90 research outputs found
Immunophoretic rapid diagnostic tests as a source of immunoglobulins for estimating malaria sero-prevalence and transmission intensity.
Get PDFBACKGROUND: Sero-epidemiological methods are being developed as a tool for rapid assessment of malaria transmission intensity. Simple blood collection methods for use in field settings will make this more feasible. This paper describes validation of such a method, by analysing immunoglobulins from blood retained within immunophoretic rapid diagnostic tests (RDTs) for Plasmodium falciparum. RDTs are now widely used for the diagnosis of malaria and estimation of parasite rates, and this method represents a further use for these devices in malaria control. METHODS: Immunoglobulins eluted from RDTs, designed to detect parasite histidine rich protein-2 (HRP-2), were analysed by indirect ELISA for IgG recognizing the P. falciparum blood stage antigens merozoite surface protein-1(19) (MSP-1(19)) and apical membrane antigen-1 (AMA-1). Optimal storage conditions for RDTs were evaluated by comparing antibody responses from RDTs stored in dry or humid conditions at 4 degrees C or at ambient temperature (with or without air-conditioning) for 7, 31 or 70 days. Antibody levels estimated using 3,700 RDT samples from attendees at health facilities in North-eastern Tanzania were compared with contemporaneously collected filter paper blood spots (FPBS) and used to estimate seroconversion rates. RESULTS: Storage of RDTs at 4 degrees C was optimal for immunoglobulin recovery but short-term storage at ambient temperatures did not substantially affect anti-malarial IgG levels. Results from RDTs were comparable with those from FPBSs, for both antigens. RDT-generated titres tended to be slightly higher than those generated from FPBSs, possibly due to greater recovery of immunoglobulins from RDTs compared to filter paper. Importantly, however, RDT-based seroconversion rates, and hence serological estimates of malaria transmission intensity, agreed closely with those from FPBSs. CONCLUSION: RDTs represent a practical option for collecting blood for sero-epidemiological surveys, with potential cost and logistical advantages over filter paper and other blood collection methods. RDT-based seroepidemiology can be incorporated into routine monitoring of malaria endemicity, providing information to supplement parasite prevalence rates and generating rapid, robust assessment of malaria transmission intensity at minimal extra cost
Serological markers suggest heterogeneity of effectiveness of malaria control interventions on Bioko Island, equatorial Guinea.
Get PDFBACKGROUND: In order to control and eliminate malaria, areas of on-going transmission need to be identified and targeted for malaria control interventions. Immediately following intense interventions, malaria transmission can become more heterogeneous if interventions are more successful in some areas than others. Bioko Island, Equatorial Guinea, has been subject to comprehensive malaria control interventions since 2004. This has resulted in substantial reductions in the parasite burden, although this drop has not been uniform across the island. METHODS/PRINCIPAL FINDINGS: In 2008, filter paper blood samples were collected from 7387 people in a cross-sectional study incorporating 18 sentinel sites across Bioko, Equatorial Guinea. Antibodies were measured to P. falciparum Apical Membrane Antigen-1 (AMA-1) by Enzyme Linked Immunosorbent Assay (ELISA). Age-specific seropositivity rates were used to estimate seroconversion rates (SCR). Analysis indicated there had been at least a 60% decline in SCR in four out of five regions on the island. Changes in SCR showed a high degree of congruence with changes in parasite rate (PR) and with regional reductions in all cause child mortality. The mean age adjusted concentration of anti-AMA-1 antibodies was mapped to identify areas where individual antibody responses were higher than expected. This approach confirmed the North West of the island as a major focus of continuing infection and an area where control interventions need to be concentrated or re-evaluated. CONCLUSION/INTERPRETATION: Both SCR and PR revealed heterogeneity in malaria transmission and demonstrated the variable effectiveness of malaria control measures. This work confirms the utility of serological analysis as an adjunct measure for monitoring transmission. Age-specific seroprevalence based evidence of changes in transmission over time will be of particular value when no baseline data are available. Importantly, SCR data provide additional evidence to link malaria control activities to contemporaneous reductions in all-cause child mortality
Comparison of selectivities of reversed-phase high-performance liquid chromatography, capillary zone electrophoresis and micellar capillary electrophoresis in the separation of neurohypophyseal peptides and analogues
No full textDetermination of l-thyroxine in reference serum preparations as the o-phthalaldehyde-N-acetylcysteine derivative by reversed-phase liquid chromatography with electrochemical detection
No full textIdentification of gonadorelin (LHRH) derivatives: Comparison of reversed-phase high-performance liquid chromatography and micellar electrokinetic chromatography
No full text‘Better to Let Scandal Arise than to Relinquish the Truth’: The Cases of Conscience of the Masters of Paris in the Thirteenth Century.
Get PDFThis volume addresses the ways in which institutions ‘did or did not constrain, enable and inflect the substantive thinking of individuals’ (see the introduction to this volume, p. 25). A number of the chapters explore this theme by identifying ways in which scholastic authors developed their own position within the boundaries imposed by institutional loyalties. Fitzpatrick’s and Linde’s chapters in this volume, for example, show how, at the turn of the thirteenth and fourteenth centuries, scholastic debate simultaneously pushed forward intellectual arguments and defined the parameters of disputes between Dominicans, Franciscans and the secular clergy. In contrast, quodlibets dealing with cases of conscience, the subject of this chapter, are something of an exceptional case in scholastic thought: moral quodlibets usually did not correspond directly to the syllabus organized around commentaries on the Sentences and they addressed questions which were not in the strictest sense theological, but which related to pastoral care. This chapter argues that responses to moral quodlibets should be understood neither as personal responses to a controversy, nor as attempts to carve out a position in a debate between rival ‘schools’. Rather, they are best explained as interventions within a separate genre of penitential thought and have a close relationship with manuals for confessors. In penitential manuals, the imperative on the author was less to devise appropriate responses to open questions and more to offer practical advice on how one should act. This was no less true of the moral quodlibets answered by theology masters. When masters gave responses within this genre, they found themselves constrained and enabled by institutions, but in a rather different way from when they answered questions in other kinds of theology
Tobacco use and interventions among Arizona lesbian, gay, bisexual and transgender people
Get PDFabstract: The present study, part of a larger effort regarding the health needs of LGBT Arizonans, focuses on tobacco use and intervention strategies. It was funded by the Arizona Department of Health Services and sponsored by southern Arizona’s LGBT community center, Wingspan.Includes bibliographical references (p. 19-21)
Immune responses to Plasmodium falciparum and autoimmunity: investigating common gene regulatory networks in a large-scale study from Burkina Faso.
No full textNarratives of Collaboration in Post-War France, 1944 – 1974
Get PDFArguing that literary narratives (whether fictional or autobiographical) can provide an important way in which the past is accessed and understood, this thesis uses such narratives to compare and contrast cultural representations of collaboration with the Gaullist political accounts described in Henry Rousso’s Le Syndrome de Vichy. Following the introduction, chapter one examines the perception and characteristics of collaboration, providing a broad analysis of collaboration and collaborators which frames later chapters. There follows a discussion of the generic boundaries between history, autobiography and fiction, showing that novels can contain many of the attributes conventionally ascribed to historical texts, as well as having a freedom of form which allows them to examine and relate subjects not allowed to historical accounts. Next, selected novels (by Marcel Aymé, Jean-Louis Bory, Marie Chaix, Céline, Jean-Louis Curtis, Jean Dutourd, Pascal Jardin, Patrick Modiano, Saint-Loup, and Michel Tournier) are analysed at length to examine how specific forms of collaboration have been understood, and how they subvert Rousso’s schema of repression or marginalisation of the phenomenon. Novels written in the immediate aftermath of the war actually gave a convincing representation of collaboration and the everyday wartime experience, contrasting with the ‘official’ story which sought to forget collaboration. Representations of intellectual and cultural collaboration show that, contrary to de Gaulle’s attempts to portray France as a nation of resisters, high-profile figures from these circles offered a more persuasive alternative to this view. This is also shown to be the case for depictions of military and paramilitary collaboration, which openly describe armed and violent collaboration, challenging and contrasting with the Gaullist representation of mass resistance supported by the civil population. Finally, familial memories are used to revaluate the mode rétro in light of earlier chapters. Although this phenomenon found innovative ways to view the war, it did not represent a wholly new, or more open, account, and was subject to its own repressions and distortions
Serology: a robust indicator of malaria transmission intensity?
No full textTo estimate the burden of malarial disease, and evaluate the likely effects of control strategies, requires reliable predictions of malaria transmission intensity. It has long been suggested that antimalarial antibody prevalences could provide a more accurate estimate of transmission intensity than traditional measures such as parasite prevalence or entomological inoculation rates, but there has been no systematic evaluation of this approach. Now, the availability of well characterized malarial antigens allows us to test whether serological measurements provide a practical method for estimating transmission. Here we present a suggested methodology, highlight the advantages and shortcomings of serological measurements of malaria transmission and identify areas in which further work is desirable
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