Molecular Dynamic Simulations to Determine Individualized Therapy: Tetrabenazine for the GNAO1 Encephalopathy E246K Variant.

INTRODUCTION: GNAO1 encephalopathy is characterized by severe hypotonia, psychomotor retardation, epilepsy, and movement disorders. Genetic variations in GNAO1 have been linked to neurological symptoms including movement disorders like dystonia. The correlation between the E246K mutation in the Gα subunit and aberrant signal transduction of G proteins has been established but no data are reported regarding the efficacy of medical treatment with tetrabenazine. METHODS: Molecular modeling studies were performed to elucidate the molecular mechanisms underlying this mutation. We developed drug efficacy models using molecular dynamic simulations that replicated the behavior of wild-type and mutated proteins in the presence or absence of ligands. RESULTS AND DISCUSSION: We demonstrated that the absence of the mutation leads to normal signal transduction upon receptor activation by the endogenous ligand, but not in the presence of tetrabenazine. In contrast, the presence of the mutation resulted in abnormal signal transduction in the presence of the endogenous ligand, which was corrected by the drug tetrabenazine. Tetrabenazine was identified as a promising therapeutic option for pediatric patients suffering from encephalopathy due to an E246K mutation in the GNAO1 gene validated through molecular dynamics. This is a potential first example of the use of this technique in a rare neurological pediatric disease.

Epidemiological shifts in bronchiolitis patterns and impact of the COVID-19: A two-season comparative study.

BACKGROUND: Bronchiolitis is a common lower respiratory tract infection (LRTI) affecting infants and young children. Respiratory syncytial virus (RSV) has historically been the primary causative agent, but other viruses also contribute to the LRTI epidemiology. Recent changes in epidemiology and clinical patterns due to the coronavirus disease 2019 (COVID-19) pandemic have raised concerns. This study aims to analyze the impact of the pandemic on bronchiolitis epidemiology and severity. METHODS: Two consecutive bronchiolitis seasons (October 2021 to March 2022 and October 2022 to March 2023) were compared. Data on viral agents, hospitalization duration, clinical severity, and respiratory support requirements were collected from pediatric patients at San Marco Hospital, University of Catania. RESULTS: In the 2021-2022 season, RSV was the predominant virus (40%), followed by other viruses, with mild clinical outcomes. In the 2022-2023 season, RSV remained prevalent (58.7%), but other viruses, including rhinovirus (RV) and influenza, showed a significant increase (p < .05) in bronchiolitis cases and severity. Notably, RSV-related bronchiolitis did not exhibit greater severity compared to non-RSV cases in the 2022-2023 season, contrary to the previous year. CONCLUSION: The COVID-19 pandemic appears to have shifted the epidemiological landscape of bronchiolitis, with a peak incidence in November instead of January/February. Non-RSV viruses (RV, influenza A and B, as well as metapneumovirus) have gained prominence, possibly due to viral competition and reduced pandemic-related restrictions. Traditionally, RSV has been the primary pathogen responsible for most bronchiolitis cases. Nonetheless, the findings of this study indicate a shifting landscape in bronchiolitis etiology, with RSV gradually diminishing in its role. Contrary to the previous year, RSV-related bronchiolitis did not exhibit greater severity compared to non-RSV cases in the 2022-2023 season.