The Cycad Genotoxin MAM Modulates Brain Cellular Pathways Involved in Neurodegenerative Disease and Cancer in a DNA Damage-Linked Manner

Methylazoxymethanol (MAM), the genotoxic metabolite of the cycad azoxyglucoside cycasin, induces genetic alterations in bacteria, yeast, plants, insects and mammalian cells, but adult nerve cells are thought to be unaffected. We show that the brains of adult C57BL6 wild-type mice treated with a single systemic dose of MAM acetate display DNA damage (O6-methyldeoxyguanosine lesions, O6-mG) that remains constant up to 7 days post-treatment. By contrast, MAM-treated mice lacking a functional gene encoding the DNA repair enzyme O6-mG DNA methyltransferase (MGMT) showed elevated O6-mG DNA damage starting at 48 hours post-treatment. The DNA damage was linked to changes in the expression of genes in cell-signaling pathways associated with cancer, human neurodegenerative disease, and neurodevelopmental disorders. These data are consistent with the established developmental neurotoxic and carcinogenic properties of MAM in rodents. They also support the hypothesis that early-life exposure to MAM-glucoside (cycasin) has an etiological association with a declining, prototypical neurodegenerative disease seen in Guam, Japan, and New Guinea populations that formerly used the neurotoxic cycad plant for food or medicine, or both. These findings suggest environmental genotoxins, specifically MAM, target common pathways involved in neurodegeneration and cancer, the outcome depending on whether the cell can divide (cancer) or not (neurodegeneration). Exposure to MAM-related environmental genotoxins may have relevance to the etiology of related tauopathies, notably, Alzheimer's disease

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

A virtual reality orientation and mobility test for inherited retinal degenerations : testing a proof-of-concept after gene therapy

Purpose: To test the ability of a virtual reality (VR) orientation and mobility (O&M) protocol to serve a measure of functional vision for patients with inherited retinal degenerations (IRDs). Methods: A VR-O&M protocol designed using a commercially available VR hardware was tested in normally sighted control subjects (n=7; ages 10-35yo; Average 22.5yo) and patients with RPE65-associated Leber Congenital Amaurosis (n=3; ages 7-18yo; Average 12.7yo), in two of them before and after gene therapy. Patients underwent perimetry and full-field sensitivity testing. VR-O&M parameters correlated with the visual dysfunction. Results: Visual acuities in RPE65 patients were on average worse than 20/200, dark-adapted sensitivity losses >5 log units, and fields constricted between 20 degrees and 40 degrees. Before treatment, patients required similar to 1000-fold brighter environment to navigate, had at least x4 more collisions, and were slower both to orient and navigate compared to control subjects. Improvements in cone- (by 1-2 L.u.) and rod-mediated (by >4 L.u.) sensitivities post-treatment led to fewer collisions (at least by half) at similar to 100-fold dimmer luminances, and to x4 times faster navigation times. Conclusion: This study provides proof-of-concept data in support for the use of VR-O&M systems to quantify the impact that the visual dysfunction and improvement of vision following treatments has on functional vision in IRDs. The VR-O&M was useful in potentially challenging scenarios such as in pediatric patients with severe IRDs. Translational Relevance: A VR-O&M test will provide much needed flexibility, both in its deployment as well as in the possibility to test various attributes of vision that may be impacted by gene therapy in the setting of translational studies. Precis: This study provides proof-of-concept data in support for the use of a virtual reality orientation and mobility test to quantify the impact of the disease and of treatments thereof on functional vision in inherited retinal degenerations

Development of an Instrument for the Assessment of Health-Related Multi-sectoral Resource Use in Europe: The PECUNIA RUM

Background Measuring objective resource-use quantities is important for generating valid cost estimates in economic evaluations. In the absence of acknowledged guidelines, measurement methods are often chosen based on practicality rather than methodological evidence. Furthermore, few resource-use measurement (RUM) instruments focus on the measurement of resource use in multiple societal sectors and their development process is rarely described. Thorn and colleagues proposed a stepwise approach to the development of RUM instruments, which has been used for developing cost questionnaires for specific trials. However, it remains unclear how this approach can be translated into practice and whether it is applicable to the development of generic self-reported RUM instruments and instruments measuring resource use in multiple sectors. This study provides a detailed description of the practical application of this stepwise approach to the development of a multisectoral RUM instrument developed within the ProgrammE in Costing, resource use measurement and outcome valuation for Use in multi-sectoral National and International health economic evaluAtions (PECUNIA) project. Methods For the development of the PECUNIA RUM, the methodological approach was based on best practice guidelines. The process included six steps, including the definition of the instrument attributes, identification of cost-driving elements in each sector, review of methodological literature and development of a harmonized cross-sectorial approach, development of questionnaire modules and their subsequent harmonization. Results The selected development approach was, overall, applicable to the development of the PECUNIA RUM. However, due to the complexity of the development of a multi-sectoral RUM instrument, additional steps such as establishing a uniform methodological basis, harmonization of questionnaire modules and involvement of a broader range of stakeholders (healthcare professionals, sector-specific experts, health economists) were needed. Conclusion This is the first study that transparently describes the development process of a generic multi-sectoral RUM instrument in health economics and provides insights into the methodological aspects and overall validity of its development process

Proceedings Of The 23Rd Paediatric Rheumatology European Society Congress: Part Two

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