Nicholas Martin

Dried Blood Spot Proteomics: Surface Extraction of Endogenous Proteins Coupled with Automated Sample Preparation and Mass Spectrometry Analysis

AbstractDried blood spots offer many advantages as a sample format including ease and safety of transport and handling. To date, the majority of mass spectrometry analyses of dried blood spots have focused on small molecules or hemoglobin. However, dried blood spots are a potentially rich source of protein biomarkers, an area that has been overlooked. To address this issue, we have applied an untargeted bottom-up proteomics approach to the analysis of dried blood spots. We present an automated and integrated method for extraction of endogenous proteins from the surface of dried blood spots and sample preparation via trypsin digestion by use of the Advion Biosciences Triversa Nanomate robotic platform. Liquid chromatography tandem mass spectrometry of the resulting digests enabled identification of 120 proteins from a single dried blood spot. The proteins identified cross a concentration range of four orders of magnitude. The method is evaluated and the results discussed in terms of the proteins identified and their potential use as biomarkers in screening programs. Figureᅟ

Native Liquid Extraction Surface Analysis Mass Spectrometry: Analysis of Noncovalent Protein Complexes Directly from Dried Substrates

AbstractLiquid extraction surface analysis (LESA) mass spectrometry is a promising tool for the analysis of intact proteins from biological substrates. Here, we demonstrate native LESA mass spectrometry of noncovalent protein complexes of myoglobin and hemoglobin from a range of surfaces. Holomyoglobin, in which apomyoglobin is noncovalently bound to the prosthetic heme group, was observed following LESA mass spectrometry of myoglobin dried onto glass and polyvinylidene fluoride surfaces. Tetrameric hemoglobin [(αβ)24H] was observed following LESA mass spectrometry of hemoglobin dried onto glass and polyvinylidene fluoride (PVDF) surfaces, and from dried blood spots (DBS) on filter paper. Heme-bound dimers and monomers were also observed. The ‘contact’ LESA approach was particularly suitable for the analysis of hemoglobin tetramers from DBS. Graphical Abstractᅟ

Challenges and opportunities in mass spectrometric analysis of proteins from dried blood spots

Dried blood spots (DBS) have been used as a clinical sample format for over 50 years, and have been analyzed for small molecules and metabolites by mass spectrometry (MS) since the early 1990s. In the meantime, MS has become the tool of choice in proteomics. Despite this obvious avenue of scientific investigation, the marriage of MS and DBS protein analysis has been comparatively recent. DBS are a potentially rich source of protein biomarkers that remain to be exploited. This article focuses on the progress made in the mass spectrometric analysis of proteins from DBS and discusses the benefits and challenges facing this emerging field.

Hemoglobin variant analysis of whole blood and dried blood spots by MS

MS allows for the unequivocal diagnosis of hemoglobin variants, or hemoglobinopathies. Hemoglobinopathies are the most common inherited disorder and there is a need for rapid detection of clinically significant variants, such as sickle hemoglobin, which is responsible for sickle cell disease. In this review, we describe the development of MS approaches for the determination of hemoglobin variants from both whole blood samples and dried blood spots. MS approaches that are suitable for population screening are discussed, as are recent advances in direct surface analysis of dried blood spots.

Images of Schiller in National Socialist Germany

The essay analyses attitudes to Schiller in Germany between 1933 and 1945 in order to establish to what extent his character and work, however interpreted, provided a rallyingpoint for endorsers of the National Socialist regime as well as for some of its opponents. The nature of these attitudes is investigated, together with the related question of Schiller’s political and ideological malleability. Analysis of engagements with Schiller in this period reveals that there was no single, monolithic National Socialist “Schillerbild”. While Nazi treatments of Schiller were manipulative in the extreme and drew heavily on existing myths surrounding the poet, they were anything but consistent or uniform.

'Ewig verbundene Geister': Thomas Mann's Re-engagement with Nietzsche, 1943–1947

Abstract During the mid-1940s, Thomas Mann made determined and sustained efforts to explicate and account for Germanys catastrophic wager with the dark forces of National Socialism. In Manns fictional writing of the period 1943–1947 and in his more discursive texts, Friedrich Nietzsche emerges as a key figure in these attempts to contextualize Germanys Faustian bargain. After a consideration of Nietzsches presence (and absence) in the novel Doktor Faustus, the article examines in detail the case Mann presents in his essay Nietzsches Philosophie im Lichte unserer Erfahrung (1947). It is argued that, in this essay, Mann revisits and to a large extent re-affirms his earlier engagements with Nietzsche. The essays apparent aim is to situate Nietzsche within recent German experience, yet beneath the objective reckoning with Germanys fate Mann undertakes a self-examination which tackles the question of Nietzsches intellectual and emotional magnetism. Within this framework Mann discusses, often in a highly self-critical manner, questions of suffering, intellectual affinity and, most important of all, love. Manns efforts to distance himself from Nietzsche serve only to underscore the extent of his debt to this enthralling yet deeply problematic figure. In the immediate post-war period, Manns critical admiration for Nietzsches character emerges essentially unchanged, alongside an enduring sympathy with his fate.