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1.
BMC Ophthalmol ; 17(1): 257, 2018 Jan 04.
Article in English | MEDLINE | ID: mdl-29298687

ABSTRACT

BACKGROUND: Optical Coherence Tomography (OCT) imaging is being increasingly used in clinical practice for the monitoring of papilloedema. The aim is to characterise the extent and location of the Retinal Nerve Fibre Layer (RNFL) Thickness automated segmentation error (SegE) by manual refinement, in a cohort of Idiopathic Intracranial Hypertension (IIH) patients with papilloedema and compare this to controls. METHODS: Baseline Spectral Domain OCT (SDOCT) scans from patients with IIH, and controls with no retinal or optic nerve pathology, were examined. The internal limiting membrane and RNFL thickness of the most severely affected eye was examined for SegE and re-segmented. Using ImageJ, the total area of the RNFL thickness was calculated pre and post re-segmentation and the percentage change was determined. The distribution of RNFL thickness error was qualitatively assessed. RESULTS: Significantly greater SegE (p = 0.009) was present in RNFL thickness total area, assessed using ImageJ, in IIH patients (n = 46, 5% ± 0-58%) compared to controls (n = 14, 1% ± 0-6%). This was particularly evident in moderate to severe optic disc swelling (n = 23, 10% ± 0-58%, p < 0.001). RNFL thickness was unable to be quantified using SDOCT in patients with severe papilloedema. CONCLUSIONS: SegE remain a concern for clinicians using SDOCT to monitor papilloedema in IIH, particularly in the assessment of eyes with moderate to severe oedema. Systematic assessment and manual refinement of SegE is therefore important to ensure the accuracy in longitudinal monitoring of patients.


Subject(s)
Nerve Fibers/pathology , Optic Disk/pathology , Papilledema/diagnosis , Pseudotumor Cerebri/diagnosis , Retinal Ganglion Cells/pathology , Tomography, Optical Coherence/methods , Visual Fields , Adult , Female , Humans , Papilledema/etiology , Papilledema/physiopathology , Pseudotumor Cerebri/complications , Pseudotumor Cerebri/physiopathology , Reproducibility of Results , Severity of Illness Index
3.
Fluids Barriers CNS ; 13(1): 9, 2016 May 31.
Article in English | MEDLINE | ID: mdl-27246837

ABSTRACT

BACKGROUND: In an effort to develop novel treatments for communicating hydrocephalus, we have shown previously that the transforming growth factor-ß antagonist, decorin, inhibits subarachnoid fibrosis mediated ventriculomegaly; however decorin's ability to prevent cerebral cytopathology in communicating hydrocephalus has not been fully examined. Furthermore, the capacity for diffusion tensor imaging to act as a proxy measure of cerebral pathology in multiple sclerosis and spinal cord injury has recently been demonstrated. However, the use of diffusion tensor imaging to investigate cytopathological changes in communicating hydrocephalus is yet to occur. Hence, this study aimed to determine whether decorin treatment influences alterations in diffusion tensor imaging parameters and cytopathology in experimental communicating hydrocephalus. Moreover, the study also explored whether diffusion tensor imaging parameters correlate with cellular pathology in communicating hydrocephalus. METHODS: Accordingly, communicating hydrocephalus was induced by injecting kaolin into the basal cisterns in 3-week old rats followed immediately by 14 days of continuous intraventricular delivery of either human recombinant decorin (n = 5) or vehicle (n = 6). Four rats remained as intact controls and a further four rats served as kaolin only controls. At 14-days post-kaolin, just prior to sacrifice, routine magnetic resonance imaging and magnetic resonance diffusion tensor imaging was conducted and the mean diffusivity, fractional anisotropy, radial and axial diffusivity of seven cerebral regions were assessed by voxel-based analysis in the corpus callosum, periventricular white matter, caudal internal capsule, CA1 hippocampus, and outer and inner parietal cortex. Myelin integrity, gliosis and aquaporin-4 levels were evaluated by post-mortem immunohistochemistry in the CA3 hippocampus and in the caudal brain of the same cerebral structures analysed by diffusion tensor imaging. RESULTS: Decorin significantly decreased myelin damage in the caudal internal capsule and prevented caudal periventricular white matter oedema and astrogliosis. Furthermore, decorin treatment prevented the increase in caudal periventricular white matter mean diffusivity (p = 0.032) as well as caudal corpus callosum axial diffusivity (p = 0.004) and radial diffusivity (p = 0.034). Furthermore, diffusion tensor imaging parameters correlated primarily with periventricular white matter astrocyte and aquaporin-4 levels. CONCLUSIONS: Overall, these findings suggest that decorin has the therapeutic potential to reduce white matter cytopathology in hydrocephalus. Moreover, diffusion tensor imaging is a useful tool to provide surrogate measures of periventricular white matter pathology in communicating hydrocephalus.


Subject(s)
Decorin/pharmacology , Diffusion Tensor Imaging , Hydrocephalus/diagnostic imaging , Hydrocephalus/pathology , Neuroprotective Agents/pharmacology , Recombinant Proteins/pharmacology , Animals , Aquaporin 4/metabolism , Atrophy/diagnostic imaging , Atrophy/drug therapy , Atrophy/metabolism , Atrophy/pathology , Brain/diagnostic imaging , Brain/drug effects , Brain/metabolism , Brain/pathology , Child , Diffusion Magnetic Resonance Imaging , Disease Models, Animal , Glial Fibrillary Acidic Protein/metabolism , Humans , Hydrocephalus/drug therapy , Hydrocephalus/metabolism , Immunohistochemistry , Kaolin , Myelin Sheath/drug effects , Myelin Sheath/metabolism , Myelin Sheath/pathology , Random Allocation , Rats, Sprague-Dawley , Transforming Growth Factor beta/antagonists & inhibitors , Transforming Growth Factor beta/metabolism , White Matter/diagnostic imaging , White Matter/drug effects , White Matter/metabolism , White Matter/pathology
4.
Mater Sci Eng C Mater Biol Appl ; 54: 84-93, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26046271

ABSTRACT

Current processes for coating titanium implants with ceramics involve very high energy techniques with associated high cost and disadvantages such as heterogeneity of the coatings, phase transformations and inability to coat complex structures. In order to address the above problems, we propose a biomimetic hydroxyapatite coating process with the use of peptides that can bind both on titanium surfaces and hydroxyapatite. The peptides enabled homogeneous coating of a titanium surface with hydroxyapatite. The hydroxyapatite-peptide sandwich coating showed no adverse effects on cell number or collagen deposition. This makes the sandwich coated titanium a good candidate for titanium implants used in orthopaedics and dentistry.


Subject(s)
Aptamers, Peptide/chemistry , Coated Materials, Biocompatible/chemistry , Orthopedics/methods , Prostheses and Implants , Biomimetics , Cell Line, Tumor , Ceramics/chemistry , Collagen/chemistry , Durapatite/chemistry , Humans , Microscopy, Electron, Scanning , Microscopy, Fluorescence , Surface Properties , Titanium/chemistry
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