1,720,984 research outputs found
The Translational Future of Stress Neurobiology and Psychosis Vulnerability: A Review of the Evidence
Get PDF: Psychosocial stress is a well-established risk factor for psychosis, yet the neurobiological mechanisms underlying this relationship have yet to be fully elucidated. Much of the research in this field has investigated hypothalamic-pituitary-adrenal (HPA) axis function and immuno-inflammatory processes among individuals with established psychotic disorders. However, as such studies are limited in their ability to provide knowledge that can be used to develop preventative interventions, it is important to shift the focus to individuals with increased vulnerability for psychosis (i.e., high-risk groups). In the present article, we provide an overview of the current methods for identifying individuals at high-risk for psychosis and review the psychosocial stressors that have been most consistently associated with psychosis risk. We then describe a network of interacting physiological systems that are hypothesised to mediate the relationship between psychosocial stress and the manifestation of psychotic illness and critically review evidence that abnormalities within these systems characterise high risk populations. We found that studies of high-risk groups have yielded highly variable findings, likely due to (i) the heterogeneity both within and across high-risk samples, (ii) the diversity of psychosocial stressors implicated in psychosis, and (iii) that most studies examine single markers of isolated neurobiological systems. We propose that to move the field forward, we require well-designed, large- scale translational studies that integrate multi-domain, putative stress-related biomarkers to determine their prognostic value in high-risk samples. We advocate that such investigations are highly warranted, given that psychosocial stress is undoubtedly a relevant risk factor for psychotic disorders
NMDAR-antibody encephalitis: psychopathology and immunobiology
Get PDFAutoimmune encephalopathies are immunotherapy-responsive brain diseases mediated by
autoantibodies against cell surface antigens. NMDAR-antibody encephalitis (NMDAR-Ab-E) is an
autoimmune encephalopathy mediated by IgG against the NR1 NMDA receptor subunit. The illness
has a psychiatric onset in most and an association with ovarian teratoma (OT) in a third. This thesis
explores the psychopathology and immunobiology of NMDAR-Ab-E; it focuses on the pattern and
evolution of mental state abnormalities and serological and cellular measures of autoimmunising
mechanisms.
A systematic review identified 464 individually reported patients with more detail than ‘psychiatric’
and/or ‘behavioural’. Granular lower-level phenomena were grouped into higher-level categories:
behaviour (68%), psychosis (67%), mood (47%), catatonia (30%), and sleep (21%). These had a
propensity to overlap within individual patients, most clearly in psychiatric-described reports (221/329,
67% vs 96/118, 81%). Network analysis suggested a complex pattern of disorganisation, disinhibition,
and affective instability rather than sub-groups of patients with simple syndromes (network density and
median closeness centrality of 1 in the psychiatric-described group). Further detailed interviews (n=5)
revealed temporal progression: complete insomnia and depressive mood develop early, possessionlike/
drugged-dissociative appearance during the psychosis, and developmental regression and
episodic amnesia as late features. Reductive framing as atypical/organic psychosis or delirium could
help focus clinical recognition. Lumbar puncture in acute psychiatric services needs to expand and
comparison with primary psychoses would help focus how far.
Using a live cell-based assay (CBA) with a 1:40 end-point dilution cut-off, 13/286 samples (5%) from
bipolar depression, 12/101 (12%) from acute mania, 5/57 (9%) from traumatic brain injury (TBI) and
3/55 (5%) from healthy volunteer cohorts were NR1-IgG positive. 31 cerebrospinal fluid (CSF) samples
from the TBI cohort were negative including two whose serum pair was positive. In contrast, 34/39
(87%) of NMDAR-Ab-E sera paired with CSF NR1-IgG positive samples were detectable at 1:40 and
39/39 at 1:20. Overlapping NR1-IgG levels meant that level could not fully discriminate between groups
and a N368Q NR1 mutation abrogated binding in 18/20 (90%) comparator group positive samples
suggesting that these were not false positives. However, no positive samples from the comparator
group bound neurons, unlike 70% of the selected NMDAR-Ab-E positive sera. Therefore, the NMDARAb-
E NR1-IgG were probably of greater affinity and/or polyclonality compared to the comparators,
consistent with a more fully realised autoimmunisation process.
Live CBAs for IgM and IgA NR1 autoantibodies were developed. NR1-IgM was common in NMDARAb-
E (121/285, 42% samples) and persistent (up to 2555 days post-onset). There was a timedependent
positive serum NR1-IgA association with OT (OR 6.32 P=0.005 <40 days post-onset). NR1-
IgG and NR1-IgA but not NR1-IgM were common in tumour fluid, cultured explants produced NR1-IgG
with and without activation cytokines, flow cytometry detected B cells from naïve through to classswitched
memory and antibody-secreting phenotypes, and GC-like structures with BCL6+AID+ B cells
and CD21+ sustentacular meshwork were found histologically. Ultrasound-guided fine needle
aspiration (FNA) of cervical lymph nodes (LN) in patients with and without OT successfully detected
distinct population frequencies in transitional B cells, T follicular helper cells (TfH), and CD83+ B cells.
Cultured LN cells from three patients with fully resected OTs did not produce NR1-IgG whereas those
from a patient with a partially treated OT and a relapsing patient without an OT did produce NR1-IgG.
LN cells from this relapsing patient also produced NR1-IgG during remission. These data consolidate
the status of NMDAR-Ab-E-associated OTs as tertiary lymphoid organs and provide direct evidence of
secondary lymphoid organ involvement in pathogenesis.
The two areas converge: the immunological findings suggest early autoimmunising events that can
propagate if left unchecked and a refined psychopathologic description could help better identify cases
during this window of opportunity
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
