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- Aizawa, Kunihiko, et al.
(author)
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Reservoir Pressure Integral Is Independently Associated With the Reduction in Renal Function in Older Adults
- 2022
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In: Hypertension. - 0194-911X. ; 79:10, s. 2364-2372
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Journal article (peer-reviewed)abstract
- Background: Arterial hemodynamic parameters derived from reservoir-excess pressure analysis exhibit prognostic utility. Reservoir-excess pressure analysis may provide useful information about an influence of altered hemodynamics on target organ such as the kidneys. We determined whether the parameters derived from the reservoir-excess pressure analysis were associated with the reduction in estimated glomerular filtration rate in 542 older adults (69.4±7.9 years, 194 females) at baseline and after 3 years. Methods: Reservoir-excess pressure parameters, including reservoir pressure integral, excess pressure integral, systolic, and diastolic rate constants, were obtained by radial artery tonometry. Results: After 3 years, and in a group of 94 individuals (72.4±7.6 years, 26 females), there was an estimated glomerular filtration rate reduction of >5% per year (median reduction of 20.5% over 3 years). A multivariable logistic regression analysis revealed that higher baseline reservoir pressure integral was independently associated with a smaller reduction in estimated glomerular filtration rate after accounting for conventional cardiovascular risk factors and study centers (odds ratio: 0.660 [95% CIs, 0.494-0.883]; P=0.005). The association remained unchanged after further adjustments for potential confounders and baseline renal function (odds ratio: 0.528 [95% CIs, 0.351-0.794]; P=0.002). No other reservoir-excess pressure parameters exhibited associations with the reduction in renal function. Conclusions: This study demonstrates that baseline reservoir pressure integral was associated with the decline in renal function in older adults at 3-year follow-up, independently of conventional cardiovascular risk factors. This suggests that reservoir pressure integral may play a role in the functional decline of the kidneys.
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- Leeksma, Alexander C., et al.
(author)
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Genomic arrays identify high-risk chronic lymphocytic leukemia with genomic complexity : A multi-center study
- 2020
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In: Haematologica. - 0390-6078. ; 105:5
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Journal article (peer-reviewed)abstract
- Complex karyotype (CK) identified by chromosome-banding analysis (CBA) has shown prognostic value in chronic lymphocytic leukemia (CLL). Genomic arrays offer high-resolution genome-wide detection of copy-number alterations (CNAs) and could therefore be well equipped to detect the presence of a CK. Current knowledge on genomic arrays in CLL is based on outcomes of single center studies, in which different cutoffs for CNA calling were used. To further determine the clinical utility of genomic arrays for CNA assessment in CLL diagnostics, we retrospectively analyzed 2293 arrays from 13 diagnostic laboratories according to established standards. CNAs were found outside regions captured by CLL FISH probes in 34% of patients, and several of them including gains of 8q, deletions of 9p and 18p (p<0.01) were linked to poor outcome after correction for multiple testing. Patients (n=972) could be divided in three distinct prognostic subgroups based on the number of CNAs. Only high genomic complexity (high-GC), defined as 5 CNAs emerged as an independent adverse prognosticator on multivariable analysis for time to first treatment (Hazard ratio: 2.15, 95% CI: 1.36-3.41; p=0.001) and overall survival (Hazard ratio: 2.54, 95% CI: 1.54-4.17; p<0.001; n=528). Lowering the size cutoff to 1 Mb in 647 patients did not significantly improve risk assessment. Genomic arrays detected more chromosomal abnormalities and performed at least as well in terms of risk stratification compared to simultaneous chromosome banding analysis as determined in 122 patients. Our findings highlight genomic array as an accurate tool for CLL risk stratification.
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- Long, Joanna, et al.
(author)
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Frugal filtering optical lenses for point-of-care diagnostics
- 2020
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In: Biomedical Optics Express. - : OPTICAL SOC AMER. - 2156-7085. ; 11:4, s. 1864-1875
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Journal article (peer-reviewed)abstract
- Infectious diseases are the leading cause of morbidity and mortality in low and middle income countries (LMICs). Rapid diagnosis of infections in LMICs presents many challenges, especially in rural areas where access to health care, including diagnostics, is poor. Microscopy is one of the most commonly used platforms to diagnose bacterial infections on clinical samples. Fluorescence microscopy has high sensitivity and specificity but to date is mostly performed within a laboratory setting due to the high-cost, low portability and highly specialist nature of equipment. Point-of-care diagnostics could offer a solution to the challenge of infection diagnosis in LMICs. In this paper we present frugal, easy to manufacture, doped polydimethylsiloxane filtering optical lenses that can be integrated into smartphone microscopes for immediate detection of fluorescently labelled bacteria. This provides a breakthrough technology platform for point-of-care diagnostics. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.
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- Mills, Bethany, et al.
(author)
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Molecular detection of Gram-positive bacteria in the human lung through an optical fiber-based endoscope
- 2021
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In: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Nature. - 1619-7070 .- 1619-7089. ; 48:3, s. 800-807
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Journal article (peer-reviewed)abstract
- Purpose The relentless rise in antimicrobial resistance is a major societal challenge and requires, as part of its solution, a better understanding of bacterial colonization and infection. To facilitate this, we developed a highly efficient no-wash red optical molecular imaging agent that enables the rapid, selective, and specific visualization of Gram-positive bacteria through a bespoke optical fiber-based delivery/imaging endoscopic device. Methods We rationally designed a no-wash, red, Gram-positive-specific molecular imaging agent (Merocy-Van) based on vancomycin and an environmental merocyanine dye. We demonstrated the specificity and utility of the imaging agent in escalating in vitro and ex vivo whole human lung models (n = 3), utilizing a bespoke fiber-based delivery and imaging device, coupled to a wide-field, two-color endomicroscopy system. Results The imaging agent (Merocy-Van) was specific to Gram-positive bacteria and enabled no-wash imaging ofS. aureuswithin the alveolar space of whole ex vivo human lungs within 60 s of delivery into the field-of-view, using the novel imaging/delivery endomicroscopy device. Conclusion This platform enables the rapid and specific detection of Gram-positive bacteria in the human lung.
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- Parker, Helen, et al.
(author)
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Core crosstalk in ordered imaging fibre bundles
- 2020
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In: Optics Letters. - : Optica Publishing Group. - 0146-9592 .- 1539-4794. ; 45:23, s. 6490-6493
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Journal article (peer-reviewed)abstract
- Coherent fiber bundles are used widely for imaging. Commonly, disordered arrays of randomly sized fiber cores avoid proximity between like-cores, which would otherwise result in increased core crosstalk and a negative impact on imaging. Recently, stack-and-draw fiber manufacture techniques have been used to produce fibers with a controlled core layout to minimize core crosstalk. However, one must take manufacturing considerations into account during stack-and-draw fiber design in order to avoid impractical or unachievable fabrication. This comes with a set of practical compromises, such as using only a small number of different core sizes. Through characterization of core crosstalk patterns, this Letter aims to aid the understanding of crosstalk limitations imposed by such compromises in the core layout made for ease of fabrication.
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- Parker, Helen E., et al.
(author)
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A Lab-in-a-Fiber optofluidic device using droplet microfluidics and laser-induced fluorescence for virus detection
- 2022
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In: Scientific Reports. - : Nature Research. - 2045-2322. ; 12:1
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Journal article (peer-reviewed)abstract
- Microfluidics has emerged rapidly over the past 20 years and has been investigated for a variety of applications from life sciences to environmental monitoring. Although continuous-flow microfluidics is ubiquitous, segmented-flow or droplet microfluidics offers several attractive features. Droplets can be independently manipulated and analyzed with very high throughput. Typically, microfluidics is carried out within planar networks of microchannels, namely, microfluidic chips. We propose that fibers offer an interesting alternative format with key advantages for enhanced optical coupling. Herein, we demonstrate the generation of monodisperse droplets within a uniaxial optofluidic Lab-in-a-Fiber scheme. We combine droplet microfluidics with laser-induced fluorescence (LIF) detection achieved through the development of an optical side-coupling fiber, which we term a periscope fiber. This arrangement provides stable and compact alignment. Laser-induced fluorescence offers high sensitivity and low detection limits with a rapid response time making it an attractive detection method for in situ real-time measurements. We use the well-established fluorophore, fluorescein, to characterize the Lab-in-a-Fiber device and determine the generation of ∼ 0.9 nL droplets. We present characterization data of a range of fluorescein concentrations, establishing a limit of detection (LOD) of 10 nM fluorescein. Finally, we show that the device operates within a realistic and relevant fluorescence regime by detecting reverse-transcription loop-mediated isothermal amplification (RT-LAMP) products in the context of COVID-19 diagnostics. The device represents a step towards the development of a point-of-care droplet digital RT-LAMP platform. © 2022, The Author(s).
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- Parker, Helen E., et al.
(author)
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Digital detection and quantification of SARS-CoV-2 in a droplet microfluidic all-fiber device
- 2021
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In: Proceedings MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. - : Chemical and Biological Microsystems Society. ; , s. 1047-1048
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Conference paper (peer-reviewed)abstract
- Silica fibers and capillaries offer opportunities for compact integration of optics with microfluidics while adding advantages such as; flexibility within a high aspect ratio format, uniaxial arrangements, and measurement-at-a-distance. Here, we describe droplet microfluidics-based nucleic acid detection of SARS-CoV-2 in a lab-in-a-fiber platform. The fiber component integrates three modules with key functions: droplet generation, incubation, and fluorescence detection. Within the scope of this work, we developed the component specifically to target the quantification of SARS-CoV-2 viral RNA through reverse-transcription loop-mediated isothermal amplification (RT-LAMP). The all-fiber component could successfully generate uniform droplets and differentiate pre-amplified positive LAMP reaction from negative sample.
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- Parker, Helen E., et al.
(author)
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Viral detection and quantification in a digital droplet microfluidic lab-in-a-fiber device
- 2021
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In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9781510643802
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Conference paper (peer-reviewed)abstract
- In this work, we present the design and fabrication of a fiber device that performs digital droplet microfluidics for molecular diagnostics. A variety of fibers and capillaries were used to build three connected modules dedicated to droplet generation, incubation, and fluorescence detection which enables a uniaxial arrangement. This is in contrast to the traditional 2-dimensional lab-on-a-chip architecture. We characterize our fiber device using a fluorescein dilution series. Our observed detection limit is on the order of 10 nM fluorescein. We demonstrate our all-fiber device for the fluorescence readout after loop-mediated isothermal amplification (LAMP) of synthetic SARS-CoV-2. Our results suggest that this fiber device can successfully distinguish between positive and negative samples in molecular diagnostics. We propose that our fiber device offers benefits over microfluidic chip techniques such as easier optical integration, much simpler sample loading, and faster diagnosis with high specificity and sensitivity. Keywords: All-fiber device, microfluidics, optofluidics, loop-mediated isothermal amplification (LAMP), molecular diagnostics, SARS-CoV2.
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