Sarc-Graph: Automated segmentation, tracking, and analysis of sarcomeres in hiPSC-derived cardiomyocytes.

A better fundamental understanding of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) has the potential to advance applications ranging from drug discovery to cardiac repair. Automated quantitative analysis of beating hiPSC-CMs is an important and fast developing component of the hiPSC-CM research pipeline. Here we introduce "Sarc-Graph," a computational framework to segment, track, and analyze sarcomeres in fluorescently tagged hiPSC-CMs. Our framework includes functions to segment z-discs and sarcomeres, track z-discs and sarcomeres in beating cells, and perform automated spatiotemporal analysis and data visualization. In addition to reporting good performance for sarcomere segmentation and tracking with little to no parameter tuning and a short runtime, we introduce two novel analysis approaches. First, we construct spatial graphs where z-discs correspond to nodes and sarcomeres correspond to edges. This makes measuring the network distance between each sarcomere (i.e., the number of connecting sarcomeres separating each sarcomere pair) straightforward. Second, we treat tracked and segmented components as fiducial markers and use them to compute the approximate deformation gradient of the entire tracked population. This represents a new quantitative descriptor of hiPSC-CM function. We showcase and validate our approach with both synthetic and experimental movies of beating hiPSC-CMs. By publishing Sarc-Graph, we aim to make automated quantitative analysis of hiPSC-CM behavior more accessible to the broader research community.

Risk of Parkinson's disease in glaucoma patients: a systematic review and meta-analysis.

OBJECTIVE: To conduct a systematic review and meta-analysis to evaluate the relationship between glaucoma and the risk of Parkinson's disease. METHODS: A systematic search of databases including MEDLINE, EMBASE, and CINAHL were conducted. Grey literature search, including Dissertations and Theses databases and conference abstracts, was performed. Duplicates were removed, and two independent reviewers conducted the screening. We included any primary observational studies that examined the relationship between glaucoma and Parkinson's disease. Study characteristics along with relevant outcome measurements such as hazard ratio (HR), odds ratio (OR), and prevalence were extracted. Meta-analysis using STATA 15.0 was performed, and the presence of heterogeneity was determined using I2 statistics, Z-test, and p-value. RESULTS: A total of 746 citations were found through the databases and grey literature searches. After screening, five studies met the inclusion criteria, and three studies were included in the meta-analysis. There was a non-significant hazard of developing Parkinson's disease (Hazard Ratio = 1.13, 95% CI: [0.99, 1.29]) in patients with glaucoma compared to controls. DISCUSSION: The hazard of developing Parkinson's disease was non-significantly different for those with glaucoma compared to controls; however, there were not enough studies available to draw definitive conclusions.