61 research outputs found
Ruptures in remembrance : trauma, utterance and patterns in survivor testimony
As eyewitnesses and victims of the Holocaust, survivors have been traumatised by
their experiences; indeed, memories of this time continue to haunt them into the
present day. But whilst a great deal of research has been conducted into the
transferential and representational problems survivors encounter whilst giving voice
to their experiences, fewer studies have questioned how the trauma of living through
this genocide may have affected the ways in which eyewitnesses remember - and in
turn relay - their turbulent pasts. Mark Roseman has recently examined how
‘interesting inaccuracies [often occur] in...[survivor] memory’ which seem to follow
a recognizable ‘pattern’. However, no one has yet compared the different testimonies
produced by a single survivor over time, in order to determine whether a ‘pattern’
occurs consistently in their Holocaust narrations. In this thesis, I compare the different
oral and written testimonials that three survivors - Anita Lasker-Wallfisch, Trade Levi
and Leon Greenman - have given since the end of the war. I have found that there are
a series of interesting ‘variations’ and speech disturbances that can be tracked through
these survivors’ utterances from their earliest accounts to their most recent
depositions. I posit that these discrepancies are the result of the trauma of Lasker,
Levi and Greenman’s Holocaust experiences, and have found ‘patterns’ in their
testimonies which endorse the theory that whilst recounting certain memories these
survivors are plagued by symptoms of post-traumatic stress disorder. In asserting this,
I am not attempting to undermine or dispute the validity of these survivors’ memories.
In fact, by focusing on how eyewitnesses re-configure their recollections in discourse,
my findings support the veracity of their accounts - by showing that survivors sculpt
their testimonies into a defensive framework that enables them to counteract ‘the pain
of remembering’, by paradoxically giving voice to these very memories of distress
Extensive Genomic Variation within Clonal Complexes of Neisseria meningitidis
Meningococcal disease is a widely distributed complex disease affecting all age categories. It can cause severe meningitis and septicemia, especially in unvaccinated infants and young children. The causative agent, Neisseria meningitidis (Nm), can be phenotypically and genetically differentiated into serogroups and sequence types (STs) and has a highly dynamic population structure. To obtain a deeper understanding of the epidemiology of Nm, we sequenced seven Nm genomes. Large-scale genomic analysis was conducted with these 7 Nm genomes, 27 additional Nm genomes from GenBank, and 4 other Neisseria genomes. We observed extensive homologous recombination in all gene functional categories among different Nm genomes. Homologous recombination is so frequent that it has resulted in numerous chimeric open reading frames, including genes in the capsule biosynthesis cluster and loci targeted by commercial vaccines. Our results reveal that, despite widespread use, evolutionary relationships inferred from the standard seven-gene multilocus sequence typing (MLST) method could not predict virulence gene content or strain phenotype. In fact, up to 28% of the virulence-associated genes could differ between strains of identical STs. Consistent with previous studies, we found that allelic recombination is also associated with alterations in antibiotic susceptibility. Overall, these findings emphasize the extensive genomic plasticity of Nm and the limitations of standard molecular methods to quantify this genotypic and phenotypic diversity
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
Population genetic structure, antibiotic resistance, capsule switching and evolution of invasive pneumococci before conjugate vaccination in Malawi
INTRODUCTION:
Pneumococcal infections cause a high death toll in Sub Saharan Africa (SSA) but the recently rolled out pneumococcal conjugate vaccines (PCV) will reduce the disease burden. To better understand the population impact of these vaccines, comprehensive analysis of large collections of pneumococcal isolates sampled prior to vaccination is required. Here we present a population genomic study of the invasive pneumococcal isolates sampled before the implementation of PCV13 in Malawi.
MATERIALS AND METHODS:
We retrospectively sampled and whole genome sequenced 585 invasive isolates from 2004 to 2010. We determine the pneumococcal population genetic structure and assessed serotype prevalence, antibiotic resistance rates, and the occurrence of serotype switching.
RESULTS:
Population structure analysis revealed 22 genetically distinct sequence clusters (SCs), which consisted of closely related isolates. Serotype 1 (ST217), a vaccine-associated serotype in clade SC2, showed highest prevalence (19.3%), and was associated with the highest MDR rate (81.9%) followed by serotype 12F, a non-vaccine serotype in clade SC10 with an MDR rate of 57.9%. Prevalence of serotypes was stable prior to vaccination although there was an increase in the PMEN19 clone, serotype 5 ST289, in clade SC1 in 2010 suggesting a potential undetected local outbreak. Coalescent analysis revealed recent emergence of the SCs and there was evidence of natural capsule switching in the absence of vaccine induced selection pressure. Furthermore, majority of the highly prevalent capsule-switched isolates were associated with acquisition of vaccine-targeted capsules.
CONCLUSIONS:
This study provides descriptions of capsule-switched serotypes and serotypes with potential to cause serotype replacement post-vaccination such as 12F. Continued surveillance is critical to monitor these serotypes and antibiotic resistance in order to design better infection prevention and control measures such as inclusion of emerging replacement serotypes in future conjugate vaccines
Phasevarions Mediate Random Switching of Gene Expression in Pathogenic Neisseria
Many host-adapted bacterial pathogens contain DNA methyltransferases (mod genes) that are subject to phase-variable expression (high-frequency reversible ON/OFF switching of gene expression). In Haemophilus influenzae, the random switching of the modA gene controls expression of a phase-variable regulon of genes (a “phasevarion”), via differential methylation of the genome in the modA ON and OFF states. Phase-variable mod genes are also present in Neisseria meningitidis and Neisseria gonorrhoeae, suggesting that phasevarions may occur in these important human pathogens. Phylogenetic studies on phase-variable mod genes associated with type III restriction modification (R-M) systems revealed that these organisms have two distinct mod genes—modA and modB. There are also distinct alleles of modA (abundant: modA11, 12, 13; minor: modA4, 15, 18) and modB (modB1, 2). These alleles differ only in their DNA recognition domain. ModA11 was only found in N. meningitidis and modA13 only in N. gonorrhoeae. The recognition site for the modA13 methyltransferase in N. gonorrhoeae strain FA1090 was identified as 5′-AGAAA-3′. Mutant strains lacking the modA11, 12 or 13 genes were made in N. meningitidis and N. gonorrhoeae and their phenotype analyzed in comparison to a corresponding mod ON wild-type strain. Microarray analysis revealed that in all three modA alleles multiple genes were either upregulated or downregulated, some of which were virulence-associated. For example, in N. meningitidis MC58 (modA11), differentially expressed genes included those encoding the candidate vaccine antigens lactoferrin binding proteins A and B. Functional studies using N. gonorrhoeae FA1090 and the clinical isolate O1G1370 confirmed that modA13 ON and OFF strains have distinct phenotypes in antimicrobial resistance, in a primary human cervical epithelial cell model of infection, and in biofilm formation. This study, in conjunction with our previous work in H. influenzae, indicates that phasevarions may be a common strategy used by host-adapted bacterial pathogens to randomly switch between “differentiated” cell types
Towards a Wolbachia Multilocus Sequence Typing system : discrimination of Wolbachia strains present in Drosophila species
Author Posting. © The Author(s), 2006. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Current Microbiology 53 (2006): 388-395, doi:10.1007/s00284-006-0054-1.Among the diverse maternally inherited symbionts in arthropods, Wolbachia are the most common and infect over 20% of all species. In a departure from traditional genotyping or phylogenetic methods relying on single Wolbachia genes, the present study represents an initial Multilocus Sequence Typing (MLST) analysis to discriminate closely related Wolbachia pipientis strains, and additional data on sequence diversity in Wolbachia. We report new phylogenetic characterization of four genes (aspC, atpD, sucB and pdhB), and provide an expanded analysis of markers described in previous studies (16S rDNA, ftsZ, groEL, dnaA and gltA). MLST analysis of the bacterial strains present in sixteen different Drosophila-Wolbachia associations detected four distinct clonal complexes that also corresponded to maximum-likelihood identified phylogenetic clades. Among the sixteen associations analyzed, six could not be assigned to MLST clonal complexes and were also shown to be in conflict with relationships predicted by maximum-likelihood phylogenetic inferences. The results demonstrate the discriminatory power of MLST for identifying strains and clonal lineages of Wolbachia and provide a robust foundation for studying the ecology and evolution of this widespread endosymbiont.This work was partially supported by intramural funds of the University of Ioannina to K. Bourtzis, by grants to J.J. Wernegreen from the National Institutes of Health (R01 GM62626-01) and the NASA Astrobiology Institute (NNA04CC04A), and to J.H. Werren and J.J. Wernegreen from the National Science Foundation (EF-0328363)
The rise of \u27women\u27s poetry\u27 in the 1970s an initial survey into new Australian poetry, the women\u27s movement, and a matrix of revolutions
sodC-Based Real-Time PCR for Detection of Neisseria meningitidis
Real-time PCR (rt-PCR) is a widely used molecular method for detection of
Neisseria meningitidis (Nm). Several rt-PCR assays for Nm
target the capsule transport gene, ctrA. However, over
16% of meningococcal carriage isolates lack ctrA,
rendering this target gene ineffective at identification of this sub-population
of meningococcal isolates. The Cu-Zn superoxide dismutase gene,
sodC, is found in Nm but not in other
Neisseria species. To better identify Nm, regardless of
capsule genotype or expression status, a sodC-based TaqMan
rt-PCR assay was developed and validated. Standard curves revealed an average
lower limit of detection of 73 genomes per reaction at cycle threshold
(Ct) value of 35, with 100% average reaction efficiency
and an average R2 of 0.9925. 99.7% (624/626) of Nm isolates
tested were sodC-positive, with a range of average
Ct values from 13.0 to 29.5. The mean sodC
Ct value of these Nm isolates was 17.6±2.2 (±SD).
Of the 626 Nm tested, 178 were nongroupable (NG) ctrA-negative
Nm isolates, and 98.9% (176/178) of these were detected by
sodC rt-PCR. The assay was 100% specific, with all
244 non-Nm isolates testing negative. Of 157 clinical specimens tested,
sodC detected 25/157 Nm or 4 additional specimens compared
to ctrA and 24 more than culture. Among 582 carriage specimens,
sodC detected Nm in 1 more than ctrA and
in 4 more than culture. This sodC rt-PCR assay is a highly
sensitive and specific method for detection of Nm, especially in carriage
studies where many meningococcal isolates lack capsule genes
The Enterics for Global Health (EFGH) Shigella Surveillance Study in Malawi
Background: Malawi is among 7 countries participating in the Enterics for Global Health (EFGH) Shigella surveillance study, which aims to determine the incidence of medically attended diarrhea attributed to Shigella, a leading bacterial cause of diarrhea in children in low-resource settings.
Methods: We describe the EFGH study site in the densely populated informal settlement of Ndirande Township, Blantyre, Malawi. We explore the site’s geographical location, demographic characteristics, and the healthcare-seeking behavior of its population, particularly for childhood diarrhea. We also describe the management of childhood diarrhea at the health facility, and the associated challenges to attaining optimum adherence to local and national guidelines at the site.
Conclusions: Our overarching aim is to improve global health through understanding and mitigating the impact of diarrhea attributed to Shigella
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Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
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