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Experimental Eye Research Jun 2024Aging changes the responsiveness of our immune defense, and this decline in immune reactivity plays an important role in the increased susceptibility to infections that...
Aging changes the responsiveness of our immune defense, and this decline in immune reactivity plays an important role in the increased susceptibility to infections that marks progressing age. Aging is also the most pronounced risk factor for development of age-related macular degeneration (AMD), a disease that is characterized by dysfunctional retinal pigment epithelial (RPE) cells and loss of central vision. We have previously shown that acute systemic viral infection has a large impact on the retina in young mice, leading to upregulation of chemokines in the RPE/choroid (RPE/c) and influx of CD8 T cells in the neuroretina. In this study, we sought to investigate the impact of systemic infection on the RPE/c in aged mice to evaluate whether infection in old age could play a role in the pathogenesis of AMD. We found that systemic infection in mice led to upregulation of genes from the crystallin family in the RPE/c from aged mice, but not in the RPE/c from young mice. Crystallin alpha A (CRYAA) was the most upregulated gene, and increased amounts of CRYAA protein were also detected in the aged RPE/c. Increased CRYAA gene and protein expression has previously been found in drusen and choroid from AMD patients, and this protein has also been linked to neovascularization. Since both drusen and neovascularization are important hallmarks of advanced AMD, it is interesting to speculate if upregulation of crystallins in response to infection in old age could be relevant for the pathogenesis of AMD.
PubMed: 38945517
DOI: 10.1016/j.exer.2024.109984 -
American Journal of Ophthalmology Jun 2024To investigate whether neurotrophic keratopathy is present in limbal stem cell deficiency (LSCD) by measuring corneal sensation and characterizing corneal subbasal nerve...
PURPOSE
To investigate whether neurotrophic keratopathy is present in limbal stem cell deficiency (LSCD) by measuring corneal sensation and characterizing corneal subbasal nerve plexus.
DESIGN
Prospective, cross-sectional "case-control" comparative study.
METHODS
Forty-six eyes with LSCD and 14 normal eyes were recruited from 2019 to 2022. Corneal sensation was measured using a Cochet-Bonnet esthesiometer and subbasal nerve plexus was imaged using in vivo confocal microscopy (IVCM) at the central cornea and 4 limbal regions. Subbasal nerve density (SND, number of nerve/mm), subbasal nerve length (SNL, total length of nerve/mm) and subbasal nerve branch density (SNBD, number of branch/mm) were quantified. LSCD was graded to stage 1, 2 and 3 using a previously established staging method` consisting of clinical scores, basal cell density, central corneal epithelial thickness and SNL.
RESULTS
The mean (±SD) cornea sensation in the central cornea and limbus were 29.2 ± 21.5 and 33.6 ± 15.1 mm in the LSCD group and 57.6 ± 5.8 and 54.3 ± 4.7 mm in the control group, respectively (all P < 0.001). In sectoral LSCD, the sensation in the affected regions (29.1 ± 17.6 mm) decreased significantly compared to the unaffected regions (41.4 ± 18.2 mm, P < 0.001). Central corneal SND, SNL and SNBD were reduced by 84.6%, 82.6%, and 89.2%, respectively in LSCD compared to the control (all P < 0.05). The central corneal sensation negatively correlated with the severity of LSCD (rho = -0.64, P < 0.0001) and positively correlated with SND, SNL, and SNBD (rho=0.63, 0.66, and 0.56, respectively; all P < 0.001).
CONCLUSIONS
Corneal sensation was reduced in eyes with LSCD. The degree of corneal sensation reduction positively correlated with the severity of LSCD. This finding demonstrated the co-existence of neurotropic keratopathy in LSCD.
PubMed: 38945348
DOI: 10.1016/j.ajo.2024.06.022 -
NeuroImage Jun 2024Relationships between humans are essential for how we see the world. Using fMRI, we explored the neural basis of homophily, a sociological concept that describes the...
Relationships between humans are essential for how we see the world. Using fMRI, we explored the neural basis of homophily, a sociological concept that describes the tendency to bond with similar others. Our comparison of brain activity between sisters, friends and acquaintances while they watched a movie, indicate that sisters' brain activity is more similar than that of friends and friends' activity is more similar than that of acquaintances. The increased similarity in brain activity measured as inter-subject correlation (ISC) was found both in higher-order brain areas including the default-mode network (DMN) and sensory areas. Increased ISC could not be explained by genetic relation between sisters neither by similarities in eye-movements, emotional experiences, and physiological activity. Our findings shed light on the neural basis of homophily by revealing that similarity in brain activity in the DMN and sensory areas is the stronger the closer is the relationship between the people.
PubMed: 38945181
DOI: 10.1016/j.neuroimage.2024.120712 -
Multiple Sclerosis and Related Disorders Jun 2024Optical coherence tomography (OCT) investigations have revealed that the thickness of inner retinal layers becomes decreased in multiple sclerosis (MS) patients,...
OBJECTIVE
Optical coherence tomography (OCT) investigations have revealed that the thickness of inner retinal layers becomes decreased in multiple sclerosis (MS) patients, compared to healthy control (HC) individuals. To date, a number of studies have applied machine learning to OCT thickness measurements, aiming to enable accurate and automated diagnosis of the disease. However, there have much less emphasis on other less common retinal imaging modalities, like infrared scanning laser ophthalmoscopy (IR-SLO), for classifying MS. IR-SLO uses laser light to capture high-resolution fundus images, often performed in conjunction with OCT to lock B-scans at a fixed position.
METHODS
We incorporated two independent datasets of IR-SLO images from the Isfahan and Johns Hopkins centers, consisting of 164 MS and 150 HC images. A subject-wise data splitting approach was employed to ensure that there was no leakage between training and test datasets. Several state-of-the-art convolutional neural networks (CNNs), including VGG-16, VGG-19, ResNet-50, and InceptionV3, and a CNN with a custom architecture were employed. In the next step, we designed a convolutional autoencoder (CAE) to extract semantic features subsequently given as inputs to four conventional ML classifiers, including support vector machine (SVM), k-nearest neighbor (K-NN), random forest (RF), and multi-layer perceptron (MLP).
RESULTS
The custom CNN (85 % accuracy, 85 % sensitivity, 87 % specificity, 93 % area under the receiver operating characteristics [AUROC], and 94 % area under the precision-recall curve [AUPRC]) outperformed state-of-the-art models (84 % accuracy, 83 % sensitivity, 87 % specificity, 92 % AUROC, and 94 % AUPRC); however, utilizing a combination of the CAE and MLP yields even superior results (88 % accuracy, 86 % sensitivity, 91 % specificity, 94 % AUROC, and 95 % AUPRC).
CONCLUSIONS
We utilized IR-SLO images to differentiate between MS and HC eyes, with promising results achieved using a combination of CAE and MLP. Future multi-center studies involving more heterogenous data are necessary to assess the feasibility of integrating IR-SLO images into routine clinical practice.
PubMed: 38945032
DOI: 10.1016/j.msard.2024.105743 -
Photodiagnosis and Photodynamic Therapy Jun 2024Diabetes, characterized by heightened blood sugar levels, can lead to a condition called Diabetic Retinopathy (DR), which adversely impacts the eyes due to elevated...
Diabetes, characterized by heightened blood sugar levels, can lead to a condition called Diabetic Retinopathy (DR), which adversely impacts the eyes due to elevated blood sugar affecting the retinal blood vessels. The most common cause of blindness in diabetics is thought to be Diabetic Retinopathy (DR), particularly in working-age individuals living in poor nations. People with type 1 or type 2 diabetes may develop this illness, and the risk rises with the length of diabetes and inadequate blood sugar management. There are limits to traditional approaches for the early identification of diabetic retinopathy (DR). In order to diagnose diabetic retinopathy, a model based on Convolutional neural network (CNN) is used in a unique way in this research. The suggested model uses a number of deep learning (DL) models, such as VGG19, Resnet50, and InceptionV3, to extract features. After concatenation, these characteristics are sent through the CNN algorithm for classification. By combining the advantages of several models, ensemble approaches can be effective tools for detecting diabetic retinopathy and increase overall performance and resilience. Classification and image recognition are just a few of the tasks that may be accomplished with ensemble approaches like combination of VGG19,Inception V3 and Resnet 50 to achieve high accuracy. The proposed model is evaluated using a publicly accessible collection of fundus images.VGG19, ResNet50, and InceptionV3 differ in their neural network architectures, feature extraction capabilities, object detection methods, and approaches to retinal delineation. VGG19 may excel in capturing fine details, ResNet50 in recognizing complex patterns, and InceptionV3 in efficiently capturing multi-scale features. Their combined use in an ensemble approach can provide a comprehensive analysis of retinal images, aiding in the delineation of retinal regions and identification of abnormalities associated with diabetic retinopathy. For instance, micro aneurysms, the earliest signs of DR, often require precise detection of subtle vascular abnormalities. VGG19's proficiency in capturing fine details allows for the identification of these minute changes in retinal morphology. On the other hand, ResNet50's strength lies in recognizing intricate patterns, making it effective in detecting neo neo-vascularization and complex hemorrhagic lesions. Meanwhile, InceptionV3's multi-scale feature extraction enables comprehensive analysis, crucial for assessing macular edema and ischemic changes across different retinal layers.
PubMed: 38944405
DOI: 10.1016/j.pdpdt.2024.104259 -
Antiviral Research Jun 2024Herpes simplex virus type 1 (HSV-1) is a neurotropic alphaherpesvirus that establishes a lifelong infection in sensory neurons of infected individuals, accompanied with...
Herpes simplex virus type 1 (HSV-1) is a neurotropic alphaherpesvirus that establishes a lifelong infection in sensory neurons of infected individuals, accompanied with intermittent reactivation of latent virus causing (a)symptomatic virus shedding. Whereas acyclovir (ACV) is a safe and highly effective antiviral to treat HSV-1 infections, long-term usage can lead to emergence of ACV resistant (ACV) HSV-1 and subsequently ACV refractory disease. Here, we isolated an HSV-1 strain from a patient with reactivated herpetic eye disease that did not respond to ACV treatment. The isolate carried a novel non-synonymous F289S mutation in the viral UL23 gene encoding the thymidine kinase (TK) protein. Because ACV needs conversion by viral TK and subsequently cellular kinases to inhibit HSV-1 replication, the UL23 gene is commonly mutated in ACV HSV-1 strains. The potential role of the F289S mutation causing ACV was investigated using CRISPR/Cas9-mediated HSV-1 genome editing. Reverting the F289S mutation in the original clinical isolate to the wild-type sequence S289F resulted in an ACV-sensitive (ACV) phenotype, and introduction of the F289S substitution in an ACV HSV-1 reference strain led to an ACV phenotype. In summary, we identified a new HSV-1 TK mutation in the eye of a patient with ACV refractory herpetic eye disease, which was identified as the causative ACV mutation with the aid of CRISPR/Cas9-mediated genome engineering technology. Direct editing of clinical HSV-1 isolates by CRISPR/Cas9 is a powerful strategy to assess whether single residue substitutions are causative to a clinical ACV phenotype.
PubMed: 38944159
DOI: 10.1016/j.antiviral.2024.105950 -
Journal of Clinical Epidemiology Jun 2024In pursuit of health equity, the World Health Organization has recently called for more extensive monitoring of inequalities in eye health. Population-based eye health...
OBJECTIVE
In pursuit of health equity, the World Health Organization has recently called for more extensive monitoring of inequalities in eye health. Population-based eye health surveys can provide this information, but whether underserved groups are considered in the design, implementation, and reporting of surveys is unknown. We conducted a systematic methodological review of surveys published since 2000 to examine how many population-based eye health surveys have considered underserved groups in their design, reporting, or implementation.
STUDY DESIGN AND SETTING
We identified all population-based cross-sectional surveys reporting the prevalence of objectively measured vision impairment or blindness. Using the PROGRESS+ framework to identify underserved groups, we assessed whether each study considered underserved groups within 15 items across the rationale, sampling or recruitment methods, or the reporting of participation and prevalence rates.
RESULTS
388 eye health surveys were included in this review. Few studies prospectively considered underserved groups during study planning or implementation, for example within their sample size calculations (n=5, ∼1%) or recruitment strategies (n=70, 18%). The most common way that studies considered underserved groups was in the reporting of prevalence estimates (n=374, 96%). We observed a modest increase in the number of distinct PROGRESS+ factors considered by a publication over the study period. Gender/sex was considered within at least one item by 95% (n=267) of studies. Forty-three percent (n=166) of included studies were conducted primarily on underserved population groups, particularly for sub-national studies of people living in rural areas, and we identified examples of robust population-based studies in socially excluded groups.
CONCLUSION
More effort is needed to improve the design, implementation, and reporting of surveys to monitor inequality and promote equity in eye health. Ideally, national-level monitoring of vision impairment and service coverage would be supplemented with smaller-scale studies to understand the disparities experienced by the most underserved groups.
PubMed: 38944059
DOI: 10.1016/j.jclinepi.2024.111444 -
Cell Reports. Medicine Jun 2024Infrared spectroscopy is a powerful technique for probing the molecular profiles of complex biofluids, offering a promising avenue for high-throughput in vitro...
Infrared spectroscopy is a powerful technique for probing the molecular profiles of complex biofluids, offering a promising avenue for high-throughput in vitro diagnostics. While several studies showcased its potential in detecting health conditions, a large-scale analysis of a naturally heterogeneous potential patient population has not been attempted. Using a population-based cohort, here we analyze 5,184 blood plasma samples from 3,169 individuals using Fourier transform infrared (FTIR) spectroscopy. Applying a multi-task classification to distinguish between dyslipidemia, hypertension, prediabetes, type 2 diabetes, and healthy states, we find that the approach can accurately single out healthy individuals and characterize chronic multimorbid states. We further identify the capacity to forecast the development of metabolic syndrome years in advance of onset. Dataset-independent testing confirms the robustness of infrared signatures against variations in sample handling, storage time, and measurement regimes. This study provides the framework that establishes infrared molecular fingerprinting as an efficient modality for populational health diagnostics.
PubMed: 38944038
DOI: 10.1016/j.xcrm.2024.101625 -
Current Biology : CB Jun 2024Rapid eye movement (REM) sleep has been hypothesized to promote emotional resilience, but any neuronal circuits mediating this have not been identified. We find that in...
Rapid eye movement (REM) sleep has been hypothesized to promote emotional resilience, but any neuronal circuits mediating this have not been identified. We find that in mice, somatostatin (Som) neurons in the entopeduncular nucleus (EP)/internal globus pallidus are predominantly active during REM sleep. This unique REM activity is both necessary and sufficient for maintaining normal REM sleep. Inhibiting or exciting EP neurons reduced or increased REM sleep duration, respectively. Activation of the sole downstream target of EP neurons, Vglut2 cells in the lateral habenula (LHb), increased sleep via the ventral tegmental area (VTA). A simple chemogenetic scheme to periodically inhibit the LHb over 4 days selectively removed a significant amount of cumulative REM sleep. Chronic, but not acute, REM reduction correlated with mice becoming anxious and more sensitive to aversive stimuli. Therefore, we suggest that cumulative REM sleep, in part generated by the EP → LHb → VTA circuit identified here, could contribute to stabilizing reactions to habitual aversive stimuli.
PubMed: 38944034
DOI: 10.1016/j.cub.2024.06.010 -
Clinical Neurology and Neurosurgery Jun 2024Parkinson's disease (PD) is the second most prevalent neurodegenerative condition after Alzheimer's disease and it represents one of the fastest emerging neurological... (Review)
Review
Parkinson's disease (PD) is the second most prevalent neurodegenerative condition after Alzheimer's disease and it represents one of the fastest emerging neurological diseases worldwide. PD is usually diagnosed after the third decade of life with symptoms like tremors at rest and muscle stiffness. Rapid Eye Movement sleep behavioral disorder (RBD) is another disorder that is caused by a loss of typical muscle relaxation during sleep with a lot of motor activity. Usually, RBD is strongly associated with PD. Recent studies have demonstrated that PD reduces the life expectancy of patients to 10 and 20 years after being diagnosed. In addition, delayed diagnosis and treatment of these neurological disorders have significant socio-economic impacts on patients, their partners and on the general public. Often, it is not clear about PD associated financial burdens both in low and high-income countries. On the other hand, PD triggers neurological variations that affect differences in the dopamine transporter (DAT) and in glucose metabolism. Therefore, positron emission tomography (PET) using specific DAT radiotracers and fluorine-18 labeled desoxyglucose (FDG) has being considered a key imaging technique that could be applied clinically for the very early diagnosis of RBD and in PD. However, a few myths about PET is that it is very expensive. Here, we looked at the cost of treatment of PD and RBD in relation to early PET imaging. Our finding suggests that PET imaging might also be a cost sparing diagnostic option in the management of patients with PD and RBD, not only for first world countries as it is the case now but also for the third world countries. Therefore, PET is a cost-effective imaging technique for very early diagnostic of RBD and PD.
PubMed: 38944021
DOI: 10.1016/j.clineuro.2024.108404