13 research outputs found
CRISPR correction of the PRKAG2 gene mutation in the patient's iPSC-derived cardiomyocytes eliminates the electrophysiological and structural abnormalities
BACKGROUND: Mutations in the PRKAG2 gene encoding the {gamma}-subunit of adenosine monophosphate-kinase (AMPK) cause hypertrophic cardiomyopathy (HCM) and familial-Wolff-Parkinson-White syndrome (WPW). Patients carrying the R302Q mutation in PRKAG2 present sinus bradycardia, escape rhythms, ventricular pre-excitation, supraventricular tachycardia and atrioventricular block. This mutation affects AMPK activity and increases glycogen storage in cardiomyocytes. The link between glycogen storage, WPW, HCM and arrhythmias remains unknown. OBJECTIVE: To investigate the pathological changes caused by the PRKAG2 mutation we tested the hypothesis that the patient's induced Pluripotent Stem Cell-derived cardiomyocytes (iPSC-CMs) display clinical aspects of the disease. METHODS: Using the CRISPR technology we corrected the mutation and generated isogenic iPSC-CMs. Action potentials were recorded from spontaneously firing and paced cardiomyocytes using the patch clamp technique. Using the Micro Electrode Array (MEA) set up we recorded electrograms from iPSC-CMs clusters. Transmission Electron Microscopy (TEM) was used to detect ultrastructural abnormalities in the mutated iPSC-CMs. RESULTS: PRKAG2-mutated iPSC-CMs exhibited abnormal firing patterns, delayed afterdepolarizations (DADs), triggered arrhythmias and augmented Beat Rate Variability (BRV). Importantly, the CRISPR correction eliminated the electrophysiological abnormalities, the augmented glycogen storage and cardiomyocyte hypertrophy. CONCLUSION: PRKAG2-mutated iPSC-CMs displayed functional and structural abnormalities, which were abolished by correcting the mutation in the patient's iPSCs using the CRISPR technology
Scope and limitations of a general unknown screening by gas chromatography—mass spectrometry in acute poisoning
Gold Nanoparticle Based Label-Free SERS Probe for Ultrasensitive and Selective Detection of Trinitrotoluene
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The importance of considering competing risks in recurrence analysis of intracranial meningioma
The risk of recurrence is overestimated by the Kaplan-Meier method when competing events, such as death without recurrence, are present. Such overestimation can be avoided by using the Aalen-Johansen method, which is a direct extension of Kaplan-Meier that accounts for competing events. Meningiomas commonly occur in older individuals and have slow-growing properties, thereby warranting competing risk analysis. The extent to which competing events are considered in meningioma literature is unknown, and the consequences of using incorrect methodologies in meningioma recurrence risk analysis have not been investigated.
We surveyed articles indexed on PubMed since 2020 to assess the usage of competing risk analysis in recent meningioma literature. To compare recurrence risk estimates obtained through Kaplan-Meier and Aalen-Johansen methods, we applied our international database comprising ~ 8,000 patients with a primary meningioma collected from 42 institutions.
Of 513 articles, 169 were eligible for full-text screening. There were 6,537 eligible cases from our PERNS database. The discrepancy between the results obtained by Kaplan-Meier and Aalen-Johansen was negligible among low-grade lesions and younger individuals. The discrepancy increased substantially in the patient groups associated with higher rates of competing events (older patients with high-grade lesions).
The importance of considering competing events in recurrence risk analysis is poorly recognized as only 6% of the studies we surveyed employed Aalen-Johansen analyses. Consequently, most of the previous literature has overestimated the risk of recurrence. The overestimation was negligible for studies involving low-grade lesions in younger individuals; however, overestimation might have been substantial for studies on high-grade lesions