Mechanism of molnupiravir-induced SARS-CoV-2 mutagenesis

Molnupiravir is an orally available antiviral drug candidate currently in phase III trials for the treatment of patients with COVID-19. Molnupiravir increases the frequency of viral RNA mutations and impairs SARS-CoV-2 replication in animal models and in humans. Here, we establish the molecular mechanisms underlying molnupiravir-induced RNA mutagenesis by the viral RNA-dependent RNA polymerase (RdRp). Biochemical assays show that the RdRp uses the active form of molnupiravir, β-d-$N^4$-hydroxycytidine (NHC) triphosphate, as a substrate instead of cytidine triphosphate or uridine triphosphate. When the RdRp uses the resulting RNA as a template, NHC directs incorporation of either G or A, leading to mutated RNA products. Structural analysis of RdRp–RNA complexes that contain mutagenesis products shows that NHC can form stable base pairs with either G or A in the RdRp active center, explaining how the polymerase escapes proofreading and synthesizes mutated RNA. This two-step mutagenesis mechanism probably applies to various viral polymerases and can explain the broad-spectrum antiviral activity of molnupiravir

Perioperative course and quality of life in a prospective randomized multicenter phase III trial, comparing standard lobectomy versus anatomical segmentectomy in patients with non-small cell lung cancer up to 2 cm, stage IA (7th edition of TNM staging system)

OBJECTIVES: For early stage non-small cell lung cancer (NSCLC) retrospective data of functionally compromised patients undergoing segmentectomy showed equal outcomes for perioperative complications and quality of life (QoL) compared with lobectomy patients. However no prospectively randomized data comparing patients eligible for both procedures are available. MATERIALS AND METHODS: We conducted a prospective, randomized, multicenter phase III trial and investigated perioperative complications and QoL in patients with NSCLC stage IA (7th edition) undergoing segmentectomy versus lobectomy. The EORTC Questionnaire Core-30 (QLQ C-30) supplemented by thirteen-item lung cancer-specific module (LC13) was assessed before surgery, at discharge, 6 weeks, 3, 6 and 12 months post-surgery. RESULTS: 108 patients with verified or suspected NSCLC up to 2 cm diameter were enrolled, whereby 54 were assigned to lobectomy and 54 to segmentectomy. Due to nodal disease, tumor size and surgical reasons estimated during the operation, eight patients of the segmentectomy group received a lobectomy. In hospital and 90 days mortality was 0% in both groups. Perioperative complications were observed in 6 (11.3%) patients after segmentectomy and in 8 patients (14.8%) after lobectomy (p = 0.563), while the 90-day morbidity were 17% and 25.9% (9 and 14 patients), respectively (p = 0.452). Twelve months after surgery, there was a significant deterioration to the baselines of physical (p < 0.001) and cognitive functioning (p = 0.025), dyspnea (p < 0.001) and fatigue (p = 0.003) in the lobectomy group. Dyspnea showed a faster recovery in the segmentectomy compared to lobectomy group with statistical significance (p = 0.016 after 12 months). CONCLUSION: In patients with early-stage NSCLC, segmentectomy is associated with a statistically not significant lower perioperative morbidity and appears to provide a superior recovery in QoL compared with lobectomy patients

Results from the German Chronic Kidney Disease (GCKD) study support association of relative telomere length with mortality in a large cohort of patients with moderate chronic kidney disease

Telomere length is known to be inversely associated with aging and has been proposed as a marker for aging-related diseases. Telomere attrition can be accelerated by oxidative stress and inflammation, both commonly present in patients with chronic kidney disease. Here, we investigated whether relative telomere length is associated with mortality in a large cohort of patients with chronic kidney disease stage G3 and A1-3 or G1-2 with overt proteinuria (A3) at enrollment. Relative telomere length was quantified in peripheral blood by a quantitative PCR method in 4,955 patients from the GCKD study, an ongoing prospective observational cohort. Complete four-year follow-up was available from 4,926 patients in whom we recorded 354 deaths. Relative telomere length was a strong and independent predictor of all-cause mortality. Each decrease of 0.1 relative telomere length unit was highly associated with a 14% increased risk of death (hazard ratio1.14 [95% confidence interval 1.06-1.22]) in a model adjusted for age, sex, baseline eGFR, urine albumin/creatinine ratio, diabetes mellitus, prevalent cardiovascular disease, LDL-cholesterol, HDL-cholesterol, smoking, body mass index, systolic and diastolic blood pressure, C-reactive protein and serum albumin. This translated to a 75% higher risk for those in the lowest compared to the highest quartile of relative telomere length. The association was mainly driven by 117 cardiovascular deaths (1.20 [1.05-1.35]) as well as 67 deaths due to infections (1.27 [1.07-1.50]). Thus, our findings support an association of shorter telomere length with all-cause mortality, cardiovascular mortality and death due to infections in patients with moderate chronic kidney disease