261 research outputs found
Overall Survival Time Prediction for High-grade Glioma Patients based on Large-scale Brain Functional Networks
High-grade glioma (HGG) is a lethal cancer with poor outcome. Accurate preoperative overall survival (OS) time prediction for HGG patients is crucial for treatment planning. Traditional presurgical and noninvasive OS prediction studies have used radiomics features at the local lesion area based on the magnetic resonance images (MRI). However, the highly complex lesion MRI appearance may have large individual variability, which could impede accurate individualized OS prediction. In this paper, we propose a novel concept, namely brain connectomics-based OS prediction. It is based on presurgical resting-state functional MRI (rs-fMRI) and the non-local, large-scale brain functional networks where the global and systemic prognostic features rather than the local lesion appearance are used to predict OS. We propose that the connectomics features could capture tumor-induced network-level alterations that are associated with prognosis. We construct both low-order (by means of sparse representation with regional rs-fMRI signals) and high-order functional connectivity (FC) networks (characterizing more complex multi-regional relationship by synchronized dynamics FC time courses). Then, we conduct a graph-theoretic analysis on both networks for a jointly, machine-learning-based individualized OS prediction. Based on a preliminary dataset (N = 34 with bad OS, mean OS, ~400 days; N = 34 with good OS, mean OS, ~1030 days), we achieve a promising OS prediction accuracy (86.8%) on separating the individuals with bad OS from those with good OS. However, if using only conventionally derived descriptive features (e.g., age and tumor characteristics), the accuracy is low (63.2%). Our study highlights the importance of the rs-fMRI and brain functional connectomics for treatment planning
Motor coordination problems in children and adolescents with ADHD rated by parents and teachers: effects of age and gender
Summary.
Objective. ADHD is frequently accompanied by motor coordination problems. However, the co-occurrence of poor motor performance has
received less attention in research than other coexisting problems in ADHD. The underlying mechanisms of this association
remain unclear. Therefore, we investigated the prevalence of motor coordination problems in a large sample of children with
ADHD, and the relationship between motor coordination problems and inattentive and hyperactive/impulsive symptoms. Furthermore,
we assessed whether the association between ADHD and motor coordination problems was comparable across ages and was similar
for both genders.
Method. We investigated 486 children with ADHD and 269 normal controls. Motor coordination problems were rated by parents (Developmental
Coordination Disorder Questionnaire) and teachers (Groningen Motor Observation Scale).
Results. Parents and teachers reported motor coordination problems in about one third of children with ADHD. Problems of fine and
gross motor skills, coordination skills and motor control were all related to inattentive rather than hyperactive/impulsive
symptoms. Relative to controls, motor coordination problems in ADHD were still present in teenagers according to parents;
the prevalence diminished somewhat according to teachers. Boys and girls with ADHD were comparably affected, but motor performance
in controls was better in girls than in boys.
Conclusions. Motor coordination problems were reported in one third of children with ADHD and affected both boys and girls. These problems
were also apparent in adolescents with ADHD. Clinicians treating children with ADHD should pay attention to co-occurring motor
coordination problems because of the high prevalence and the negative impact of motor coordination problems on daily life
Syntactic Network Analysis in Schizophrenia-Spectrum Disorders
BACKGROUND: Language anomalies are a hallmark feature of schizophrenia-spectrum disorders (SSD). Here, we used network analysis to examine possible differences in syntactic relations between patients with SSD and healthy controls. Moreover, we assessed their relationship with sociodemographic factors, psychotic symptoms, and cognitive functioning, and we evaluated whether the quantification of syntactic network measures has diagnostic value. STUDY DESIGN: Using a semi-structured interview, we collected speech samples from 63 patients with SSD and 63 controls. Per sentence, a syntactic representation (ie, parse tree) was obtained and used as input for network analysis. The resulting syntactic networks were analyzed for 11 local and global network measures, which were compared between groups using multivariate analysis of covariance, considering the effects of age, sex, and education. RESULTS: Patients with SSD and controls significantly differed on most syntactic network measures. Sex had a significant effect on syntactic measures, and there was a significant interaction between sex and group, as the anomalies in syntactic relations were most pronounced in women with SSD. Syntactic measures were correlated with negative symptoms (Positive and Negative Syndrome Scale) and cognition (Brief Assessment of Cognition in Schizophrenia). A random forest classifier based on the best set of network features distinguished patients from controls with 74% cross-validated accuracy. CONCLUSIONS: Examining syntactic relations from a network perspective revealed robust differences between patients with SSD and healthy controls, especially in women. Our results support the validity of linguistic network analysis in SSD and have the potential to be used in combination with other automated language measures as a marker for SSD.</p
A role for human leucocyte antigens in the susceptibility to SARS‐Cov‐2 infection observed in transplant patients
We analysed data from 80 patients who tested positive for SARS‐CoV‐2 RNA who had previously been HLA typed to support transplantation. Data were combined from two adjacent centres in Manchester and Leeds to achieve a sufficient number for early analysis. HLA frequencies observed were compared against two control populations: first, against published frequencies in a UK deceased donor population (n = 10,000) representing the target population of the virus, and second, using a cohort of individuals from the combined transplant waiting lists of both centres (n = 308), representing a comparator group of unaffected individuals of the same demographic. We report a significant HLA association with HLA‐ DQB1*06 (53% vs. 36%; p < .012; OR 1.96; 95% CI 1.94–3.22) and infection. A bias towards an increased representation of HLA‐A*26, HLA‐DRB1*15, HLA‐DRB1*10 and DRB1*11 was also noted but these were either only significant using the UK donor controls, or did not remain significant after correction for multiple tests. Likewise, HLA‐A*02, HLA‐B*44 and HLA‐C*05 may exert a protective effect, but these associations did not remain significant after correction for multiple tests. This is relevant information for the clinical management of patients in the setting of the current SARS‐CoV‐2 pandemic and potentially in risk‐assessing staff interactions with infected patients
The Jacob2 Lectin of the Entamoeba histolytica Cyst Wall Binds Chitin and Is Polymorphic
For many years, we and others have used cysts of Entamoeba invadens (Ei), a reptilian parasite, to model the infectious and diagnostic cysts of the human pathogen Entamoeba histolytica (Eh). The Ei cyst wall is composed of chitin fibrils, as well as Jacob and Jessie lectins that have unique chitin-binding domains. Our recent results suggest a “wattle and daub” model of the Ei cyst wall, where the wattle or sticks (chitin fibrils bound by multivalent Jacob lectins) is constructed prior to the addition of the mortar or daub (self-aggregating Jessie3 lectins). Here we “humanize” the Ei model of the cyst wall with four findings. First, a recombinant Eh Jacob2 lectin, which has three predicted chitin-binding domains surrounding a large spacer domain, binds chitin beads. Second, polymorphisms in the spacer domain of EhJacob2 discriminate clinical isolates of Entamoeba. Third, chitinase, Jacob2 lectin, and Jessie3 lectin are present in cyst walls of clinical isolates of Entamoeba. Finally, numerous sera from patients infected with Entamoeba recognize recombinant Eh Jacob1 and Jessie3 lectins
Motion processing with wide-field neurons in the retino-tecto-rotundal pathway
The retino-tecto-rotundal pathway is the main visual pathway in non-mammalian vertebrates and has been found to be highly involved in visual processing. Despite the extensive receptive fields of tectal and rotundal wide-field neurons, pattern discrimination tasks suggest a system with high spatial resolution. In this paper, we address the problem of how global processing performed by motion-sensitive wide-field neurons can be brought into agreement with the concept of a local analysis of visual stimuli. As a solution to this problem, we propose a firing-rate model of the retino-tecto-rotundal pathway which describes how spatiotemporal information can be organized and retained by tectal and rotundal wide-field neurons while processing Fourier-based motion in absence of periodic receptive-field structures. The model incorporates anatomical and electrophysiological experimental data on tectal and rotundal neurons, and the basic response characteristics of tectal and rotundal neurons to moving stimuli are captured by the model cells. We show that local velocity estimates may be derived from rotundal-cell responses via superposition in a subsequent processing step. Experimentally testable predictions which are both specific and characteristic to the model are provided. Thus, a conclusive explanation can be given of how the retino-tecto-rotundal pathway enables the animal to detect and localize moving objects or to estimate its self-motion parameters
A Local Algorithm for the Computation of Image Velocity via Constructive Interference of Global Fourier Components
Evidence for a “Wattle and Daub” Model of the Cyst Wall of Entamoeba
The cyst wall of Entamoeba invadens (Ei), a model for the human pathogen Entamoeba histolytica, is composed of fibrils of chitin and three chitin-binding lectins called Jacob, Jessie3, and chitinase. Here we show chitin, which was detected with wheat germ agglutinin, is made in secretory vesicles prior to its deposition on the surface of encysting Ei. Jacob lectins, which have tandemly arrayed chitin-binding domains (CBDs), and chitinase, which has an N-terminal CBD, were each made early during encystation. These results are consistent with their hypothesized roles in cross-linking chitin fibrils (Jacob lectins) and remodeling the cyst wall (chitinase). Jessie3 lectins likely form the mortar or daub of the cyst wall, because 1) Jessie lectins were made late during encystation; 2) the addition to Jessie lectins to the cyst wall correlated with a marked decrease in the permeability of cysts to nucleic acid stains (DAPI) and actin-binding heptapeptide (phalloidin); and 3) recombinant Jessie lectins, expressed as a maltose-binding proteins in the periplasm of Escherichia coli, caused transformed bacteria to agglutinate in suspension and form a hard pellet that did not dissociate after centrifugation. Jessie3 appeared as linear forms and rosettes by negative staining of secreted recombinant proteins. These findings provide evidence for a “wattle and daub” model of the Entamoeba cyst wall, where the wattle or sticks (chitin fibrils likely cross-linked by Jacob lectins) is constructed prior to the addition of the mortar or daub (Jessie3 lectins)
British Transplantation Society guidelines on abdominal organ transplantation from deceased donors after circulatory death
\ua9 2023 The Author(s). The British Transplantation Society (BTS) ‘Guideline on transplantation from deceased donors after circulatory death’ has recently been updated and this manuscript summarises the relevant recommendations in abdominal organ transplantation from Donation after Circulatory Death (DCD) donors, encompassing the chapters on liver, kidney, pancreas and islet cell transplantation
Erratum to The impact of time to death in donors after circulatory death on recipient outcome in simultaneous pancreas-kidney transplantation [American Journal of Transplantation 24 (2024) 1247–1256, (S1600613524001345), (10.1016/j.ajt.2024.02.008)]
\ua9 2024 The Author(s). The publisher regrets that the published article included errors in the layout of Table 1. The full and correct Table 1 is given here. [Table presented] The publisher would like to apologise for any inconvenience caused
- …
