel compound. The fungi A217R and A517R produced cytochalasin D, (S)-mellein and (3S,4S)-4-hydroxymellein as main secondary metabolites suggesting that the two fungi are the same species. The fungus X04 (Xylaria cf. juruensis) produced 2-Hydroxy-5-ethoxy-3-methylcyclohexa-2,5-dien- 1,4-dione as a novel compound, coriloxin as the main secondary metabolite in addition to (R)-mellein and a mixture of two stereoisomers of the 4-Hydroxymellein. The fungus 6RD8 produced (S)-Omethylmellein as the main secondary metabolite. l
    • Identification and characterisation of antiplatelet antibodies in ITP patients

      Lindsey, Nigel J.; Aghabeigi, Nabiollah
      The autoimmune disease known as autoimmune thrombocytopenic purpura (ITP) is clinically defined by a low numbers of platelets in the circulation blood. Anti-platelet antibodies bind to glycoprotein molecules on the membranes of platelets and result in their dysfunction and destruction. Despite a growing body of information about ITP, it is difficult to isolate and characterise anti-platelet antibodies, because only limited monoclonal antibodies are available from ITP patients. This study used a phage display system to recognise Fab anti-platelet antibodies. Anti-platelet Fab-expressing phage was isolated by sequential panning of an ITP Fab library against normal non-ITP platelets. After isolation, the anti-platelet Fab-expressing phage was characterised by ELISA and Western blotting. The Fab-bearing phage pool obtained from five rounds of panning was analysed in order to determine its anti-platelet reactivity. Of the phage colonies obtained, 100 colonies of different sizes were randomly selected for reaction with whole platelets, using Ml3 phage as a negative control. 12 colonies of them had strong reactions against the whole platelet preparation, but only four colonies showed substantial reactivity against the lysed platelet preparation (lysate). Colony S7 showed highest the greatest degree of binding to both the lysate and the whole platelet preparation. The specificity of the four colonies (S2, S7, S8 and S9) that had strong positive reactions against platelet antigens was determined for the glycoprotein component GP Ilb/IIIa. Further characterisation of the proteins in the lysate preparation was carried out using blotting techniques. The protein content of the four Fab-bearing phage colonies was quantified under the non-reducing conditions of Western blotting to evaluate their ability to recognise platelet antigens. Three of the four colonies showed three bands representing proteins with different molecular weights. Each of these three colonies had one band that corresponded to a protein of molecular weight 92 kD. The fourth colony showed only a single band, but this band also corresponded to a 92-kD protein.