Clozapine-induced liver injury and pleural effusion

Clozapine, whilst associated commonly with a transient and benign increase in liver enzymes, has also been associated with varying presentations of hepatitis in existing case reports. This report describes what we believe to be the first documented case of acute liver injury and pleural effusion associated with clozapine, resolving after cessation of the agent. The case supports existing literature in advocating a high index of suspicion, particularly in the 4-5 weeks following clozapine initiation, when considering nonspecific clinical symptoms and signs.

Proactive Relay Selection with Joint Impact of Hardware Impairment and Co-channel Interference

In this paper, we investigate the end-to-end performance of dual-hop proactive decode-and-forward relaying networks with Nth best relay selection in the presence of two practical deleterious effects: i) hardware impairment and ii) cochannel interference. In particular, we derive new exact and asymptotic closed-form expressions for the outage probability and average channel capacity of Nth best partial and opportunistic relay selection schemes over Rayleigh fading channels. Insightful discussions are provided. It is shown that, when the system cannot select the best relay for cooperation, the partial relay selection scheme outperforms the opportunistic method under the impact of the same co-channel interference (CCI). In addition, without CCI but under the effect of hardware impairment, it is shown that both selection strategies have the same asymptotic channel capacity. Monte Carlo simulations are presented to corroborate our analysis.

Bladder continence management in adult acquired brain injury

Purpose: Persistence of urinary incontinence post acquired brain injury (ABI) carries important prognostic significance. We undertook to document the incidence of urinary incontinence, its management and complications in rehabilitation inpatients following ABI and to assess adherence to post ABI bladder management guidelines. 

Method: A retrospective chart survey of a convenience sample of consecutive admissions to two adult neurorehabilitation units Forster Green Hospital, Belfast, and the Scottish Brain Injury Rehabilitation Service, Edinburgh (SBIRSE). Bladder continence and management on transfer to and discharge from rehabilitation, trial removal of catheter, use of bladder drill, ultrasound investigation, anticholinergic medication and complications were recorded. 

Results: One hundred and forty six patients were identified. Seventy-seven (52.7%) were independent and continent of urine at rehabilitation admission and 109 (74.7%) on discharge. In all, 13 patients had urinary tract infection, 7 had urethral stricture and 1 developed haematuria whilst catheterised. Ultrasound of renal tracts was underused. Trial removal of catheter after transfer to rehabilitation occurred at a median of 10 days. 

Conclusions: Urinary continence was achieved in almost half of incontinent ABI patients during rehabilitation. There is potential for increased use of investigation of the renal tracts. Rehabilitation physicians should consider urethral stricture in the management of continence post ABI. 

Implications for Rehabilitation:

- Persisting urinary incontinence post ABI is associated with increased morbidity.

- Urethral stricture is an under-recognised complication after ABI and should be considered as a potential cause of incontinence in this patient group.

- Gains in urinary continence are seen in patients post ABI, managed with various interventions.

- Goal setting offers an opportunity to focus on bladder management rather than simply continence and may allow improvement in rate of appropriate investigation

Inhibition of Rho-kinase protects cerebral barrier from ischaemia-evoked injury through modulations of endothelial cell oxidative stress and tight junctions

Ischaemic strokes evoke blood-brain barrier (BBB) disruption and oedema formation through a series of mechanisms involving Rho-kinase activation. Using an animal model of human focal cerebral ischaemia, this study assessed and confirmed the therapeutic potential of Rho-kinase inhibition during the acute phase of stroke by displaying significantly improved functional outcome and reduced cerebral lesion and oedema volumes in fasudil- versus vehicle-treated animals. Analyses of ipsilateral and contralateral brain samples obtained from mice treated with vehicle or fasudil at the onset of reperfusion plus 4 h post-ischaemia or 4 h post-ischaemia alone revealed these benefits to be independent of changes in the activity and expressions of oxidative stress- and tight junction-related parameters. However, closer scrutiny of the same parameters in brain microvascular endothelial cells subjected to oxygen-glucose deprivation ± reperfusion revealed marked increases in prooxidant NADPH oxidase enzyme activity, superoxide anion release and in expressions of antioxidant enzyme catalase and tight junction protein claudin-5. Cotreatment of cells with Y-27632 prevented all of these changes and protected in vitro barrier integrity and function. These findings suggest that inhibition of Rho-kinase after acute ischaemic attacks improves cerebral integrity and function through regulation of endothelial cell oxidative stress and reorganization of intercellular junctions. Inhibition of Rho-kinase (ROCK) activity in a mouse model of human ischaemic stroke significantly improved functional outcome while reducing cerebral lesion and oedema volumes compared to vehicle-treated counterparts. Studies conducted with brain microvascular endothelial cells exposed to OGD ± R in the presence of Y-27632 revealed restoration of intercellular junctions and suppression of prooxidant NADPH oxidase activity as important factors in ROCK inhibition-mediated BBB protection.

Interpretable semantic vectors from a joint model of brain-and text-based meaning

Vector space models (VSMs) represent word meanings as points in a high dimensional space. VSMs are typically created using a large text corpora, and so represent word semantics as observed in text. We present a new algorithm (JNNSE) that can incorporate a measure of semantics not previously used to create VSMs: brain activation data recorded while people read words. The resulting model takes advantage of the complementary strengths and weaknesses of corpus and brain activation data to give a more complete representation of semantics. Evaluations show that the model 1) matches a behavioral measure of semantics more closely, 2) can be used to predict corpus data for unseen words and 3) has predictive power that generalizes across brain imaging technologies and across subjects. We believe that the model is thus a more faithful representation of mental vocabularies.

Cross-participant modelling based on joint or disjoint feature selection: an fMRI conceptual decoding study

Multivariate classification techniques have proven to be powerful tools for distinguishing experimental conditions in single sessions of functional magnetic resonance imaging (fMRI) data. But they are vulnerable to a considerable penalty in classification accuracy when applied across sessions or participants, calling into question the degree to which fine-grained encodings are shared across subjects. Here, we introduce joint learning techniques, where feature selection is carried out using a held-out subset of a target dataset, before training a linear classifier on a source dataset. Single trials of functional MRI data from a covert property generation task are classified with regularized regression techniques to predict the semantic class of stimuli. With our selection techniques (joint ranking feature selection (JRFS) and disjoint feature selection (DJFS)), classification performance during cross-session prediction improved greatly, relative to feature selection on the source session data only. Compared with JRFS, DJFS showed significant improvements for cross-participant classification. And when using a groupwise training, DJFS approached the accuracies seen for prediction across different sessions from the same participant. Comparing several feature selection strategies, we found that a simple univariate ANOVA selection technique or a minimal searchlight (one voxel in size) is appropriate, compared with larger searchlights.

Early intervention can improve outcomes in acute kidney injury

Acute Kidney Injury(AKI) is common, costly to manage and associated with high mortality. AKI can occur either in the community or in hospitalised patients and may be challenging to recognise because it is typically asymptomatic.Opportunities for prevention of AKI are frequently missed and in the absence of symptoms or signs there is often a delay in recognition ofestablished AKI.Approximately two thirds of hospitalised patients admitted with AKI have developed AKI in the community. AKI in hospitalised patients is associated with a substantial mortality rate > 20%. AKI is a potentially reversible process so improvements in recognition and early interventions could have a major impact on patient outcomes.