Survival after Resection of Multiple Tumor Foci of Intrahepatic Cholangiocarcinoma

Background: Multiple tumor foci of intrahepatic cholangiocarcinoma (ICC) are often considered a contra-indication for resection. We sought to define long-term outcomes after resection of ICC in patients with multiple foci. Methods: Patients who underwent resection for ICC between 1990 and 2017 were identified from 12 major HPB centers. Outcomes of patients with solitary lesions, multiple lesions (ML), and oligometastases (OM) were compared. OM were defined as extrahepatic metastases spread to a single organ. Results: One thousand thirteen patients underwent resection of ICC. On final pathology, 185 patients (18.4%) had ML and 27 (2.7%) had OM. Median survival of patients with a solitary tumor was 43.2 months, while the median survival of patients with 2 tumors was 21.2 months; the median survival of patients with 3 or more tumors was 15.3 months (p < 0.001). Five-year survival was 43.3%, 28.0%, and 8.6%, respectively. The median survival of patients without OM was 37.8 months versus 14.9 months among patients with OM (p < 0.001); estimated 5-year survival was 39.3% and 10.6%, respectively. In multivariable analysis, the presence of two lesions was not an independent poor prognostic factor for OS (HR 1.19; 95%CI 0.90-1.57; p = 0.229). However, the presence of three or more tumors was an independent poor prognostic factor for OS (HR 1.97; 95%CI 1.48-2.64; p < 0.001). Conclusion: Resection of multiple liver tumors for patients with ICC did not preclude 5-year survival: in particular, estimated 5-year OS for resection of two tumors was 28.0%.info:eu-repo/semantics/publishedVersio

Pseudohyperphosphorylation has differential effects on polymerization and function of tau isoforms

The microtubule-associated protein tau exists as six isoforms created through the splicing of the second, third, and tenth exons. The isoforms are classified by their number of N-terminal exons (0N, 1N or 2N) and by their number of microtubule-binding repeat regions (3R or 4R). Hyperphosphorylated isoforms accumulate in insoluble aggregates in Alzheimer’s disease and other tauopathies. These neurodegenerative diseases can be categorized based on the isoform content of the aggregates they contain. Hyperphosphorylated tau has the general characteristics of an upward electrophoretic shift, decreased microtubule binding, and an association with aggregation. Previously we have shown that a combination of seven pseudophosphorylation mutations at sites phosphorylated by GSK-3β, referred to as 7-Phos, induced several of these characteristics in full-length 2N4R tau and led to the formation of fewer but longer filaments. We sought to determine whether the same phosphorylation pattern could cause differential effects in the other tau isoforms, possibly through varied conformational effects. Using in vitro techniques, we examined the electrophoretic mobility, aggregation properties and microtubule stabilization of all isoforms and their pseudophosphorylated counterparts. We found that pseudophosphorylation affected each isoform, but in several cases certain isoforms were affected more than others. These results suggest that hyperphosphorylation of tau isoforms could play a major role in determining the isoform composition of tau aggregates in disease

Favourable antibody responses to human coronaviruses in children and adolescents with autoimmune rheumatic diseases

Background: Differences in humoral immunity to coronaviruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), between children and adults remain unexplained and the impact of underlying immune dysfunction or suppression unknown. Here, we sought to examine the antibody immune competence of children and adolescents with prevalent inflammatory rheumatic diseases, juvenile idiopathic arthritis (JIA), juvenile dermatomyositis (JDM) and juvenile systemic lupus erythematosus (JSLE), against the seasonal human coronavirus (HCoV)-OC43 that frequently infects this age group. // Methods: Sera were collected from JIA (n=118), JDM (n=49) and JSLE (n=30) patients, and from healthy control (n=54) children and adolescents, prior to the coronavirus disease-19 (COVID-19) pandemic. We employed sensitive flow cytometry-based assays to determine titres of antibodies that reacted with the spike and nucleoprotein of HCoV-OC43 and cross-reacted with the spike and nucleoprotein of SARS-CoV-2, and compared with respective titres in sera from patients with multisystem inflammatory syndrome in children and adolescents (MIS-C). // Findings: Despite immune dysfunction and immunosuppressive treatment, JIA, JDM and JSLE patients maintained comparable or stronger humoral responses than healthier peers, dominated by IgG antibodies to HCoV-OC43 spike, and harboured IgG antibodies that cross-reacted with SARS-CoV-2 spike. In contrast, responses to HCoV-OC43 and SARS-CoV-2 nucleoproteins exhibited delayed age-dependent class-switching and were not elevated in JIA, JDM and JSLE patients, arguing against increased exposure. // Conclusions: Consequently, autoimmune rheumatic diseases and their treatment were associated with a favourable ratio of spike to nucleoprotein antibodies

Reduced antibody cross-reactivity following infection with B.1.1.7 than with parental SARS-CoV-2 strains

Background: The degree of heterotypic immunity induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains is a major determinant of the spread of emerging variants and the success of vaccination campaigns, but remains incompletely understood. Methods: We examined the immunogenicity of SARS-CoV-2 variant B.1.1.7 (Alpha) that arose in the United Kingdom and spread globally. We determined titres of spike glycoprotein-binding antibodies and authentic virus neutralising antibodies induced by B.1.1.7 infection to infer homotypic and heterotypic immunity. Results: Antibodies elicited by B.1.1.7 infection exhibited significantly reduced recognition and neutralisation of parental strains or of the South Africa variant B.1.351 (Beta) than of the infecting variant. The drop in cross-reactivity was significantly more pronounced following B.1.1.7 than parental strain infection. Conclusions: The results indicate that heterotypic immunity induced by SARS-CoV-2 variants is asymmetric

Inferring stabilizing mutations from protein phylogenies : application to influenza hemagglutinin

One selection pressure shaping sequence evolution is the requirement that a protein fold with sufficient stability to perform its biological functions. We present a conceptual framework that explains how this requirement causes the probability that a particular amino acid mutation is fixed during evolution to depend on its effect on protein stability. We mathematically formalize this framework to develop a Bayesian approach for inferring the stability effects of individual mutations from homologous protein sequences of known phylogeny. This approach is able to predict published experimentally measured mutational stability effects (ΔΔG values) with an accuracy that exceeds both a state-of-the-art physicochemical modeling program and the sequence-based consensus approach. As a further test, we use our phylogenetic inference approach to predict stabilizing mutations to influenza hemagglutinin. We introduce these mutations into a temperature-sensitive influenza virus with a defect in its hemagglutinin gene and experimentally demonstrate that some of the mutations allow the virus to grow at higher temperatures. Our work therefore describes a powerful new approach for predicting stabilizing mutations that can be successfully applied even to large, complex proteins such as hemagglutinin. This approach also makes a mathematical link between phylogenetics and experimentally measurable protein properties, potentially paving the way for more accurate analyses of molecular evolution