scholarly journals Noninvasive temporal detection of early retinal vascular changes during diabetes

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mohammad Ali Saghiri ◽  
Andrew Suscha ◽  
Shoujian Wang ◽  
Ali Mohammad Saghiri ◽  
Christine M. Sorenson ◽  
...  
Keyword(s):  
Disease Progression ◽  
Imaging System ◽  
Therapeutic Interventions ◽  
Retinal Vasculature ◽  
Fundus Images ◽  
Diabetic Mice ◽  
Vascular Changes ◽  
Duration Of Diabetes ◽  
Microvascular Changes ◽  
Canny Edge

Abstract Diabetes associated complications, including diabetic retinopathy and loss of vision, are major health concerns. Detecting early retinal vascular changes during diabetes is not well documented, and only few studies have addressed this domain. The purpose of this study was to noninvasively evaluate temporal changes in retinal vasculature at very early stages of diabetes using fundus images from preclinical models of diabetes. Non-diabetic and Akita/+ male mice with different duration of diabetes were subjected to fundus imaging using a Micron III imaging system. The images were obtained from 4 weeks- (onset of diabetes), 8 weeks-, 16 weeks-, and 24 weeks-old male Akita/+ and non-diabetic mice. In total 104 fundus images were subjected to analysis for various feature extractions. A combination of Canny Edge Detector and Angiogenesis Analyzer plug-ins in ImageJ were utilized to quantify various retinal vascular changes in fundus images. Statistical analyses were conducted to determine significant differences in the various extracted features from fundus images of diabetic and non-diabetic animals. Our novel image analysis method led to extraction of over 20 features. These results indicated that some of these features were significantly changed with a short duration of diabetes, and others remained the same but changed after longer duration of diabetes. These patterns likely distinguish acute (protective) and chronic (damaging) associated changes with diabetes. We show that with a combination of various plugging one can extract over 20 features from retinal vasculature fundus images. These features change during diabetes, thus allowing the quantification of quality of retinal vascular architecture as biomarkers for disease progression. In addition, our method was able to identify unique differences among diabetic mice with different duration of diabetes. The ability to noninvasively detect temporal retinal vascular changes during diabetes could lead to identification of specific markers important in the development and progression of diabetes mediated-microvascular changes, evaluation of therapeutic interventions, and eventual reversal of these changes in order to stop or delay disease progression.

Improving U-Net architecture and graph cuts optimization to classify arterioles and venules in retina fundus images

2021 ◽  
pp. 1-12
Author(s):  
Nguyen Thanh Binh ◽  
Nguyen Mong Hien ◽  
Dang Thanh Tin
Keyword(s):  
Graph Cuts ◽  
The Other ◽  
Retinal Vessels ◽  
Fundus Images ◽  
Vascular Structure ◽  
Vascular Changes ◽  
Lack Of Information ◽  
Retinal Artery ◽  
Diagnostic Indicator ◽  
Better Than

The central retinal artery and its branches supply blood to the inner retina. Vascular manifestations in the retina indirectly reflect the vascular changes and damage in organs such as the heart, kidneys, and brain because of the similar vascular structure of these organs. The diabetic retinopathy and risk of stroke are caused by increased venular caliber. The degrees of these diseases depend on the changes of arterioles and venules. The ratio between the calibers of arterioles and venules (AVR) is various. AVR is considered as the useful diagnostic indicator of different associated health problems. However, the task is not easy because of the lack of information of the features being used to classify the retinal vessels as arterioles and venules. This paper proposed a method to classify the retinal vessels into the arterioles and venules based on improving U-Net architecture and graph cuts. The accuracy of the proposed method is about 97.6%. The results of the proposed method are better than the other methods in RITE dataset and AVRDB dataset.

Near-infrared fundus imaging system with light illumination from an electronic contact lens

2022 ◽  
Vol 15 (2) ◽  
pp. 027001
Author(s):  
Yang Cui ◽  
Taiki Takamatsu ◽  
Koichi Shimizu ◽  
Takeo Miyake
Keyword(s):  
Contact Lens ◽  
Near Infrared ◽  
Imaging System ◽  
Low Cost ◽  
Light Illumination ◽  
Fundus Images ◽  
Fundus Imaging ◽  
Point Spread ◽  
Spread Function ◽  
Dependent Point

Abstract As for the diagnosis and treatment of eye diseases, an ideal fundus imaging system is expected to be portability, low cost, and high resolution. Here, we demonstrate a non-mydriatic near-infrared fundus imaging system with light illumination from an electronic contact lens (E-lens). The E-lens can illuminate the retinal and choroidal structures for capturing the fundus images when voltage is applied wirelessly to the lens. And we also reconstruct the images with a depth-dependent point-spread function to suppress the scattering effect that eventually visualizes the clear fundus images.

scholarly journals Visualization of SARS-CoV-2 infection dynamic

2021 ◽  
Author(s):  
Chengjin Ye ◽  
Kevin Chiem ◽  
Jun-Gyu Park ◽  
Jesus Silvas ◽  
Desarey Morales Vasquez ◽  
...  
Keyword(s):  
Viral Infection ◽  
Cultured Cells ◽  
Imaging System ◽  
Reporter Genes ◽  
Therapeutic Interventions ◽  
Wild Type Virus ◽  
Nucleocapsid Gene ◽  
Recombinant Viruses

Replication-competent recombinant viruses expressing reporter genes provide valuable tools to investigate viral infection. Low levels of reporter gene expressed from previous reporter-expressing rSARS-CoV-2 have jeopardized their use to monitor the dynamics of SARS-CoV-2 infection in vitro or in vivo. Here, we report an alternative strategy where reporter genes were placed upstream of the viral nucleocapsid gene followed by a 2A cleavage peptide. The higher levels of reporter expression using this strategy resulted in efficient visualization of rSARS-CoV-2 in infected cultured cells and K18 hACE2 transgenic mice. Importantly, real-time viral infection was readily tracked using a non-invasive in vivo imaging system and allowed us to rapidly identify antibodies which are able to neutralize SARS-CoV-2 infection in vivo. Notably, these reporter-expressing rSARS-CoV-2 retained wild-type virus like pathogenicity in vivo, supporting their use to investigate viral infection, dissemination, pathogenesis and therapeutic interventions for the treatment of SARS-CoV-2 in vivo.

scholarly journals Hemodynamics in the retinal vasculature during the progression of diabetic retinopathy

2017 ◽  
Vol 1 (4) ◽  
pp. 6-15
Author(s):  
Francesco Calivá ◽  
Georgios Leontidis ◽  
Piotr Chudzik ◽  
Andrew Hunter ◽  
Luca Antiga ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Blood Flow ◽  
Diabetic Retinopathy ◽  
Fluid Dynamic ◽  
First Year ◽  
Retinal Vasculature ◽  
Fundus Images ◽  
Parent Vessel ◽  
Last Stage ◽  
Vascular Trees

Purpose: In this study, it is shown that hemodynamic features are applicable as biomarkers to evaluate the progression of diabetic retinopathy (DR). Methods: Ninety-six fundus images from twenty-four subjects were selected. For each patient, four photographs were captured during the three years before DR and in the first year of DR. The vascular trees, which consisted of a parent vessel and two child branches were extracted, and at the branching nodes, the fluid dynamic conditions were estimated. Results: Veins were mostly affected during the last stage of diabetes before DR. In the arteries, the blood flow in both child branches and the Reynolds number in the smaller child branch were mostly affected. Conclusion: This study showed that hemodynamic features can add further information to the study of the progression of DR.

Morphometric Measurements of The Retinal Vasculature in Fundus Images with Vampire

2015 ◽  
pp. 91-111 ◽  
Author(s):  
Emanuele Trucco ◽  
Andrea Giachetti ◽  
Lucia Ballerini ◽  
Devanjali Relan ◽  
Alessandro Cavinato ◽  
...  
Keyword(s):  
Retinal Vasculature ◽  
Fundus Images ◽  
Morphometric Measurements

scholarly journals A comparison between a white LED confocal imaging system and a conventional flash fundus camera using chromaticity analysis

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Valentina Sarao ◽  
Daniele Veritti ◽  
Enrico Borrelli ◽  
Srini Vas R. Sadda ◽  
Enea Poletti ◽  
...  
Keyword(s):  
Imaging System ◽  
Color Images ◽  
Confocal Imaging ◽  
Fundus Images ◽  
White Led ◽  
Discriminative Power ◽  
High Quality ◽  
Fundus Camera ◽  
Clear Shift ◽  
Color Rendering

Abstract Background Conventional flash fundus cameras capture color images that are oversaturated in the red channel and washed out in the green and blue channels, resulting in a retinal picture that often looks flat and reddish. A white LED confocal device was recently introduced to provide a high-quality retinal image with enhanced color fidelity. In this study, we aimed to evaluate the color rendering properties of the white LED confocal system and compare them to those of a conventional flash fundus camera through chromaticity analysis. Methods A white LED confocal device (Eidon, Centervue, Padova, Italy) and a traditional flash fundus camera (TRC-NW8, Topcon Corporation, Tokyo, Japan) were used to capture fundus images. Color images were evaluated with respect to chromaticity. Analysis was performed according to the image color signature. The color signature of an image was defined as the distribution of its pixels in the rgb chromaticity space. The descriptors used for the analysis are the average and variability of the barycenter positions, the average of the variability and the number of unique colors (NUC) of all signatures. Results Two hundred thirty-three color photographs were acquired with each retinal camera. The images acquired by the confocal white LED device demonstrated an average barycenter position (rgb = [0.448, 0.328, 0.224]) closer to the center of the chromaticity space, while the conventional fundus camera provides images with a clear shift toward red at the expense of the blue and green channels (rgb = [0.574, 0.278, 0.148] (p < 0.001). The variability of the barycenter positions was higher in the white LED confocal system than in the conventional fundus camera. The average variability of the distributions was higher (0.003 ± 0.007, p < 0.001) in the Eidon images compared to the Topcon camera, indicating a greater richness of color. The NUC percentage was higher for the white LED confocal device than for the conventional flash fundus camera (0.071% versus 0.025%, p < 0.001). Conclusions Eidon provides more-balanced color images, with a wider richness of color content, compared to a conventional flash fundus camera. The overall higher chromaticity of Eidon may provide benefits in terms of discriminative power and diagnostic accuracy.

scholarly journals The Epigenetic Link between Polyphenols, Aging and Age-Related Diseases

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1094
Author(s):  
Itika Arora ◽  
Manvi Sharma ◽  
Liou Y. Sun ◽  
Trygve O. Tollefsbol
Keyword(s):  
Disease Progression ◽  
Fruits And Vegetables ◽  
Strong Association ◽  
Therapeutic Interventions ◽  
Dietary Polyphenols ◽  
Age Related ◽  
Non Coding Rna ◽  
Risk Of Mortality ◽  
Complex Process ◽  
Increased Risk

Aging is a complex process mainly categorized by a decline in tissue, cells and organ function and an increased risk of mortality. Recent studies have provided evidence that suggests a strong association between epigenetic mechanisms throughout an organism’s lifespan and age-related disease progression. Epigenetics is considered an evolving field and regulates the genetic code at several levels. Among these are DNA changes, which include modifications to DNA methylation state, histone changes, which include modifications of methylation, acetylation, ubiquitination and phosphorylation of histones, and non-coding RNA changes. As a result, these epigenetic modifications are vital targets for potential therapeutic interventions against age-related deterioration and disease progression. Dietary polyphenols play a key role in modulating these modifications thereby delaying aging and extending longevity. In this review, we summarize recent advancements linking epigenetics, polyphenols and aging as well as critical findings related to the various dietary polyphenols in different fruits and vegetables. In addition, we cover studies that relate polyphenols and their epigenetic effects to various aging-related diseases such as cardiovascular diseases, neurodegenerative diseases, autoimmune disorders, diabetes, osteoporosis and cancer.

Disparate effects on renal and oxidative parameters following RAGE deletion, AGE accumulation inhibition, or dietary AGE control in experimental diabetic nephropathy

2010 ◽  
Vol 298 (3) ◽  
pp. F763-F770 ◽  
Author(s):  
Adeline L. Y. Tan ◽  
Karly C. Sourris ◽  
Brooke E. Harcourt ◽  
Vicki Thallas-Bonke ◽  
Sally Penfold ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Urinary Albumin Excretion ◽  
Uncoupling Protein ◽  
Therapeutic Interventions ◽  
Diabetic Mice ◽  
Wild Type ◽  
Atp Production ◽  
Mitochondrial Superoxide ◽  
Glycation End Products ◽  
Rage Expression

Advanced glycation end products (AGEs) and the receptor for AGEs (RAGE) generate ROS, and therefore this study evaluated the effects of RAGE deletion, decreasing AGE accumulation, or lowering dietary AGE content on oxidative parameters in diabetic nephropathy (DN). Control and diabetic male wild-type and RAGE-deficient (RAGE−/−) mice were fed high- or low-AGE diets, with two groups given the inhibitor of AGE accumulation, alagebrium chloride, and followed for 24 wk. Diabetic RAGE−/−mice were protected against albuminuria, hyperfiltration, glomerulosclerosis, decreased renal mitochondrial ATP production, and excess generation of both mitochondrial and cytosolic superoxide. Whereas glomerulosclerosis, tubulointerstitial expansion, and hyperfiltration were improved in diabetic mice treated with alagebrium, there was no effect on urinary albumin excretion. Both diabetic RAGE−/−and alagebrium-treated mice had an attenuation of renal RAGE expression and decreased renal and urinary AGE (carboxymethyllysine) levels. Low-AGE diets did not confer renoprotection, lower the AGE burden or renal RAGE expression, or improve cytosolic or mitochondrial superoxide generation. Renal uncoupling protein-2 gene expression and mitochondrial membrane potential were attenuated by all therapeutic interventions in diabetic mice. In the present study, diverse approaches to block the AGE-RAGE axis had disparate effects on DN, which has potential clinical implications for the way this axis should be targeted in humans.

scholarly journals Multidose Streptozotocin Induction of Diabetes in BALB/c Mice Induces a Dominant Oxidative Macrophage and a Conversion of TH1 to TH2 Phenotypes During Disease Progression

2005 ◽  
Vol 2005 (4) ◽  
pp. 202-209 ◽  
Author(s):  
Naxin Sun ◽  
Guiwen Yang ◽  
Heng Zhao ◽  
Huub F. J. Savelkoul ◽  
Liguo An
Keyword(s):  
Type 1 Diabetes ◽  
Disease Progression ◽  
Autoimmune Diabetes ◽  
Early Stage ◽  
Redox Status ◽  
No Production ◽  
Diabetic Mice ◽  
Significant Difference ◽  
Diabetes Development

Macrophages (Mp) are implicated in both early and late phases in type 1 diabetes development. Recent study has suggested that a balance between reductive Mp (RMp) and oxidative Mp (OMp) is possible to regulate TH1/TH2 balance. The aim of this study is to investigate the redox status of peritoneal Mp and its cytokine profile during the development of autoimmune diabetes induced by multiple low-dose streptozotocin in BALB/c mice. Meanwhile, the polarization of TH1/TH2 of splenocytes or thymocytes was also examined. We found that peritoneal Mp appeared as an “incomplete” OMp phenotype with decreased icGSH along with disease progression. The OMp showed reduced TNF-α, IL-12, and NO production as well as defective phagocytosis activity compared to nondiabetic controls; however, there was no significant difference with IL-6 production. On the other hand, the levels of IFN-γor IL-4 of splenocytes in diabetic mice were significantly higher compared to the control mice. The ratio of IFN-γto IL-4 was also higher at the early stage of diabetes and then declined several weeks later after the occurrence of diabetes, suggesting a pathogenetic TH1 phenotype from the beginning gradually to a tendency of TH2 during the development of diabetes. Our results implied that likely OMp may be relevant in the development of type 1 diabetes; however, it is not likely the only factor regulating the TH1H/TH2 balance in MLD-STZ-induced diabetic mice.

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