ORCID Profile
0000-0003-2384-740X
Current Organisations
University of Western Australia
,
University of Surrey
,
University College London
,
Lions Eye Institute
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Publisher: Elsevier BV
Date: 09-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2FO02017C
Abstract: T2DM in iduals exhibit macro- and microvascular dysfunction that is pronounced in the legs. Cocoa acutely increases endothelial function of the brachial and the femoral arteries and dilation of microvasculature in the feet of T2DM and healthy in iduals.
Publisher: Springer Science and Business Media LLC
Date: 08-2022
DOI: 10.1186/S40662-022-00299-X
Abstract: To generate and validate a method to estimate axial length estimated (AL est ) from spherical equivalent (SE) and corneal curvature [keratometry (K)], and to determine if this AL est can replace actual axial length (AL act ) for correcting transverse magnification error in optical coherence tomography angiography (OCTA) images using the Littmann-Bennett formula. Data from 1301 participants of the Raine Study Gen2-20 year follow-up were ided into two datasets to generate (n = 650) and validate (n = 651) a relationship between AL, SE, and K. The developed formula was then applied to a separate dataset of 46 participants with AL, SE, and K measurements and OCTA images to estimate and compare the performance of AL est against AL act in correcting transverse magnification error in OCTA images when measuring the foveal avascular zone area (FAZA). The formula for AL est yielded the equation: AL est = 2.102K − 0.4125SE + 7.268, R 2 = 0.794. There was good agreement between AL est and AL act for both study cohorts. The mean difference [standard deviation (SD)] between FAZA corrected with AL est and AL act was 0.002 (0.015) mm 2 with the 95% limits of agreement (LoA) of − 0.027 to 0.031 mm 2 . In comparison, mean difference (SD) between FAZA uncorrected and corrected with AL act was − 0.005 (0.030) mm 2 , with 95% LoA of − 0.064 to 0.054 mm 2 . AL act is more accurate than AL est and hence should be used preferentially in magnification error correction in the clinical setting. FAZA corrected with AL est is comparable to FAZA corrected with AL act , while FAZA measurements using images corrected with AL est have a greater accuracy than measurements on uncorrected images. Hence, in the absence of AL act , clinicians should use AL est to correct for magnification error as this provides for more accurate measurements of fundus parameters than uncorrected images.
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 21-04-2022
DOI: 10.1167/IOVS.63.4.12
Publisher: Wiley
Date: 22-01-2016
DOI: 10.1111/FEBS.13649
Abstract: The anionic proteoglycan serglycin is a major constituent of secretory granules in cytotoxic T lymphocyte (CTL)/natural killer (NK) cells, and is proposed to promote the safe storage of the mostly cationic granule toxins, granzymes and perforin. Despite the extensive defects of mast cell function reported in serglycin gene-disrupted mice, no comprehensive study of physiologically relevant CTL/NK cell populations has been reported. We show that the cytotoxicity of serglycin-deficient CTL and NK cells is severely compromised but can be partly compensated in both cell types when they become activated. Reduced intracellular granzyme B levels were noted, particularly in CD27(+) CD11b(+) mature NK cells, whereas serglycin(-/-) TCR-transgenic (OTI) CD8 T cells also had reduced perforin stores. Culture supernatants from serglycin(-/-) OTI T cells and interleukin-2-activated NK contained increased granzyme B, linking reduced storage with heightened export. By contrast, granzyme A was not significantly reduced in cells lacking serglycin, indicating differentially regulated trafficking and/or storage for the two granzymes. A quantitative analysis of different granule classes by transmission electronmicroscopy showed a selective loss of dense-core granules in serglycin(-/-) CD8(+) CTLs, although other granule types were maintained quantitatively. The findings of the present study show that serglycin plays a critical role in the maturation of dense-core cytotoxic granules in cytotoxic lymphocytes and the trafficking and storage of perforin and granzyme B, whereas granzyme A is unaffected. The skewed retention of cytotoxic effector molecules markedly reduces CTL/NK cell cytotoxicity, although this is partly compensated for as a result of activating the cells by physiological means.
Publisher: Asia Pacific Academy of Ophthalmology
Date: 2017
DOI: 10.22608/APO.201698
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 14-12-2021
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 20-06-2017
Abstract: To evaluate the impact of image magnification correction on superficial retinal vessel density (SRVD) and foveal avascular zone area (FAZA) measurements using optical coherence tomography angiography (OCTA). Participants with healthy retinas were recruited for ocular biometry, refraction, and RTVue XR Avanti OCTA imaging with the 3 × 3-mm protocol. The foveal and parafoveal SRVD and FAZA were quantified with custom software before and after correction for magnification error using the Littman and the modified Bennett formulae. Relative changes between corrected and uncorrected SRVD and FAZA were calculated. Forty subjects were enrolled and the median (range) age of the participants was 30 (18-74) years. The mean (range) spherical equivalent refractive error was -1.65 (-8.00 to +4.88) diopters and mean (range) axial length was 24.42 mm (21.27-28.85). Images from 13 eyes were excluded due to poor image quality leaving 67 for analysis. Relative changes in foveal and parafoveal SRVD and FAZA after correction ranged from -20% to +10%, -3% to +2%, and -20% to +51%, respectively. Image size correction in measurements of foveal SRVD and FAZA was greater than 5% in 51% and 74% of eyes, respectively. In contrast, 100% of eyes had less than 5% correction in measurements of parafoveal SRVD. Ocular biometry should be performed with OCTA to correct image magnification error induced by axial length variation. We advise caution when interpreting interocular and interin idual comparisons of SRVD and FAZA derived from OCTA without image size correction.
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 19-01-2018
DOI: 10.1167/TVST.7.1.6
Publisher: SPIE-Intl Soc Optical Eng
Date: 05-08-2016
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2017
Location: Australia
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: Poland
No related grants have been discovered for Sebastian Litchfield.