Zebrafish (Danio rerio) are widely used as a vertebrate model in cardiovascular research due to their genetic similarity to humans, optical transparency during early development, and amenability to in vivo imaging. This manuscript presents a standardized, accessible protocol for assessing cardiac morphology and function in zebrafish embryos at 96 h post-fertilization (hpf) using brightfield light microscopy. The method includes embryo collection, morphological screening, immobilization in agarose, video recording of the beating heart, and image-based analysis of cardiac parameters such as ventricular dimensions, stroke volume, heart rate, ejection fraction, and cardiac output. Calculations are based on geometric approximations of the ventricle using open-source software (e.g., ImageJ, Zembryo Analyzer). The protocol enables quantitative assessment of cardiac performance using widely available equipment, making it suitable for laboratories with limited resources and high-throughput screenings. In this study, 96 hpf zebrafish larvae were analyzed by recording the beating heart under a light microscope. Key cardiac parameters measured included ventricular dimensions, which were used to calculate stroke volume and heart rate, determined by beats per minute. From these, ejection fraction and cardiac output were derived to assess overall cardiac performance. Representative results from healthy embryos demonstrated consistent ventricular contraction and robust functional indices, while embryos exposed to cadmium showed impaired cardiac morphology and significantly reduced cardiac output. Overall, the method is important for detecting developmental cardiotoxicity and provides a reproducible, non-invasive approach for evaluating cardiac function in vivo during early zebrafish development.

Zebrafish (Danio rerio) are widely used as a vertebrate model in cardiovascular research due to their genetic similarity to humans, optical transparency during early development, and amenability to in vivo imaging. This manuscript presents a standardized, accessible protocol for assessing cardiac morphology and function in zebrafish embryos at 96 h post-fertilization (hpf) using brightfield light microscopy. The method includes embryo collection, morphological screening, immobilization in agarose, video recording of the beating heart, and image-based analysis of cardiac parameters such as ventricular dimensions, stroke volume, heart rate, ejection fraction, and cardiac output. Calculations are based on geometric approximations of the ventricle using open-source software (e.g., ImageJ, Zembryo Analyzer). The protocol enables quantitative assessment of cardiac performance using widely available equipment, making it suitable for laboratories with limited resources and high-throughput screenings. In this study, 96 hpf zebrafish larvae were analyzed by recording the beating heart under a light microscope. Key cardiac parameters measured included ventricular dimensions, which were used to calculate stroke volume and heart rate, determined by beats per minute. From these, ejection fraction and cardiac output were derived to assess overall cardiac performance. Representative results from healthy embryos demonstrated consistent ventricular contraction and robust functional indices, while embryos exposed to cadmium showed impaired cardiac morphology and significantly reduced cardiac output. Overall, the method is important for detecting developmental cardiotoxicity and provides a reproducible, non-invasive approach for evaluating cardiac function in vivo during early zebrafish development.

Introduction: Gentamicin, an aminoglycoside antibiotic, has limited clinical use due to accompanying side effects: nephrotoxicity and ototoxicity. The damage caused by Gentamicin accumulates over time, leading to cell death. Cells of renal proximal tubules are most affected, as are hair cells of the inner ear. One of the presumed mechanisms of toxicity is phospholipidosis, a disorder characterized by the accumulation of phospholipids within cells. Aim: This study aims to investigate, in silico, the mechanism of Gentamicin action in the development of phospholipidosis through interactions with key proteins responsible for lipid transport between the smooth endoplasmic reticulum and late endosomes, as well as enzymes involved in lipid degradation. Material and Methods: We defined target proteins in the KEGG database, and their expression profiles and tissue-specificities were examined using the Human Atlas database. Nine proteins met the final criteria and were further examined by molecular docking using AutoDock Vina. Results: Most of the examined proteins showed high expression in the kidney and corresponding structures of the central nervous system. Docking analysis indicated that the interaction between Gentamicin and ORP1L protein exhibited the lowest Gibbs free energy value of - 8.1 kcal/mol. In comparison, the STARD3 protein had the highest Gibbs free energy value of -5.2 kcal/mol. Amino acid sequences to which Gentamicin binds on the selected proteins were similar within the same protein families. Conclusion: Observed under in silico conditions, Gentamicin interacts with proteins that participate in lysosomal lipid degradation and transport between lysosomes and smooth endoplasmic reticulum.

Introduction: We present a case of Hashimoto's thyroiditis and severe autonomic dysfunction three months after the resolution of the acute phase of COVID-19 infection in a patient with no prior thyroid disease and autonomic dysfunction. Patient Review: We discuss our patient's clinical presentation, diagnostic evaluation, and subsequent management and follow-up. The patient had previously tested positive for COVID-19. A 53-year-old female developed Hashimoto's thyroiditis with normal thyroid function and severe autonomic dysfunction. Her heart rate variability (HRV) is depressed, and her High-Frequency power (HF) is high. Conclusion: Our findings suggest that COVID-19 could have long-term negative effects on antithyroid antibodies. Therefore, testing antithyroid antibodies should be included in the follow-up algorithm for COVID-19 survivors. Autonomic nervous system dysfunction related to COVID-19 may be reversible and early aggressive therapy is necessary. The new technique is important for the early detection of post-acute sequelae of SARS-CoV-2 infection (PASC) in the autonomic nervous system.

Introduction/Aim: Procaine is a local anesthetic from the amino ester group that blocks voltage-gated sodium channels. Since it can cross the placenta in its ionized form, its potential impact on embryonic development is of concern. Zebrafish, which have a significant degree of homology with the human genome, allow for the study of cardiovascular system development with reliable extrapolation to humans. Investigation of the effects of procaine on key proteins involved in zebrafish heart development using molecular docking. Methods: First, a screening of the interaction between procaine and the entire human proteome was performed using FINDSITEcomb software. Based on significant interactions with a high degree of analysis precision, 113 proteins were selected. Using the ZFIN database, the degree of homology between the selected human proteins and zebrafish proteins, tissue specificity, and expression timing were determined. Nine proteins met all the criteria: kcnh6a, kcnh7, kcnh5a, kcnh2a, psen2, rbfa, and zfpl1, and were further investigated through molecular docking in the AutoDock Vina program. Results: Most of the proteins were highly expressed during the blastula stage. Docking results showed that the scn1laa protein and procaine had the lowest Gibbs free energy value (-6 kCal/mol), while the zfp11 protein had the highest value (-4.4 kCal/mol). Procaine binding to the tested proteins revealed similar amino acid sequences within the same protein family. Conclusion: Procaine interacts with proteins involved in zebrafish heart development under in silico conditions. Further analyses on live embryos are needed to complement these findings.