44 research outputs found

    Development and international validation of custom-engineered and code-free deep-learning models for detection of plus disease in retinopathy of prematurity: a retrospective study.

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    BACKGROUND: Retinopathy of prematurity (ROP), a leading cause of childhood blindness, is diagnosed through interval screening by paediatric ophthalmologists. However, improved survival of premature neonates coupled with a scarcity of available experts has raised concerns about the sustainability of this approach. We aimed to develop bespoke and code-free deep learning-based classifiers for plus disease, a hallmark of ROP, in an ethnically diverse population in London, UK, and externally validate them in ethnically, geographically, and socioeconomically diverse populations in four countries and three continents. Code-free deep learning is not reliant on the availability of expertly trained data scientists, thus being of particular potential benefit for low resource health-care settings. METHODS: This retrospective cohort study used retinal images from 1370 neonates admitted to a neonatal unit at Homerton University Hospital NHS Foundation Trust, London, UK, between 2008 and 2018. Images were acquired using a Retcam Version 2 device (Natus Medical, Pleasanton, CA, USA) on all babies who were either born at less than 32 weeks gestational age or had a birthweight of less than 1501 g. Each images was graded by two junior ophthalmologists with disagreements adjudicated by a senior paediatric ophthalmologist. Bespoke and code-free deep learning models (CFDL) were developed for the discrimination of healthy, pre-plus disease, and plus disease. Performance was assessed internally on 200 images with the majority vote of three senior paediatric ophthalmologists as the reference standard. External validation was on 338 retinal images from four separate datasets from the USA, Brazil, and Egypt with images derived from Retcam and the 3nethra neo device (Forus Health, Bengaluru, India). FINDINGS: Of the 7414 retinal images in the original dataset, 6141 images were used in the final development dataset. For the discrimination of healthy versus pre-plus or plus disease, the bespoke model had an area under the curve (AUC) of 0·986 (95% CI 0·973-0·996) and the CFDL model had an AUC of 0·989 (0·979-0·997) on the internal test set. Both models generalised well to external validation test sets acquired using the Retcam for discriminating healthy from pre-plus or plus disease (bespoke range was 0·975-1·000 and CFDL range was 0·969-0·995). The CFDL model was inferior to the bespoke model on discriminating pre-plus disease from healthy or plus disease in the USA dataset (CFDL 0·808 [95% CI 0·671-0·909, bespoke 0·942 [0·892-0·982]], p=0·0070). Performance also reduced when tested on the 3nethra neo imaging device (CFDL 0·865 [0·742-0·965] and bespoke 0·891 [0·783-0·977]). INTERPRETATION: Both bespoke and CFDL models conferred similar performance to senior paediatric ophthalmologists for discriminating healthy retinal images from ones with features of pre-plus or plus disease; however, CFDL models might generalise less well when considering minority classes. Care should be taken when testing on data acquired using alternative imaging devices from that used for the development dataset. Our study justifies further validation of plus disease classifiers in ROP screening and supports a potential role for code-free approaches to help prevent blindness in vulnerable neonates. FUNDING: National Institute for Health Research Biomedical Research Centre based at Moorfields Eye Hospital NHS Foundation Trust and the University College London Institute of Ophthalmology. TRANSLATIONS: For the Portuguese and Arabic translations of the abstract see Supplementary Materials section

    The Feasibility of Fingerprick Autologous Blood (FAB) As a Novel Treatment for Severe Dry Eye Disease (DED): Protocol for a Randomised Controlled Trial

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    Introduction: Patients with severe dry eye disease often have limited treatment options with standard non-surgical management focused on the use of artificial tears for lubrication and anti-inflammatory drugs. However, artificial tears do not address the extraordinary complexity of human tears. Crudely, human tears with its vast constituents is essentially filtered blood. Blood and several blood-derived products including autologous serum, have been studied as tears substitutes. This study proposes to test the use of whole, fresh, autologous blood obtained from a fingerprick for treatment of severe dry eye disease. Methods and Analysis: The research team at the two participating sites will approach patients with severe dry eye disease for this study. Recruitment will take place over 12 months and we expect to recruit 60 patients in total. The primary outcome of this feasibility study is to estimate the proportion of eligible patients approached who consent to and comply with study procedures including treatment regimen and completion of required questionnaires. The secondary outcome measures, although not powered for in this feasibility, include corneal inflammation (assessed by Oxford Corneal Staining Guide), patient pain and symptoms scores (assessed by Ocular Surface Disease Index (OSDI) score), and objective signs of dry eye disease as indicated by visual acuity (assessed by Schirmer’s test, tear breakup time, lower and/or upper tear meniscus height measurement). Other secondary outcomes include patients’ quality of life (assessed using the validated EQ-5D-5L questionnaire), cost to the NHS and patient (assessed via use of NHS services and privately purchased over the counter treatment related to dry eyes disease) and safety measure of pressure within the eye (assessed by intra ocular pressure (IOP) score). Ethics and Dissemination: This trial is ongoing and received a favourable research ethics opinion from the East of England - Cambridgeshire and Hertfordshire Research Ethics Committee (REC reference: 17/EE/0508). The results of this study will be published in a suitable peer-review journal and also presented at international ophthalmic conferences. This will also be shared with the study participants as well as with relevant patient groups and charities. Trial Registration Number: NCT0339543

    Population Genetic Diversity and Structure of a Naturally Isolated Plant Species, Rhodiola dumulosa (Crassulaceae)

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    Aims: Rhodiola dumulosa (Crassulaceae) is a perennial diploid species found in high-montane areas. It is distributed in fragmented populations across northern, central and northwestern China. In this study, we aimed to (i) measure the genetic diversity of this species and that of its populations; (ii) describe the genetic structure of these populations across the entire distribution range in China; and (iii) evaluate the extent of gene flow among the naturally fragmented populations. Methods: Samples from 1089 individuals within 35 populations of R. dumulosa were collected, covering as much of the entire distribution range of this species within China as possible. Population genetic diversity and structure were analyzed using AFLP molecular markers. Gene flow among populations was estimated according to the level of population differentiation. Important Findings: The total genetic diversity of R. dumulosa was high but decreased with increasing altitude. Populationstructure analysis indicated that the most closely related populations were geographically restricted and occurred in close proximity to each other. A significant isolation-by-distance pattern, caused by the naturally fragmented population distribution, was observed. At least two distinct gene pools were found in the 35 sampled populations, one composed of populations in northern China and the other composed of populations in central and northwestern China. The calculation of Nei’s gene diversity index revealed that the genetic diversity in the northern China pool (0.1972) was lower than that in th

    Relevance of genetic testing in the gene-targeted trial era: the Rostock Parkinson\u27s disease study

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    \ua9 The Author(s) 2024. Estimates of the spectrum and frequency of pathogenic variants in Parkinson’s disease (PD) in different populations are currently limited and biased. Furthermore, although therapeutic modification of several genetic targets has reached the clinical trial stage, a major obstacle in conducting these trials is that PD patients are largely unaware of their genetic status and, therefore, cannot be recruited. Expanding the number of investigated PD-related genes and including genes related to disorders with overlapping clinical features in large, well-phenotyped PD patient groups is a prerequisite for capturing the full variant spectrum underlying PD and for stratifying and prioritizing patients for gene-targeted clinical trials. The Rostock Parkinson’s disease (ROPAD) study is an observational clinical study aiming to determine the frequency and spectrum of genetic variants contributing to PD in a large international cohort. We investigated variants in 50 genes with either an established relevance for PD or possible phenotypic overlap in a group of 12 580 PD patients from 16 countries [62.3% male; 92.0% White; 27.0% positive family history (FH+), median age at onset (AAO) 59 years] using a next-generation sequencing panel. Altogether, in 1864 (14.8%) ROPAD participants (58.1% male; 91.0% White, 35.5% FH+, median AAO 55 years), a PD-relevant genetic test (PDGT) was positive based on GBA1 risk variants (10.4%) or pathogenic/likely pathogenic variants in LRRK2 (2.9%), PRKN (0.9%), SNCA (0.2%) or PINK1 (0.1%) or a combination of two genetic findings in two genes (∼0.2%). Of note, the adjusted positive PDGT fraction, i.e. the fraction of positive PDGTs per country weighted by the fraction of the population of the world that they represent, was 14.5%. Positive PDGTs were identified in 19.9% of patients with an AAO ≤ 50 years, in 19.5% of patients with FH+ and in 26.9% with an AAO ≤ 50 years and FH+. In comparison to the idiopathic PD group (6846 patients with benign variants), the positive PDGT group had a significantly lower AAO (4 years, P = 9 7 10−34). The probability of a positive PDGT decreased by 3% with every additional AAO year (P = 1 7 10−35). Female patients were 22% more likely to have a positive PDGT (P = 3 7 10−4), and for individuals with FH+ this likelihood was 55% higher (P = 1 7 10−14). About 0.8% of the ROPAD participants had positive genetic testing findings in parkinsonism-, dystonia/dyskinesia- or dementia-related genes. In the emerging era of gene-targeted PD clinical trials, our finding that ∼15% of patients harbour potentially actionable genetic variants offers an important prospect to affected individuals and their families and underlines the need for genetic testing in PD patients. Thus, the insights from the ROPAD study allow for data-driven, differential genetic counselling across the spectrum of different AAOs and family histories and promote a possible policy change in the application of genetic testing as a routine part of patient evaluation and care in PD

    Finger-Prick Autologous Blood (FAB) Eye Drops for Dry Eye Disease: Single Masked Multi-Centre Randomised Controlled Trial

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    PURPOSE: To investigate the quantitative and qualitative efficacy of finger-prick autologous blood (FAB) eye drops versus conventional medical therapy for the treatment of severe dry eye disease (DED). METHODS: Two centre, single masked, randomised controlled trial. Sixty patients in total were recruited with thirty patients (sixty eyes) treated with FAB eye drops four times per day in addition to their conventional DED treatment, and thirty patients (fifty-eight eyes) served as control subjects on conventional treatment alone. Ocular surface disease index (OSDI), Schirmer’s test, fluorescein ocular staining grade (OCSG) Oxford schema and fluorescein tear film break-up time (TBUT), were performed at baseline, at 4 and 8 weeks. RESULTS: OSDI scores significantly decreased in the FAB arm by greater than − 17.68 (− 37.67 to − 2.96, p=0.02) compared to the control arm. There were greater improvements in OCSG and TBUT in the FAB arm but these were non-significant (p> 0.05). CONCLUSION: This feasibility study demonstrates adding FAB eye drops to conventional medical therapy for DED improves mean OSDI symptom score compared to conventional medical therapy alone. It may have particular use in settings where serum is unobtainable. An adequately powered and well-designed randomised trial is needed to further evaluate the long-term clinical benefit of FAB

    Relationship between peripheral-central blood pressure and cardiac-renal damage in kidney transplant recipients

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    PubMedID: 30777552Objectives: Hypertension is a common and important problem in kidney transplant recipients, directly affecting graft and patient survival. Here, we evaluated the relationship between renal-cardiac damage and peripheral and central aortic blood pressure levels in renal transplant recipients. Materials and Methods: We measured peripheral blood pressure (office, daytime ambulatory, and central aortic) in 46 kidney transplant recipients. Biochemical parameters were simultaneously measured. Electro - cardiography and echocardiography were performed. Patients with office blood pressure > 140/90 mm Hg or who were treated with antihypertensive drugs were accepted as hypertensive. Results: Ambulatory blood pressure measurements were higher than office blood pressure measurements (at 135.6/85.6 mm Hg vs 121.8/77.5 mm Hg in hypertensive and at 118.8/77.6 mm Hg vs 101.6/62.5 mm Hg in normotensive patients) (P .05). Left ventricle hyper - trophy was found to be less common in patients using angiotensin-converting enzyme, although not significantly (P >.05). Conclusions: In kidney transplant recipients, blood pressure should be monitored with ambulatory blood pressure measurements, even when normal office pressure levels are shown. The aim of antihypertensive therapy is not only to decrease brachial artery pressure but also to keep central aortic systolic blood pressure in the proper interval, adjusted according to age. This may more effectively prevent the development of renal cardiac damage versus peripheral blood pressure measurement monitoring. © Başkent University 2019 Printed in Turkey. All Rights Reserved
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