45 research outputs found
Changes in globus pallidus with (pre)term kernicterus
OBJECTIVE: We report serial magnetic resonance (MR) and sonographic
behavior of globus pallidus in 5 preterm and 3 term infants with
kernicterus and describe the clinical context in very low birth weight
preterm infants. On the basis of this information, we suggest means of
diagnosis and prevention. METHODS: Charts and MR and ultrasound images of
5 preterm infants and 3 term infants with suspected bilirubin-associated
brain damage were reviewed. Included were preterm infants with severe
hearing loss, quadriplegic hypertonia, and abnormal hypersignal of globus
pallidus on T2-weighted MR imaging (MRI). In 1 infant who died on day 150,
the diagnosis was confirmed during the neonatal period. The others were
picked up as outpatients and scanned at 12 or 22 months' corrected age.
Three instances of term kernicterus were included for comparison of serial
MRI in the neonatal period and early infancy: they were caused by
glucose-6-phosphate dehydrogenase deficiency, urosepsis, and dehydration
plus fructose 1-6 biphosphatase deficiency. RESULTS: Five preterm infants
of 25 to 29 weeks' gestational age presented with total serum bilirubin
(TSB) levels below exchange transfusion thresholds commonly advised. Mixed
acidosis was present in 3 infants around the TSB peak. The
bilirubin/albumin molar ratio was >0.5 in all, in the absence of
displacing drugs. All failed to pass bedside hearing screen tests and had
severe hearing loss on auditory brain response testing. Symmetrical
homogeneous hyperechogenicity of globus pallidus was the alerting feature
in 1 infant. Globus pallidus was hyperintense on T1-weighted MR images in
this child. The other infants presented with severe developmental delay as
a result of dyskinetic quadriplegia and hearing loss. Globus pallidus was
normal on T1- but hyperintense on T2-weighted MR images at 12
‘Like the stranger at a funeral who cries more than the bereaved’: ethical dilemmas in ethnographic research with children
This article contributes to debates on the practicality and utility of prior ethical review in ethnography and qualitative research using an ethnography of children’s involvement in artisanal gold mining work in Ghana as a case study. Reflecting on dilemmas and obstacles encountered in attempts to employ prescribed institutional ethical guidance modelled for childhood research in the UK during the fieldwork, the discussion brings to attention some of the problems that can arise when ethical guidance is not anchored in the lived realities or value systems of the setting in which fieldwork is conducted. The article seeks to rejuvenate calls for more flexible and socio-culturally responsive ethical review and practice as an alternative to the prescriptive ethical regimes
Selection at a single locus leads to widespread expansion of toxoplasma gondii lineages that are virulent in mice
The determinants of virulence are rarely defined for eukaryotic parasites such as T. gondii, a widespread parasite of mammals that also infects humans, sometimes with serious consequences. Recent laboratory studies have established that variation in a single secreted protein, a serine/threonine kinase known as ROPO18, controls whether or not mice survive infection. Here, we establish the extent and nature of variation in ROP18among a collection of parasite strains from geographically diverse regions. Compared to other genes, ROP18 showed extremely high levels of diversification and changes in expression level, which correlated with severity of infection in mice. Comparison with an out-group demonstrated that changes in the upstream region that regulates expression of ROP18 led to an historical increase in the expression and exposed the protein to diversifying selective pressure. Surprisingly, only three atypically distinct protein variants exist despite marked genetic divergence elsewhere in the genome. These three forms of ROP18 are likely adaptations for different niches in nature, and they confer markedly different virulence to mice. The widespread distribution of a single mouse-virulent allele among geographically and genetically disparate parasites may have consequences for transmission and disease in other hosts, including humans
ISLES 2016 and 2017-Benchmarking ischemic stroke lesion outcome prediction based on multispectral MRI
Performance of models highly depend not only on the used algorithm but also the data set it was applied to. This makes the comparison of newly developed tools to previously published approaches difficult. Either researchers need to implement others' algorithms first, to establish an adequate benchmark on their data, or a direct comparison of new and old techniques is infeasible. The Ischemic Stroke Lesion Segmentation (ISLES) challenge, which has ran now consecutively for 3 years, aims to address this problem of comparability. ISLES 2016 and 2017 focused on lesion outcome prediction after ischemic stroke: By providing a uniformly pre-processed data set, researchers from all over the world could apply their algorithm directly. A total of nine teams participated in ISLES 2015, and 15 teams participated in ISLES 2016. Their performance was evaluated in a fair and transparent way to identify the state-of-the-art among all submissions. Top ranked teams almost always employed deep learning tools, which were predominately convolutional neural networks (CNNs). Despite the great efforts, lesion outcome prediction persists challenging. The annotated data set remains publicly available and new approaches can be compared directly via the online evaluation system, serving as a continuing benchmark (www.isles-challenge.org).Fundacao para a Ciencia e Tecnologia (FCT), Portugal (scholarship number PD/BD/113968/2015). FCT with the UID/EEA/04436/2013, by FEDER funds through COMPETE 2020, POCI-01-0145-FEDER-006941. NIH Blueprint for Neuroscience Research (T90DA022759/R90DA023427) and the National Institute of Biomedical Imaging and Bioengineering (NIBIB) of the National Institutes of Health under award number 5T32EB1680. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. PAC-PRECISE-LISBOA-01-0145-FEDER-016394. FEDER-POR Lisboa 2020-Programa Operacional Regional de Lisboa PORTUGAL 2020 and Fundacao para a Ciencia e a Tecnologia. GPU computing resources provided by the MGH and BWH Center for Clinical Data Science Graduate School for Computing in Medicine and Life Sciences funded by Germany's Excellence Initiative [DFG GSC 235/2]. National Research National Research Foundation of Korea (NRF) MSIT, NRF-2016R1C1B1012002, MSIT, No. 2014R1A4A1007895, NRF-2017R1A2B4008956 Swiss National Science Foundation-DACH 320030L_163363
A Robust Ensemble Algorithm for Ischemic Stroke Lesion Segmentation: Generalizability and Clinical Utility Beyond the ISLES Challenge
Diffusion-weighted MRI (DWI) is essential for stroke diagnosis, treatment
decisions, and prognosis. However, image and disease variability hinder the
development of generalizable AI algorithms with clinical value. We address this
gap by presenting a novel ensemble algorithm derived from the 2022 Ischemic
Stroke Lesion Segmentation (ISLES) challenge. ISLES'22 provided 400 patient
scans with ischemic stroke from various medical centers, facilitating the
development of a wide range of cutting-edge segmentation algorithms by the
research community. Through collaboration with leading teams, we combined
top-performing algorithms into an ensemble model that overcomes the limitations
of individual solutions. Our ensemble model achieved superior ischemic lesion
detection and segmentation accuracy on our internal test set compared to
individual algorithms. This accuracy generalized well across diverse image and
disease variables. Furthermore, the model excelled in extracting clinical
biomarkers. Notably, in a Turing-like test, neuroradiologists consistently
preferred the algorithm's segmentations over manual expert efforts,
highlighting increased comprehensiveness and precision. Validation using a
real-world external dataset (N=1686) confirmed the model's generalizability.
The algorithm's outputs also demonstrated strong correlations with clinical
scores (admission NIHSS and 90-day mRS) on par with or exceeding expert-derived
results, underlining its clinical relevance. This study offers two key
findings. First, we present an ensemble algorithm
(https://github.com/Tabrisrei/ISLES22_Ensemble) that detects and segments
ischemic stroke lesions on DWI across diverse scenarios on par with expert
(neuro)radiologists. Second, we show the potential for biomedical challenge
outputs to extend beyond the challenge's initial objectives, demonstrating
their real-world clinical applicability
Pratos e mais pratos: louças domésticas, divisões culturais e limites sociais no Rio de Janeiro, século XIX
Reply to ten comments on a paper published in the last issue of this journal. The discussion follows along six main lines: History museums, identity, ideology and the category of nation; the need of material collections and their modalities: patrimonial, operational, virtual; theater versus laboratory; visitors and their ambiguities; Public History: the museum and the academy.Resposta aos comentários de dez especialistas que contribuíram no debate de texto publicado no último número desta revista. A discussão orientou-se segundo seis tópicos principais: museus históricos, identidade, ideologia e a categoria de nação; a necessidade de acervos materiais e suas modalidades: acervo patrimonial, operacional, virtual; teatro versus laboratório; o público e suas ambigüidades; História Pública: o museu e a Academia