Intra-orbital distance as a record of social brain dysmorphology in autism

Minor Physical Anomalies (MPAs) arise during the first trimester of prenatal life and occur more frequently in autism and related neurodevelopmental disorders. We measured intra-orbital distances from T1 weighted images of children with autism aged 6 – 16 years and typically developing peers. We report a significant increase in intra-orbital distance in autism. Using voxel-wise linear regression analysis intra-orbital distances were found to positively correlate with the volume of inferio-temporal regions including the amygdala in the autism group only. We suggest that intra-orbital MPA may provide a ‘fossil’ record of much earlier childhood brain expansion in autism.published_or_final_versionThe 19th Annual Meeting of the International Society for Magnetic Resonance in Medicine (ISMRM), Montreal, Canada, 7-13 May 2011. In Proceedings of the 19th ISMRM, 2011, p. 252

The effects of stent porosity on the endovascular treatment of intracranial aneurysms located near a bifurcation

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Computational fluid dynamics study of bifurcation aneurysms treated with pipeline embolization device: side branch diameter study

An intracranial aneurysm, abnormal swelling of the cerebral artery, may lead to undesirable rates of mortality and morbidity upon rupture. Endovascular treatment involves the deployment of a flow-diverting stent that covers the aneurysm orifice, thereby reducing the blood flow into the aneurysm and mitigating the risk of rupture. In this study, computational fluid dynamics analysis is performed on a bifurcation model to investigate the change in hemodynamics with various side branch diameters. The condition after the deployment of a pipeline embolization device is also simulated. Hemodynamic factors such as flow velocity, pressure, and wall shear stress are studied. Aneurysms with a larger side branch vessel might have greater risk after treatment in terms of hemodynamics. Although a stent could lead to flow reduction entering the aneurysm, it would drastically alter the flow rate inside the side branch vessel. This may result in side-branch hypoperfusion subsequent to stenting. In addition, two patient-specific bifurcation aneurysms are tested, and the results show good agreement with the idealized models. Furthermore, the peripheral resistance of downstream vessels is investigated by varying the outlet pressure conditions. This quantitative analysis can assist in treatment planning and therapeutic decision-making.published_or_final_versio

Patient Perception of Physician Attire Before and After Disclosure of the Risks of Microbial Contamination

Background: The white coat is traditionally considered to be the appropriate attire for physicians but it may also be contaminated with microbes and act as a potential source of infection. We aimed to study patients’ acceptance of physicians’ attire, their underlying reasons, and their reactions to an educational intervention with regards to the risks of contamination. Methods: We conducted a voluntary questionnaire survey at a university teaching hospital in Hong Kong from February to July 2012. 262 patient-responses from adult inpatients and outpatients across various specialties were analysed. Results: White coats were highly favoured (90.8%) when compared with scrubs (22.1%), smart casual (7.6%) and formal (7.3%) wears. ’Professional image’ and ‘ease of identification’ were the main attributes of the white coat. Most patients (92.2%) would prefer doctors washing their white coats every few days, whilst 80.9% believed that doctors were actually doing so. After patients were informed of the potential risk of microbial contamination, white coats remained as the most favoured attire (66.4%), but with scrubs doubling in popularity (45.8%). Smart casual (9.2%) and formal attire (4.6%) remain the least accepted. Conclusion: Despite cross-infections being a significant concern within the healthcare environments, patients’ predominant acceptance and perceived attributes towards the white coat were maintained after an educational intervention on the risks of microbial contamination.published_or_final_versio

Copy number variation analysis based on AluScan sequences

BACKGROUND: AluScan combines inter-Alu PCR using multiple Alu-based primers with opposite orientations and next-generation sequencing to capture a huge number of Alu-proximal genomic sequences for investigation. Its requirement of only sub-microgram quantities of DNA facilitates the examination of large numbers of samples. However, the special features of AluScan data rendered difficult the calling of copy number variation (CNV) directly using the calling algorithms designed for whole genome sequencing (WGS) or exome sequencing. RESULTS: In this study, an AluScanCNV package has been assembled for efficient CNV calling from AluScan sequencing data employing a Geary-Hinkley transformation (GHT) of read-depth ratios between either paired test-control samples, or between test samples and a reference template constructed from reference samples, to call the localized CNVs, followed by use of a GISTIC-like algorithm to identify recurrent CNVs and circular binary segmentation (CBS) to reveal large extended CNVs. To evaluate the utility of CNVs called from AluScan data, the AluScans from 23 non-cancer and 38 cancer genomes were analyzed in this study. The glioma samples analyzed yielded the familiar extended copy-number losses on chromosomes 1p and 9. Also, the recurrent somatic CNVs identified from liver cancer samples were similar to those reported for liver cancer WGS with respect to a striking enrichment of copy-number gains in chromosomes 1q and 8q. When localized or recurrent CNV-features capable of distinguishing between liver and non-liver cancer samples were selected by correlation-based machine learning, a highly accurate separation of the liver and non-liver cancer classes was attained. CONCLUSIONS: The results obtained from non-cancer and cancerous tissues indicated that the AluScanCNV package can be employed to call localized, recurrent and extended CNVs from AluScan sequences. Moreover, both the localized and recurrent CNVs identified by this method could be subjected to machine-learning selection to yield distinguishing CNV-features that were capable of separating between liver cancers and other types of cancers. Since the method is applicable to any human DNA sample with or without the availability of a paired control, it can also be employed to analyze the constitutional CNVs of individuals.published_or_final_versio

The smiley as a simple screening tool for depression after stroke: A preliminary study

In Hong Kong, there is a paucity of evidence to support which tool is superior in measuring depression after stroke (DAS). A simple, non-language-based, culturally neutral, non-verbal and easy to apply tool that is not highly dependent on training will be desirable. Objectives: The present study aimed to examine the clinical utility of three smiley pictures in detecting DAS for older Chinese patients at 1 month after first-ever ischemic stroke. Methods: This was a cross-sectional study. A total of 253 stroke patients were interviewed by a research nurse at 1-month follow-up. Results: Taking Diagnostic and Statistic Manual (DSM IV) as the gold standard, the measurement properties of emoticon (sad) in terms of sensitivity, specificity, positive and negative predictive values, as well as Kappa's value were found comparable to Geriatric Depression Scale (GDS). The emoticon (happy) demonstrated a highly significant inverse relationship with all depression assessment tools (p<0.001). It was also found that the emoticon (flat) could capture 98% of all depressed subjects identified by DSM IV, although its predictive values were less satisfactory. Conclusions: The smiley pictures seemed to fulfil the requirements for early and prompt screening among older patients. Cultural implication regarding emotions dissipation among Chinese patients should be further studied. © 2007 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

Incidence and predictors of depression after stroke (DAS)

Objective. Depression after stroke (DAS) poses a treble burden to patients, families and health care system. The purpose of this paper is to estimate the incidence of depression among first-ever ischemic stroke patients and identify the predictors of DAS. Methods. A longitudinal study design was undertaken. Of 836 patients admitted to the stroke unit of two regional hospitals in Hong Kong during the period 1 June 2004 to 31 May 2005, 295 patients fulfilled the inclusion and exclusion criteria. A total of 260 patients had given their consents and were interviewed at 1 month after stroke onset. Results. Nearly one-quarter of the first ischemic stroke patients, who were known to be free of personal and family history of psychiatric illnesses, were found to satisfy the criteria of depression using Diagnostic and Statistical Manual IV (24%, 48 out of 200 participants; 95% CI: 18.6%, 30.4%). This result was close to that assessed by the Geriatric Depression Scale (GDS) - 15 items. The psycho-emotional factor and level of dependency were found to be most significant predictors for DAS onset. Conclusion. The high incidence of DAS and low rate of accessibility to treatment indicate timely action to be undertaken. © 2007 Taylor & Francis.link_to_subscribed_fulltex