A comprehensive study of SARS-CoV-2 main protease (Mpro) inhibitor-resistant mutants selected in a VSV-based system.

Nirmatrelvir was the first protease inhibitor specifically developed against the SARS-CoV-2 main protease (3CLpro/Mpro) and licensed for clinical use. As SARS-CoV-2 continues to spread, variants resistant to nirmatrelvir and other currently available treatments are likely to arise. This study aimed to identify and characterize mutations that confer resistance to nirmatrelvir. To safely generate Mpro resistance mutations, we passaged a previously developed, chimeric vesicular stomatitis virus (VSV-Mpro) with increasing, yet suboptimal concentrations of nirmatrelvir. Using Wuhan-1 and Omicron Mpro variants, we selected a large set of mutants. Some mutations are frequently present in GISAID, suggesting their relevance in SARS-CoV-2. The resistance phenotype of a subset of mutations was characterized against clinically available protease inhibitors (nirmatrelvir and ensitrelvir) with cell-based, biochemical and SARS-CoV-2 replicon assays. Moreover, we showed the putative molecular mechanism of resistance based on in silico molecular modelling. These findings have implications on the development of future generation Mpro inhibitors, will help to understand SARS-CoV-2 protease inhibitor resistance mechanisms and show the relevance of specific mutations, thereby informing treatment decisions.

Poor midterm clinical outcomes and a high percentage of unsatisfying results are reported after seizure-related shoulder injuries, especially after posterior proximal humerus fracture-dislocations.

BACKGROUND: Treating seizure-related shoulder injuries is challenging, and an evidence-based consensus to guide clinicians is lacking. The aim of this prospective single-center observational clinical trial was to evaluate the clinical results of a cohort of patients undergoing treatment of seizure-related shoulder injuries, to categorize them according to the lesion's characteristics, with special focus on patients with proximal humerus fracture-dislocations (PHFDs), and to define groups at risk of obtaining unsatisfactory results. We hypothesized that patients with a PHFD, considered the worst-case scenario among these injuries, would report worse clinical results in terms of the quick Disabilities of the Arm, Shoulder, and Hand questionnaire (qDASH) as compared to the other patients. METHODS: Patients referred to a tertiary epilepsy center who have seizure-related shoulder injuries and with a minimum follow-up of 1 year were included. A quality-of-life assessment instrument (EQ-5D-5L), a district-specific patient-reported outcome measure (qDASH), and a pain assessment tool (visual analog scale [VAS]) were used for the clinical outcome evaluation. Subjective satisfaction and fear of new shoulder injuries was also documented. Categorization and subgroup analysis according to the presence and features of selected specific lesions were performed. RESULTS: A total of 111 patients were deemed eligible and 83 were available for follow-up (median age 38 years, 30% females), accounting for a total of 107 injured shoulders. After a median follow-up of 3.9 (1.6-8.2) years, overall moderate clinical results were reported. In addition, 34.1% of the patients reported a VAS score ≥35 mm, indicating moderate to severe pain, and 34.1% a qDASH score ≥40 points, indicating severe disability of an upper limb. These percentages rose to, respectively, 45.5% and 48.5% in the subgroup of patients with PHFDs and to 68.8% and 68.8% in patients experiencing posterior PHFD. Overall, 46.9% of the patients considered themselves unsatisfied with the treatment and 62.5% reported a persistent fear of a new shoulder injury. CONCLUSIONS: Patients with seizure-related shoulder injuries reported only moderate clinical results at their midterm follow-up. Older age, male sex, and absence or discontinuation of antiepileptic drug (AED) treatment were identified as characterizing features of patients with posterior dislocation episodes. In patients with PHFD, a tendency to worse clinical results was observed, with posterior PHFD patients emerging as a definite subgroup at risk of reporting unsatisfying results after treatment.

The nature of Ordovician limestone-marl alternations in the Oslo-Asker District (Norway): witnesses of primary glacio-eustasy or diagenetic rhythms?

Ordovician limestone-marl alternations in the Oslo-Asker District have been interpreted as signaling glacio-eustatic lowstands, which would support a prolonged "Early Palaeozoic Icehouse". However, these rhythmites could alternatively reflect differential diagenesis, without sedimentary trigger. Here, we test both hypotheses through one Darriwilian and three Katian sections. Our methodology consists of a bed-by-bed analysis of palynological (chitinozoan) and geochemical (XRF) data, to evaluate whether the limestone/marl couplets reflect an original cyclic signal. The results reveal similar palynomorph assemblages in limestones and marls. Exceptions, which could be interpreted as reflecting palaeoclimatological fluctuations, exist at the species level: Ancyrochitina bornholmensis seems to be more abundant in the marl samples from the lower Frognerkilen Formation on Nakkholmen Island. However, these rare cases where chitinozoans differ between limestone/marl facies are deemed insufficient for the identification of original cyclicity. The geochemical data show a near-perfect correlation between insoluble elements in the limestone and the marls, which indicates a similar composition of the potential precursor sediment, also in the Frognerkilen Formation. This is consistent with the palynological data. Although an original cyclic pattern could still be recorded by other, uninvestigated parameters, our palaeontological and geochemical data combined do not support the presence of such a signal.