Publications by authors named "Avril A"

Purpose: Despite rigorous evidence of improved quality of life and longer survival, disparities in the utilization of palliative and hospice care persist for racial and ethnic minority patients with cancer. This study evaluated the impact of psychosocial factors on utilization of these services.

Methods: Patients with advanced lung cancer were recruited at a large academic urban hospital.

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Although silicon is a widespread constituent in dental materials, its possible influence on the formation and repair of teeth remains largely unexplored. Here, we studied the effect of two silicic acid-releasing nanomaterials, silica and bioglass, on a living model of pulp consisting of dental pulp stem cells seeded in dense type I collagen hydrogels. Silica nanoparticles and released silicic acid had little effect on cell viability and mineralization efficiency but impacted metabolic activity, delayed matrix remodeling, and led to heterogeneous cell distribution.

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The COVID-19 and mpox crisis has reminded the world of the potentially catastrophic consequences of biological agents. Aside from the natural risk, biological agents can also be weaponized or used for bioterrorism. Dissemination in a population or among livestock could be used to destabilize a nation by creating a climate of terror, by negatively impacting the economy and undermining institutions.

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Article Synopsis
  • Ricin is a highly toxic substance linked to bioterrorism, and while a vaccine (RiVax™) is in development, no effective treatments currently exist for ricin poisoning.
  • * Studies have shown that anti-ricin monoclonal antibodies (mAbs) show great potential for neutralizing ricin and protecting against its effects in animal models.
  • * One specific mAb, RicE5, demonstrated over 90% survival in mice after ricin exposure, even when administered 6 hours or, to a lesser extent, 24 hours post-exposure, suggesting strong therapeutic potential and long-term immunity.
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Introduction: Dominant-negative effects have been described for 10 F11 variants in the literature.

Aim: The current study aimed at identifying putative dominant-negative F11 variants.

Material And Methods: This research consisted in a retrospective analysis of routine laboratory data.

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Ricin toxin is a disulfide-linked glycoprotein (AB toxin) comprising one enzymatic A chain (RTA) and one cell-binding B chain (RTB) contained in the castor bean, a species. Ricin inhibits peptide chain elongation via disruption of the binding between elongation factors and ribosomes, resulting in apoptosis, inflammation, oxidative stress, and DNA damage, in addition to the classically known rRNA damage. Ricin has been used in traditional medicine throughout the world since prehistoric times.

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Identifying mechanisms limiting hybridization is a central goal of speciation research. Here, we studied premating and postmating barriers to hybridization between two ant species, Formica selysi and Formica cinerea. These species hybridize in the Rhône valley in Switzerland, where they form a mosaic hybrid zone, with limited introgression from F.

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The application of demographic history modelling and inference to the study of divergence between species has become a cornerstone of speciation genomics. Speciation histories are usually reconstructed by analysing single populations from each species, assuming that the inferred population history represents the actual speciation history. However, this assumption may not be met when species diverge with gene flow, for example, when secondary contact may be confined to specific geographic regions.

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Anthrax is an acute disease caused by the bacterium , and is a potential biowarfare/bioterrorist agent. Its pulmonary form, caused by inhalation of the spores, is highly lethal and is mainly related to injury caused by the toxins secretion. Antibodies neutralizing the toxins of are regarded as promising therapeutic drugs, and two are already approved by the Federal Drug Administration.

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The coevolution between dispersal and sociality can lead to linked polymorphisms in both traits, which may favour the emergence of supergenes. Supergenes have recently been found to control social organization in several ant lineages. Whether and how these 'social supergenes' also control traits related to dispersal is yet unknown.

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Article Synopsis
  • Ricin is a highly toxic protein and potential biowarfare agent with no approved specific treatment available.
  • Antibodies have been explored for protection, but their effectiveness may vary against different ricin isoforms (D and E) due to high specificity.
  • This study found that certain antibodies have varied neutralizing effects depending on the ricin variant and that a combination of specific antibodies can significantly enhance protective outcomes in mouse models.
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Supergenes underlie striking polymorphisms in nature, yet the evolutionary mechanisms by which they arise and persist remain enigmatic. These clusters of linked loci can spread in populations because they captured coadapted alleles or by selfishly distorting the laws of Mendelian inheritance. Here, we show that the supergene haplotype associated with multiple-queen colonies in Alpine silver ants is a maternal effect killer.

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Supergenes, clusters of tightly linked genes, play a key role in the evolution of complex adaptive variation [1, 2]. Although supergenes have been identified in many species, we lack an understanding of their origin, evolution, and persistence [3]. Here, we uncover 20-40 Ma of evolutionary history of a supergene associated with polymorphic social organization in Formica ants [4].

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Disassortative mating is a powerful mechanism stabilizing polymorphisms at sex chromosomes and other supergenes. The Alpine silver ant, Formica selysi, has two forms of social organization-single-queen and multiple-queen colonies-determined by alternate haplotypes at a large supergene. Here, we explore whether mate preference contributes to the maintenance of the genetic polymorphism at the social supergene.

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Nonrecombining genomic variants underlie spectacular social polymorphisms, from bird mating systems to ant social organization. Because these "social supergenes" affect multiple phenotypic traits linked to survival and reproduction, explaining their persistence remains a substantial challenge. Here, we investigate how large nonrecombining genomic variants relate to colony social organization, mating system and dispersal in the Alpine silver ant, Formica selysi.

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Ant queens often associate to found new colonies, yet the benefits of this behaviour remain unclear. A major hypothesis is that queens founding in groups are protected by social immunity and can better resist disease than solitary queens, due to mutual grooming, sharing of antimicrobials, or higher genetic diversity among their workers. We tested this hypothesis by manipulating the number of queens in incipient colonies of Lasius niger and measuring their resistance to the fungal entomopathogen Metarhizium brunneum.

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Rapidly after the clinical success of the first murine therapeutic antibody licensed in 1985 (muromomab-CD3), the first limits of the therapeutic use of antibodies deriving from hybridoma technology appeared. Indeed, the nonhuman nature of these therapeutic antibodies makes them immunogenic when administrated to patients, which develop anti-drug antibodies (ADA). If repeated drug-administrations are needed, the immune response will accelerate the elimination of the drug, leading to a therapeutic failure, or in the worst case to an anaphylactic reaction against the murine protein.

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The goal of the AntiBotABE Program was the development of recombinant antibodies that neutralize botulinum neurotoxins (BoNT) A, B and E. These serotypes are lethal and responsible for most human botulinum cases. To improve therapeutic efficacy, the heavy and light chains (HC and LC) of the three BoNT serotypes were targeted to achieve a synergistic effect (oligoclonal antibodies).

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Diseases can be caused naturally by biological agents such as bacteria, viruses and toxins (natural risk). However, such biological agents can be intentionally disseminated in the environment by a State (military context) or terrorists to cause diseases in a population or livestock, to destabilize a nation by creating a climate of terror, destabilizing the economy and undermining institutions. Biological agents can be classified according to the severity of illness they cause, its mortality and how easily the agent can be spread.

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Botulinum neurotoxins (BoNTs) cause botulism and are the deadliest naturally-occurring substances known to humans. BoNTs have been classified as one of the category A agents by the Centers for Disease Control and Prevention, indicating their potential use as bioweapons. To counter bio-threat and naturally-occurring botulism cases, well-tolerated antibodies by humans that neutralize BoNTs are relevant.

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Botulinum neurotoxins (BoNTs) are counted among the most toxic substances known and are responsible for human botulism, a life-threatening disease characterized by flaccid muscle paralysis that occurs naturally by food poisoning or colonization of the gastrointestinal tract by BoNT-producing clostridia. To date, 7 serologically distinct serotypes of BoNT (serotype A-G) are known. Due to the high toxicity of BoNTs the Centers for Disease Control and Prevention (CDC) have classified BoNTs as category A agent, including the six biological agents with the highest potential risk of use as bioweapons.

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By working together, social insects achieve tasks that are beyond the reach of single individuals. A striking example of collective behaviour is self-assembly, a process in which individuals link their bodies together to form structures such as chains, ladders, walls or rafts. To get insight into how individual behavioural variation affects the formation of self-assemblages, we investigated the presence of task specialization and the role of past experience in the construction of ant rafts.

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The last decade has seen a surge in research on avian influenza A viruses (IAVs), in part fuelled by the emergence, spread and potential zoonotic importance of highly pathogenic virus subtypes. The mallard (Anas platyrhynchos) is the most numerous and widespread dabbling duck in the world, and one of the most important natural hosts for studying IAV transmission dynamics. In order to predict the likelihood of IAV transmission between individual ducks and to other hosts, as well as between geographical regions, it is important to understand how IAV infection affects the host.

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Wild waterfowl are important reservoir hosts for influenza A virus (IAV) and a potential source of spillover infections in other hosts, including poultry and swine. The emergence of highly pathogenic avian influenza (HPAI) viruses, such as H5N1 and H5N8, and subsequent spread along migratory flyways prompted the initiation of several programs in Europe, North America, and Africa to monitor circulation of HPAI and low-pathogenicity precursor viruses (low-pathogenicity avian influenza [LPAI] viruses). Given the costs of maintaining such programs, it is essential to establish best practice for field methodologies to provide robust data for epidemiological interpretation.

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Background: Botulinum neurotoxins (BoNTs) are considered to be the most toxic substances known on earth and are responsible for human botulism, a life-threatening disease characterized by flaccid muscle paralysis that occurs naturally by food-poisoning or colonization of the gastrointestinal tract by BoNT-producing clostridia. BoNTs have been classified as category A agent by the Centers of Disease Control and Prevention (CDC) and are listed among the six agents with the highest risk to be used as bioweapons. Neutralizing antibodies are required for the development of effective anti-botulism therapies to deal with the potential risk of exposure.

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