Fabrication and testing of microfluidic devices for blood cell separation

This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.Blood separation is a strategic preliminary step in preparation to on-chip biological analysis. Two microfluidic devices for on-chip blood separation are presented. Both devices will be integrated to form the separation module of a Lab on Chip for non-invasive prenatal diagnosis. In the first device, a blood plasma separator, the separation of blood cells from plasma is made possible in microchannels by bio-physical effects such as an axial migration effect and Zweifach-Fung bifurcation law. Behaviour of mussel and human blood suspensions were studied alongside the effect of different geometries. The second device aims to separate fetal nucleated red blood cells based on their magnetic susceptibility. Biocompatible materials are used in the manufacturing of both devices.The authors acknowledge the financial support of the Engineering and Physical Science Research Council (EPSRC) through the funding of the Grand Challenge Project ‘3DMintegration’, reference EP/C534212/1. This work has also been supported by the EPSRC through a Doctoral Training Account (DTA) and has been performed at the Microsystems Engineering Centre (MISEC), Heriot-Watt University, Edinburgh. We thank Tim Ryan and Phil Summersgill, Epigem Ltd. for the fabrication of the blood plasma chips. The fabrication work was carried out in the Fluence Microfluidics Application Centre supported by the DTI and the OneNE Regional Development Agency as part of the UK's MNT Network

Molecular Study of Glycoprotein (G) Gene Region of Rabies Virus from Spotted Deer, Delhi, India

Rabies is a viral zoonotic disease of public health importance in India. The disease is usually transmitted by a rabid animal bite, scratches and licks on broken skin and mucous membrane. Rabies is reported from all continents except Antarctica although prevalence is more in Asia and Africa. India is endemic for rabies virus (RABV) throughout the country except for islands of Lakshadweep, Andaman & Nicobar. In the present study, brain samples of clinically suspected animals obtained during the RABV outbreak at National Zoological Park, New Delhi, India, in 2016 were initially tested for rabies antigen by DFAT. All the 32 DFAT positive brain samples were then processed for RNA isolation. The extracted RNA was amplified for glycoprotein (G) gene of 590 bp by RT-PCR followed by nucleotide sequencing. Nucleotide alignment revealed only substitutions without any insertion or deletion. Amino acid alignment revealed replacement at four positions namely L244I, T264A, M310I and N375K. The amino acid change at position where Leucine is replaced by Isoleucine has not been observed in available RABV references of the G gene region either from India or other countries. This mutation was observed in all the samples included in the present study. A phylogenetic tree showed that all the study sequences belonged to Arctic like 1a lineage, in RABV genotype 1. In conclusion, RABV in the study region is acquiring genetic variation; which may have effect on the pathogenicity. This indicates that continued molecular surveillance of the circulating rabies virus strains should be carried out

Evaluation of Direct Rapid Immunohistochemistry Test (DRIT) for Postmortem Diagnosis of Rabies

Direct fluorescent antibody test (DFAT) is considered as the gold standard for diagnosis of rabies in infected mammals as it has high sensitivity and specificity. However, high cost and technical demand limits its utilization, particularly in developing countries including India. Therefore, in this study we evaluated recently developed direct rapid immunohistochemistry test (DRIT) for diagnosis of rabies in comparison with the DFAT. A total of 109 brain samples received during the period of 6 years from different regions of India were tested following standard protocol. The results showed 100% correlation between the two tests.

Can Computer-Assisted Training of Prerequisite Motor Skills Help Enable Communication in People with Autism?

Our and others' research indicates that in fully a third of people with autism who lack communicative speech, the communication deficit may actually be a deficit in motor skills necessary to move the mouth and the vocal tract. These individuals have difficulties in fine, gross and especially oral motor skills, and a disparity between impaired expressive language and relatively intact receptive language: that is to say, they can listen but not speak. Because involvement in research and receipt of the fullest educational, occupational and other services demands ability to interact verbally and to control one's movements and actions, these people get the short end of the stick when it comes to scientific enquiry and pedagogic and therapeutic practice. Point OutWords, tablet-based software designed in collaboration with autistic clients and their communication therapists, exploits the autistic fascination with parts and details to motivate attention to learning manual motor and oral motor skills essential for communication. Along the way, autistic clients practise pointing and dragging at objects, then pointing at sequences of letters on a keyboard, and even speaking the syllables represented by these letters. Whereas many teaching and learning strategies adapted from methods for non-autistic people end up working against autistic cognition by asking people with autism to do what they cannot easily do, Point OutWords works with autistic cognition, by beginning from the autistic skill at manipulating parts and details. Users and their parents or guardians can opt into collection of data on motor interactions with Point OutWords; these internal measures of motor skills development are complemented by external, standardised tests of motor, oral motor and communicative development. These quantitative measures are collected alongside reports on Point OutWords's acceptability to users, and users' fidelity to a recommended treatment regime, so as to evaluate feasibility of a larger randomised controlled trial

Rate of complete spectacle independence with a trifocal intraocular lens: a systematic literature review and meta-analysis

Introduction A systematic literature review and meta-analysis was conducted to identify and obtain a precise single summary estimate on complete spectacle independence after bilateral implantation of a trifocal intraocular lens (IOL) (AcrySof PanOptix, TFNTXX/TFATXX) for patients undergoing cataract surgery. Methods A search was conducted in PubMed from January 2017 to September 2021. Relevant congress presentations were also searched to include data from completed studies not yet published. Search terms included the intervention (TFNTXX, TFATXX, PanOptix) and outcomes of interest (patient-reported spectacle independence rates). A Bayesian random-effects meta-analysis was conducted, providing a pooled estimate (median and its 95% credible interval) of complete spectacle independence rates among cataract surgery patients. Subgroup analyses evaluated spectacle independence after cataract surgery across different working distances (near, intermediate, far). Results Nineteen unique clinical studies were identified. Based on a meta-analysis of 13 studies (N = 513 patients), the complete spectacle independence rate after cataract surgery with TFNTXX/TFATXX IOL was 91.6% (95% credible interval 86.8–95.9%). Additionally, the spectacle independence rates at each focal point (N = 13 studies, 603 patients) were 89.6% (near), 96.3% (intermediate), and 95.9% (far). Conclusions This meta-analysis demonstrated that at least nine out of ten patients receiving TFNTXX/TFATXX trifocal IOL during cataract surgery can expect to achieve complete spectacle independence. This study provides informative data for clinicians and patients to feel confident in the use of trifocal intraocular lenses as presbyopia-correcting IOLs that offer high rates of complete spectacle independence

RSV-specific airway resident memory CD8+ T cells and differential disease severity after experimental human infection

In animal models, resident memory CD8+ T (Trm) cells assist in respiratory virus elimination but their importance in man has not been determined. Here, using experimental human respiratory syncytial virus (RSV) infection, we investigate systemic and local virus-specific CD8+ T cell responses in adult volunteers. Having defined the immunodominance hierarchy, we analyze phenotype and function longitudinally in blood and by serial bronchoscopy. Despite rapid clinical recovery, we note surprisingly extensive lower airway inflammation with persistent viral antigen and cellular infiltrates. Pulmonary virus-specific CD8+ T cells display a CD69+CD103+ Trm phenotype and accumulate to strikingly high frequencies into convalescence without continued proliferation. These are more highly differentiated but express fewer cytotoxicity markers than in blood, but their abundance prior to infection correlates with protection from more severe disease

Distribution of preoperative and postoperative astigmatism in a large population of patients undergoing cataract surgery in the UK

PURPOSE: To assess the prevalence and severity of preoperative and postoperative astigmatism in patients with cataract in the UK. SETTING: Data from 8 UK National Health Service ophthalmology clinics using MediSoft electronic medical records (EMRs). DESIGN: Retrospective cohort study. METHODS: Eyes from patients aged ≥65 years undergoing cataract surgery were analysed. For all eyes, preoperative (corneal) astigmatism was evaluated using the most recent keratometry measure within 2 years prior to surgery. For eyes receiving standard monofocal intraocular lens (IOLs), postoperative refractive astigmatism was evaluated using the most recent refraction measure within 2-12 months postsurgery. A power vector analysis compared changes in the astigmatic 2-dimensional vector (J0, J45) before and after surgery, for the subgroup of eyes with both preoperative and postoperative astigmatism measurements. Visual acuity was also assessed preoperatively and postoperatively. RESULTS: Eligible eyes included in the analysis were 110 468. Of these, 78% (n=85 650) had preoperative (corneal) astigmatism ≥0.5 dioptres (D), 42% (n=46 003) ≥1.0 D, 21% (n=22 899) ≥1.5 D and 11% (n=11 651) ≥2.0 D. After surgery, the refraction cylinder was available for 39 744 (36%) eyes receiving standard monofocal IOLs, of which 90% (n=35 907) had postoperative astigmatism ≥0.5 D and 58% (n=22 886) ≥1.0 D. Visual acuity tended to worsen postoperatively with increased astigmatism (ρ=-0.44, P<0.01). CONCLUSIONS: There is a significant burden of preoperative astigmatism in the UK cataract population. The available refraction data indicate that this burden is not reduced after surgery with implantation of standard monofocal IOLs. Measures should be taken to improve visual outcomes of patients with astigmatic cataract by simultaneously correcting astigmatism during cataract surgery

Visceral leishmaniasis cyclical trends in Bihar, India – implications for the elimination programme. [version 1; referees: 1 approved, 2 approved with reservations]

Background: Visceral leishmaniasis (VL) is a vector-borne disease of public health importance in India, with the highest burden of disease in the states of Bihar, Jharkhand, West Bengal and Uttar Pradesh. The disease is currently targeted for elimination (annual incidence to less than one per 10,000 population) using indoor residual spraying, active case detection and treatment. Historically the disease trend in India has been regarded as cyclical with case resurgence characteristically occurring every 15 years.  Understanding this pattern is essential if the VL elimination gains are to be sustained. To better understand the cyclical trends, annual climatic indicators including rainfall, temperature and humidity over time were compared with annual VL case incidence data.  Methods: Annual climate data (rainfall, average and maximum temperature and specific humidity) from 1956-2004 were used to identify potential factors influencing VL incidence.  Months relevant to the VL life-cycle were identified and defined (Monsoon, Sand-fly Peak, Pre-Sand-fly Peak and Annual) for analysis. The Kruskall-Wallis test was used to determine significant difference between categorical rainfall and VL incidence, whilst univariate negative binomial regression models were used to determine predictors of disease incidence. Results: The negative binomial regression model showed statistically significant associations (p 0.05).  Conclusion: The VL programme in Bihar has made significant progress in adopting best practices for improved treatment and vector control, with the aim to achieve VL elimination.  However, open access granular programme data for indoor residual spray activities and case detection is required to fully understand the role of climate in disease transmission and potential resurgence

A tablet computer-assisted motor and language skills training programme to promote communication development in children with autism: development and pilot study

Autism is a heterogenous condition, encompassing many different subtypes and presentations. Of those people with autism who lack communicative speech, some are more skilled at receptive language than their expressive difficulty might suggest. This disparity between what can be spoken and what can be understood correlates with motor and especially oral motor abilities, and thus may be a consequence of limits to oral motor skill. Point OutWords, tablet-based software targeted for this subgroup, builds on autistic perceptual and cognitive strengths to develop manual motor and oral motor skills prerequisite to communication by pointing or speaking. Although typical implementations of user-centred design rely on communicative speech, Point OutWords users were involved as co-creators both directly via their own nonverbal behavioural choices and indirectly via their communication therapists’ reports; resulting features include vectorised, high-contrast graphics, exogenous cues to help capture and maintain attention, customisable reinforcement prompts, and accommodation of open-loop visuomotor control