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Accumulation of Environmental Radioactivity on the Surface of a High Arctic Ice Cap (Flade Isblink, NE Greenland).
Get PDFUnder climatic warming, glaciers are becoming a secondary source of atmospheric contaminants originally released into the environment decades ago. This phenomenon has been well-documented for glaciers near emission sources. However, less is known about polar ice sheets and ice caps. Radionuclides are one of the contaminants that can be remobilised through ice melting and accumulate in cryoconite material on the surface of glaciers. To understand the cycling of radionuclides in polar glacial contexts, we evaluate the radioactivity of cryoconite samples from Flade Isblink, a High Arctic ice cap in northeast Greenland. The measured radioactivity is among the highest reported across the High Arctic and the highest from Greenland. The high variability observed among the samples is explained by considering the different macroscopic features of single cryoconite deposits. The radioactivity source is compatible with the stratospheric reservoir established during atmospheric nuclear tests and with weapons-grade fissile fuel, likely originating from Novaya Zemlya proving grounds. This study shows that the ability of cryoconite to accumulate radioactivity in remote areas is undisputed, highlighting the need for a deeper understanding of the remobilisation of radioactive species in polar glacial contexts
Willingness to participate in a personalized health cohort - insights from the swiss health study pilot phase.
Get PDFBACKGROUND
This paper explores the feasibility of establishing a large-scale population-based cohort and biobank in Switzerland by assessing potential participants' needs, expectations, and concerns about such an infrastructure providing information on health, lifestyle, and exposure trajectories, the development of disease, and risk factors over time.
METHODS
We utilized a scenario-based questionnaire in the Swiss Health Study pilot phase (2020-2021), involving 1349 adults aged 20-69 from the cantons Vaud and Bern. We conducted descriptive statistics supported by R and qualitative content analysis of n = 374 open responses related to attitudes towards research.
RESULTS
We highlight the benefits and challenges of the scenario-based approach, discuss the sample represented in the pilot phase, and present implications for building a full cohort. We also report on participants' attitudes towards and previous experience with health research. We analyze references regarding informed consent and feedback, attitudes towards the Swiss Health Study, and recommendations on improving its scope, design, and instruments. Results indicate a high interest (90%) in participating in a national health study, with 85% of a random population sample willing to join a long-term cohort. Only 43% were familiar with biobanks, and 44% preferred general consent. Trust was high for Swiss-based public research but lower for researchers from other countries or private sector. Over 95% expressed willingness to complete online questionnaires, undergo physical examination, and donate biosamples. Almost all participants wanted to know the outcomes of the medical tests (99.5%) and the exposure to environmental stressors (95%) from their study center visit. Preferred tools for monitoring sleep, physical activity, and diet were known smartphone apps with automatic data management.
CONCLUSION
Overall, the study reveals a positive attitude towards personalized health research, with a strong willingness to share data and samples. Key insights focus the meaning of informed consent for participation, the relevance of sampling and representativeness, as well as the significance and challenges of personalized feedback, especially regarding environmental health concerns. Findings emphasize participants' supportive yet reflexive stances, underscoring the importance of aligning research values with individual values in personalized health research. These insights contribute valuable considerations for refining the scope, design, and instruments of future cohort studies
Using viral diversity to identify HIV-1 variants under HLA-dependent selection in a systematic viral genome-wide screen.
Get PDFThe pathogenesis of HIV-1 infection is governed by a highly dynamic, time-dependent interaction between the host and the viral genome. In this study, we developed a novel systematic approach to assess the host-virus interaction, using average pairwise viral diversity as a proxy for time since infection, and applied this method to nearly whole viral genome sequences (n = 4,464), human leukocyte antigen (HLA) genotyping data (n = 1,044), and viral RNA load (VL) measurements during the untreated chronic phase (n = 829) of Swiss HIV Cohort Study participants. Our systematic genome-wide screen revealed for 98 HLA/viral-variant pairs a signature of immune-driven selection in the form of an HLA-dependent effect of infection time on the presence of HIV amino acid variants. Of these pairs, 12 were found to have an effect on VL. Furthermore, 28/58 pairs were validated by time-to-event analyses and 48/92 by computational HLA-epitope predictions. Our diversity-based approach allows a powerful and systematic investigation of the interaction between the virus and cellular immunity, revealing a notable subset of such interaction effects. From an evolutionary perspective, these observations underscore the complexity of HLA-mediated selection pressures on the virus that shape viral evolution and pathogenesis
Delayed definitive management of localized prostate cancer: what do we know?
Get PDFDelays in the work-up and definitive management of patients with prostate cancer are common, with logistics of additional work-up after initial prostate biopsy, specialist referrals, and psychological reasons being the most common causes of delays. During the COVID-19 pandemic and the subsequent surges, timing of definitive care delivery with surgery or radiotherapy has become a topic of significant concern for patients with prostate cancer and their providers alike. In response, recommendations for the timing of definitive management of prostate cancer with radiotherapy and radical prostatectomy were published but without a detailed rationale for these recommendations. While the COVID-19 pandemic is behind us, patients are always asking the question: "When should I start radiation or undergo surgery?" In the absence of level I evidence specifically addressing this question, we will hereby present a narrative review to summarize the available data on the effect of treatment delays on oncologic outcomes for patients with localized prostate cancer from prospective and retrospective studies
Apixaban vs Aspirin in Patients With Cancer and Cryptogenic Stroke: A Post Hoc Analysis of the ARCADIA Randomized Clinical Trial.
No full textIMPORTANCE
Approximately 10% to 15% of ischemic strokes are associated with cancer; cancer-associated stroke, particularly when cryptogenic, is associated with high rates of recurrent stroke and major bleeding. Limited data exist on the safety and efficacy of different antithrombotic strategies in patients with cancer and cryptogenic stroke.
OBJECTIVE
To compare apixaban vs aspirin for the prevention of adverse clinical outcomes in patients with history of cancer and cryptogenic stroke.
DESIGN, SETTING, AND PARTICIPANTS
Post hoc analysis of data from 1015 patients with a recent cryptogenic stroke and biomarker evidence of atrial cardiopathy in the Atrial Cardiopathy and Antithrombotic Drugs in Prevention After Cryptogenic Stroke (ARCADIA) trial, a multicenter, randomized, double-blind clinical trial conducted from 2018 to 2023 at 185 stroke centers in North America. Data analysis was performed from October 15, 2023, to May 23, 2024.
EXPOSURES
Oral apixaban, 5 mg (or 2.5 mg if criteria met), twice daily vs oral aspirin, 81 mg, once daily. Subgroups of patients with and without cancer at baseline were examined.
MAIN OUTCOMES AND MEASURES
The primary outcome for this post hoc analysis was a composite of major ischemic or major hemorrhagic events. Major ischemic events were recurrent ischemic stroke, myocardial infarction, systemic embolism, and symptomatic deep vein thrombosis or pulmonary embolism. Major hemorrhagic events included symptomatic intracranial hemorrhage and any major extracranial hemorrhage.
RESULTS
Among 1015 participants (median [IQR] age, 68 [60-76] years; 551 [54.3%] female), 137 (13.5%) had a history of cancer. The median (IQR) follow-up was 1.5 (0.6-2.5) years for patients with history of cancer and 1.5 (0.6-3.0) years for those without history of cancer. Participants with history of cancer, compared with those without history of cancer, had a higher risk of major ischemic or major hemorrhagic events (hazard ratio [HR], 1.73; 95% CI, 1.10-2.71). Among those with history of cancer, 8 of 61 participants (13.1%) randomized to apixaban and 16 of 76 participants (21.1%) randomized to aspirin had a major ischemic or major hemorrhagic event; however, the risk was not significantly different between groups (HR, 0.61; 95% CI, 0.26-1.43). Comparing participants randomized to apixaban vs aspirin among those with cancer, events included recurrent stroke (5 [8.2%] vs 9 [11.8%]), major ischemic events (7 [11.5%] vs 14 [18.4%]), and major hemorrhagic events (1 [1.6%] vs 2 [2.6%]).
CONCLUSIONS AND RELEVANCE
Among participants in the ARCADIA trial with history of cancer, the risk of major ischemic and hemorrhagic events did not differ significantly with apixaban compared with aspirin.
TRIAL REGISTRATION
ClinicalTrials.gov Identifier: NCT03192215
Structural insights into the mechanism and dynamics of proteorhodopsin biogenesis and retinal scavenging.
Get PDFMicrobial ion-pumping rhodopsins (MRs) are extensively studied retinal-binding membrane proteins. However, their biogenesis, including oligomerisation and retinal incorporation, remains poorly understood. The bacterial green-light absorbing proton pump proteorhodopsin (GPR) has emerged as a model protein for MRs and is used here to address these open questions using cryo-electron microscopy (cryo-EM) and molecular dynamics (MD) simulations. Specifically, conflicting studies regarding GPR stoichiometry reported pentamer and hexamer mixtures without providing possible assembly mechanisms. We report the pentameric and hexameric cryo-EM structures of a GPR mutant, uncovering the role of the unprocessed N-terminal signal peptide in the assembly of hexameric GPR. Furthermore, certain proteorhodopsin-expressing bacteria lack retinal biosynthesis pathways, suggesting that they scavenge the cofactor from their environment. We shed light on this hypothesis by solving the cryo-EM structure of retinal-free proteoopsin, which together with mass spectrometry and MD simulations suggests that decanoate serves as a temporary placeholder for retinal in the chromophore binding pocket. Further MD simulations elucidate possible pathways for the exchange of decanoate and retinal, offering a mechanism for retinal scavenging. Collectively, our findings provide insights into the biogenesis of MRs, including their oligomeric assembly, variations in protomer stoichiometry and retinal incorporation through a potential cofactor scavenging mechanism
The critical dynamics of hippocampal seizures.
Get PDFEpilepsy is defined by the abrupt emergence of harmful seizures, but the nature of these regime shifts remains enigmatic. From the perspective of dynamical systems theory, such critical transitions occur upon inconspicuous perturbations in highly interconnected systems and can be modeled as mathematical bifurcations between alternative regimes. The predictability of critical transitions represents a major challenge, but the theory predicts the appearance of subtle dynamical signatures on the verge of instability. Whether such dynamical signatures can be measured before impending seizures remains uncertain. Here, we verified that predictions on bifurcations applied to the onset of hippocampal seizures, providing concordant results from in silico modeling, optogenetics experiments in male mice and intracranial EEG recordings in human patients with epilepsy. Leveraging pharmacological control over neural excitability, we showed that the boundary between physiological excitability and seizures can be inferred from dynamical signatures passively recorded or actively probed in hippocampal circuits. Of importance for the design of future neurotechnologies, active probing surpassed passive recording to decode underlying levels of neural excitability, notably when assessed from a network of propagating neural responses. Our findings provide a promising approach for predicting and preventing seizures, based on a sound understanding of their dynamics
Stromal cell and B cell dialogue potentiates IL-33-enriched lymphoid niches to support eosinophil recruitment and function during type 2 immunity.
Get PDFEosinophils are involved in host protection against multicellular organisms. However, their recruitment to the mesenteric lymph node (mLN) during type 2 immunity is understudied. Our results demonstrate that eosinophil association with lymphoid stromal niches constructed by fibroblastic reticular cells (FRCs) and lymphatic endothelial cells is diminished in mice selectively lacking interleukin (IL)-4Rα or lymphotoxin-β (LTβ) expression on B cells. Furthermore, eosinophil survival, activation, and enhanced Il1rl1 receptor expression are driven by stromal cell and B cell dialogue. The ligation of lymphotoxin-β receptor (LTβR) on FRCs improves eosinophil survival and significantly augments IL-33 expression and eosinophil homing to the mLN, thus confirming the significance of lymphotoxin signaling for granulocyte recruitment. Eosinophil-deficient ΔdblGATA-1 mice show diminished mLN expansion, reduced interfollicular region (IFR) alarmin expression, and delayed helminth clearance, elucidating their importance in type 2 immunity. These findings provide insight into dialogue between stromal cells and B cells, which govern mLN eosinophilia, and the relevance of these mechanisms during type 2 immunity
Clinical evidence for high-risk CE-marked medical devices for glucose management: A systematic review and meta-analysis.
Get PDFAIMS
To conduct a systematic review and meta-analysis, within the Coordinating Research and Evidence for Medical Devices (CORE-MD) project, evaluating CE-marked high-risk devices for glucose management.
MATERIALS AND METHODS
We identified interventional and observational studies evaluating the efficacy and safety of eight automated insulin delivery (AID) systems, two implantable insulin pumps, and three implantable continuous glucose monitoring (CGM) devices. We meta-analysed randomized controlled trials (RCTs) comparing AID systems with other treatments.
RESULTS
A total of 182 studies published between 2009 and 2024 were included, comprising 166 studies on AID systems, six on insulin pumps, and 10 on CGM devices; 26% reported industry funding; 18% were pre-market; 37% had a comparator group. Of the studies identified, 29% were RCTs, 24% were non-randomized trials, and 47% were observational studies. The median (interquartile range) sample size was 48 (28-102), age 34.8 (14-44.2) years, and study duration 17.5 (12-26) weeks. AID systems lowered glycated haemoglobin by 0.5 percentage points (absolute mean difference [MD] = -0.5; 21 RCTs; I2 = 86%) and increased time in target range for sensor glucose level by 13.4 percentage points (MD = 13.4; 14 RCTs; I2 = 90%). At least one safety outcome was assessed in 71% of studies.
CONCLUSIONS
High-risk devices for glucose monitoring or insulin dosing, in particular AID systems, improve glucose control safely, but evidence on diabetes-related end-organ damage is lacking due to short study durations. Methodological heterogeneity highlights the need for developing standards for future pre- and post-market investigations of diabetes-specific high-risk medical devices
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