133 research outputs found

    Interventions to limit the progression of myopia

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    Myopia is invariably a lifelong condition characterised by high prevalence, significant risk in terms of associated ocular pathology, due to its increased axial length, and a substantial economic and social burden. While myopia can be corrected with spectacles and standard contact lenses, neither protect the eye from continued growth nor increased progression. At birth, the eye’s refractive error can be significant. As the eye grows the magnitudeof refractive error commonly reduces in a process termed ‘emmetropisation’. Substantial evidence exists to suggest that emmetropisation is an active process which relies on a normal visual experience, the absence of which in early life typically results in a refractive error. Research from animal models has shown the peripheral retina also plays a role in the emmetropisation process. Modification of the peripheral focus has been found to influence myopia progression. This thesis is stimulated by the findings of Anstice and Phillips (2011) who, using a Dual-Focus contact lens, which provided clear central vision and simultaneous peripheral myopic retinal defocus, showed a reduction in axial myopic progression in children. This thesis aims to describe the efficacy of a parallel-group, double blind and randomised controlled trial of a dual focus contact lens to slow myopia progression in children. Biometric data were compared for 27 myopic child participants aged 8 to 12 years at baseline. Children who wore the test lens had 41% less progression of myopia as measured by cycloplegic refraction and 44.5% less axial elongation after 12 months of lens wear. Additionally, the effect of lag of accommodation, peripheral refractive error, pupil size and time spent outdoors were explored. This thesis demonstrates that peripheral retinal defocus plays a role in slowing the progression of myopia in children and that interventions to limit the progression of myopia may need to be tailored to individual characteristics

    Object orientated automated image analysis: quantitative and qualitative estimation of inflammation in mouse lung

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    Historically, histopathology evaluation is performed by a pathologist generating a qualitative assessment on thin tissue sections on glass slides. In the past decade, there has been a growing interest for tools able to reduce human subjectivity and improve workload. Whole slide scanning technology combined with object orientated image analysis can offer the capacity of generating fast and reliable results. In the present study, we combined the use of these emerging technologies to characterise a mouse model for chronic asthma. We monitored the inflammatory changes over five weeks by measuring the number of neutrophils and eosinophils present in the tissue, as well as, the bronchiolar associated lymphoid tissue (BALT) area on whole lungs sections. We showed that inflammation assessment could be automated efficiently and reliably. In comparison to human evaluation performed on the same set of sections, computer generated data was more descriptive and fully quantitative. Moreover optimisation of our detection parameters allowed us to be to more sensitive and to generate data in a larger dynamic range to traditional experimental evaluation, such as bronchiolar lavage (BAL) inflammatory cell counts obtained by flow cytometry. We also took advantage of the fact that we could increase the number of samples to be analysed within a day. Such optimisation allowed us to determine the best study design and experimental conditions in order to increase statistical significance between groups. In conclusion, we showed that combination of whole slide digital scanning and image analysis could be fully automated and deliver more descriptive and biologically relevant data over traditional methods evaluating histopathological pulmonary changes observed in this mouse model of chronic asthma

    Left Atrial scar assessment using imaging with isotropic spatial resolution and compressed sensing

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    Summary. We assess left atrial scar using late gadolinium enhancement (LGE) with isotropic spatial resolution of 1.43mm31.4^3 mm^3 by using highly accelerated LOST [1] reconstruction. Background. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia [2]. Pulmonary vein isolation (PVI) using radiofrequency (RF)-ablation is the leading treatment for AF. Recently, LGE imaging of the LA has been used to identify atrial wall scar due to RF-ablation [3]. However, current LGE methods have limited spatial resolution that substantially impact assessment of scar in the complex geometry of PVs and LA. In this study, we sought to utilize prospective random k-space sampling and LOST [1] for accelerated LGE imaging, where reduction in imaging time was traded-off for improved isotropic spatial-resolution. Methods. 23 patients with history of AF (6 females, 58.1±9.658.1 \pm 9.6 years, 9 pre-PVI, 2 with history of PVI; 8 post-PVI; 3 with both pre and post-PVI) were recruited for this study. LGE images were acquired 10-to-20 minutes after bolus infusion of 0.2 mmol/kg Gd-DTPA. Free-breathing ECG-triggered navigator-gated inversion-recovery GRE sequences were used for all acquisitions (TR/TE/α=5.2/2.6ms/25°,FOV=320×320×100mmTR/TE/ \alpha = 5.2/2.6ms/25°, FOV=320×320×100mm). The PV inflow artifact reduction technique in [4] was also utilized. For each patient, a standard non-isotropic 3D LGE scan (1.4×1.4×4.0mm31.4×1.4×4.0mm^3) and a 3-fold-accelerated highresolution 3D LGE scan (1.43mm31.4^3 mm^3) were performed, with randomized acquisition order. For random undersampling, central k-space (45×35 in ky-kz) was fullysampled, edges randomly discarded, and phase reordering performed as in [5]. Acquisition times were ~4 mins assuming 100% scan-efficiency at 70bpm for both scans. All undersampled data were reconstructed offline using LOST [1]. LOST-reconstructed high-resolution, and standard LGE images were scored by two blinded readers for diagnostic value, presence of LGE(yes/no); and image quality in axial(Ax), coronal(Co) and sagittal (Sa) views (1=poor,4=excellent). Results. Three cases were declared non-diagnostic due to contrast-washout and imperfect inversion-time. LGE was visually present in 14 of the remaining 20 patients based on standard-LGE images, and 12 based on LOST-reconstructed ones (disagreement on one pre- and one postPVI patient). Figure 1 and 2 show comparisons of isotropic vs. non-isotropic LGE images in two patients. Image scores for LOST-LGE: Ax=2.90±0.70,Sa=3.33±0.66,Co=3.00±0.63 Ax=2.90 \pm 0.70, Sa=3.33 \pm 0.66, Co=3.00 \pm 0.63; and standard LGE: Ax=3.76±0.54,Sa=2.48±0.60,Co=2.24±0.44Ax=3.76 \pm 0.54, Sa=2.48 \pm 0.60, Co=2.24 \pm 0.44, where differences were significant in all views. Conclusions. LOST allows isotropic spatial-resolution in LGE for assessment of LA and PV scar. Isotropic resolution allows reformatting LGE images in any orientation and facilitates assessment of scar. Further clinical study is needed to assess if the improved spatial resolution will impact the diagnostic interpretation of data

    Measuring spiritual belief: development and standardization of a beliefs and values scale

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    Background. Higher levels of religious involvement are modestly associated with better health, after taking account of other influences, such as age, sex and social support. However, little account is taken of spiritual beliefs that are not tied to personal or public religious practice. Our objective was to develop a standardized measure of spirituality for use in clinical research. Method. We characterized the core components of spirituality using narrative data from a purposive sample of people, some of whom were near the end of their lives. These data were developed into statements in a scale to measure strength of spiritual beliefs and its reliability, validity and factor structure were evaluated in order to reach a final version. Results. Thirty-nine people took part in the qualitative study to define the nature of spirituality in their lives. These data were used to construct a 47-item instrument that was evaluated in 372 people recruited in medical and non-medical settings. Analysis of these statements led to a 24-item version that was evaluated in a further sample of 284 people recruited in similar settings. The final 20-item questionnaire performed with high test–retest and internal reliability and measures spirituality across a broad religious and non-religious perspective. Conclusions. A measure of spiritual belief that is not limited to religious thought, may contribute to research in psychiatry and medicine

    Exploring the neurocognitive correlates of challenging behaviours in young people with autism spectrum disorder

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    Many young people with autism spectrum disorder display ‘challenging behaviours’, characterised by externalising behaviour and self-injurious behaviours. These behaviours can have a negative impact on a young person’s well-being, family environment and educational achievement. However, the development of effective interventions requires greater knowledge of autism spectrum disorder–specific models of challenging behaviours. Autism spectrum disorder populations are found to demonstrate impairments in different cognitive domains, namely social domains, such as theory of mind and emotion recognition, but also non-social domains such as executive functioning and sensory or perceptual processing. Parent-rated self-injurious behaviour and externalising behaviours, and neurocognitive performance were assessed in a population-derived sample of 100 adolescents with autism spectrum disorder. Structural equation modelling was used to estimate associations between cognitive domains (theory of mind, emotion recognition, executive functioning and perceptual processing) and self-injurious behaviour and externalising behaviours. Poorer theory of mind was associated with increased self-injurious behaviour, whereas poorer perceptual processing was associated with increased externalising behaviours. These associations remained when controlling for language ability. This is the first analysis to examine how a wide range of neurocognitive domains relate to challenging behaviours and suggests specific domains that may be important targets in the development of interventions in adolescents with autism spectrum disorder

    NACCHO Exchange: Health Equity

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    Essential Elements of Health Equity Practice: Partnering to Support Power-Building; Revitalizing Communities: Partnerships to Create Active, Safe Places in Merced County, California; Advancing Health Equity through Regional Collaboration; and Governing for Racial Equity: A Local Health Department's Journe
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