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Oocytes are among the longest-lived cells in the body and need to preserve their cytoplasm to support proper embryonic development. Protein aggregation is a major threat for intracellular homeostasis in long-lived cells. How oocytes cope with protein aggregation during their extended life is unknown. Here, we find that mouse oocytes accumulate protein aggregates in specialized compartments that we named endolysosomal vesicular assemblies (ELVAs). Combining live-cell imaging, electron microscopy, and proteomics, we found that ELVAs are non-membrane-bound compartments composed of endolysosomes, autophagosomes, and proteasomes held together by a protein matrix formed by RUFY1. Functional assays revealed that in immature oocytes, ELVAs sequester aggregated proteins, including TDP-43, and degrade them upon oocyte maturation. Inhibiting degradative activity in ELVAs leads to the accumulation of protein aggregates in the embryo and is detrimental for embryo survival. Thus, ELVAs represent a strategy to safeguard protein homeostasis in long-lived cells.
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Vesículas Citoplasmáticas , Oócitos , Agregados Proteicos , Animais , Feminino , Camundongos , Autofagossomos , Vesículas Citoplasmáticas/metabolismo , Lisossomos/metabolismo , Oócitos/citologia , Oócitos/metabolismo , Complexo de Endopeptidases do Proteassoma , ProteóliseRESUMO
The Duffy antigen receptor is a seven-transmembrane (7TM) protein expressed primarily at the surface of red blood cells and displays strikingly promiscuous binding to multiple inflammatory and homeostatic chemokines. It serves as the basis of the Duffy blood group system in humans and also acts as the primary attachment site for malarial parasite Plasmodium vivax and pore-forming toxins secreted by Staphylococcus aureus. Here, we comprehensively profile transducer coupling of this receptor, discover potential non-canonical signaling pathways, and determine the cryoelectron microscopy (cryo-EM) structure in complex with the chemokine CCL7. The structure reveals a distinct binding mode of chemokines, as reflected by relatively superficial binding and a partially formed orthosteric binding pocket. We also observe a dramatic shortening of TM5 and 6 on the intracellular side, which precludes the formation of the docking site for canonical signal transducers, thereby providing a possible explanation for the distinct pharmacological and functional phenotype of this receptor.
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Microscopia Crioeletrônica , Sistema do Grupo Sanguíneo Duffy , Receptores de Superfície Celular , Humanos , Receptores de Superfície Celular/metabolismo , Receptores de Superfície Celular/química , Sistema do Grupo Sanguíneo Duffy/metabolismo , Sistema do Grupo Sanguíneo Duffy/química , Transdução de Sinais , Sítios de Ligação , Quimiocinas/metabolismo , Quimiocinas/química , Ligação ProteicaRESUMO
The number of naive T cells decreases and susceptibility to new microbial infections increases with age. Here we describe a previously unknown subset of phenotypically naive human CD8(+) T cells that rapidly secreted multiple cytokines in response to persistent viral antigens but differed transcriptionally from memory and effector T cells. The frequency of these CD8(+) T cells, called 'memory T cells with a naive phenotype' (TMNP cells), increased with age and after severe acute infection and inversely correlated with the residual capacity of the immune system to respond to new infections with age. CD8(+) TMNP cells represent a potential new target for the immunotherapy of persistent infections and should be accounted for and subtracted from the naive pool if truly naive T cells are needed to respond to antigens.
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Envelhecimento/imunologia , Linfócitos T CD8-Positivos/fisiologia , Memória Imunológica , Imunossenescência , Subpopulações de Linfócitos T/fisiologia , Viroses/imunologia , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Humanos , Imunofenotipagem , Ativação Linfocitária , Pessoa de Meia-Idade , Fenótipo , Transcriptoma , Adulto JovemRESUMO
There is a growing appreciation that the direct interaction between bacteriophages and the mammalian host can facilitate diverse and unexplored symbioses. Yet the impact these bacteriophages may have on mammalian cellular and immunological processes is poorly understood. Here, we applied highly purified phage T4, free from bacterial by-products and endotoxins to mammalian cells and analyzed the cellular responses using luciferase reporter and antibody microarray assays. Phage preparations were applied in vitro to either A549 lung epithelial cells, MDCK-I kidney cells, or primary mouse bone marrow derived macrophages with the phage-free supernatant serving as a comparative control. Highly purified T4 phages were rapidly internalized by mammalian cells and accumulated within macropinosomes but did not activate the inflammatory DNA response TLR9 or cGAS-STING pathways. Following 8 hours of incubation with T4 phage, whole cell lysates were analyzed via antibody microarray that detected expression and phosphorylation levels of human signaling proteins. T4 phage application led to the activation of AKT-dependent pathways, resulting in an increase in cell metabolism, survival, and actin reorganization, the last being critical for macropinocytosis and potentially regulating a positive feedback loop to drive further phage internalization. T4 phages additionally down-regulated CDK1 and its downstream effectors, leading to an inhibition of cell cycle progression and an increase in cellular growth through a prolonged G1 phase. These interactions demonstrate that highly purified T4 phages do not activate DNA-mediated inflammatory pathways but do trigger protein phosphorylation cascades that promote cellular growth and survival. We conclude that mammalian cells are internalizing bacteriophages as a resource to promote cellular growth and metabolism.
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Anticorpos , Bacteriófago T4 , Animais , Camundongos , Humanos , Bacteriófago T4/genética , Ciclo Celular , DNA , Mamíferos/genéticaRESUMO
Introgressions of chromosomal segments from related species into wheat are important sources of resistance against fungal diseases. The durability and effectiveness of introgressed resistance genes upon agricultural deployment is highly variable-a phenomenon that remains poorly understood, as the corresponding fungal avirulence genes are largely unknown. Until its breakdown, the Pm17 resistance gene introgressed from rye to wheat provided broad resistance against powdery mildew (Blumeria graminis). Here, we used quantitative trait locus (QTL) mapping to identify the corresponding wheat mildew avirulence effector AvrPm17. It is encoded by two paralogous genes that exhibit signatures of reoccurring gene conversion events and are members of a mildew sublineage specific effector cluster. Extensive haplovariant mining in wheat mildew and related sublineages identified several ancient virulent AvrPm17 variants that were present as standing genetic variation in wheat powdery mildew prior to the Pm17 introgression, thereby paving the way for the rapid breakdown of the Pm17 resistance. QTL mapping in mildew identified a second genetic component likely corresponding to an additional resistance gene present on the 1AL.1RS translocation carrying Pm17. This gene remained previously undetected due to suppressed recombination within the introgressed rye chromosomal segment. We conclude that the initial effectiveness of 1AL.1RS was based on simultaneous introgression of two genetically linked resistance genes. Our results demonstrate the relevance of pathogen-based genetic approaches to disentangling complex resistance loci in wheat. We propose that identification and monitoring of avirulence gene diversity in pathogen populations become an integral part of introgression breeding to ensure effective and durable resistance in wheat.
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Resistência à Doença , Introgressão Genética , Doenças das Plantas , Secale , Triticum , Mapeamento Cromossômico , Resistência à Doença/genética , Melhoramento Vegetal , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Locos de Características Quantitativas , Secale/genética , Secale/microbiologia , Triticum/genética , Triticum/microbiologiaRESUMO
Small RNAs (sRNAs) are involved in gene silencing in multiple ways, including through cross-kingdom transfers from parasites to their hosts. Little is known about the evolutionary mechanisms enabling eukaryotic microbes to evolve functional mimics of host small regulatory RNAs. Here, we describe the identification and functional characterization of SINE_sRNA1, an sRNA family derived from highly abundant short interspersed nuclear element (SINE) retrotransposons in the genome of the wheat powdery mildew pathogen. SINE_sRNA1 is encoded by a sequence motif that is conserved in multiple SINE families and corresponds to a functional plant microRNA (miRNA) mimic targeting Tae_AP1, a wheat gene encoding an aspartic protease only found in monocots. Tae_AP1 has a novel function enhancing both pattern-triggered immunity (PTI) and effector-triggered immunity (ETI), thereby contributing to the cross activation of plant defenses. We conclude that SINE_sRNA1 and Tae_AP1 are functional innovations, suggesting the contribution of transposons to the evolutionary arms race between a parasite and its host. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Ascomicetos , Doenças das Plantas , Imunidade Vegetal , Triticum , Doenças das Plantas/microbiologia , Doenças das Plantas/imunologia , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Triticum/genética , Triticum/microbiologia , Triticum/imunologia , Ascomicetos/patogenicidade , Ascomicetos/genética , Ascomicetos/fisiologia , Imunidade Vegetal/genética , Interações Hospedeiro-Patógeno/genética , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , RNA de Plantas/genética , Elementos de DNA Transponíveis/genética , Elementos Nucleotídeos Curtos e Dispersos/genética , Sequência Conservada/genética , Sequência de BasesRESUMO
Nucleocapsid antibody assays can be used to estimate SARS-CoV-2 infection prevalence in regions implementing spike-based COVID-19 vaccines. However, poor sensitivity of nucleocapsid antibody assays in detecting infection after vaccination has been reported. We derived a lower cutoff for identifying previous infections in a large blood donor cohort (N = 142,599) by using the Ortho VITROS Anti-SARS-CoV-2 Total-N Antibody assay, improving sensitivity while maintaining specificity >98%. We validated sensitivity in samples donated after self-reported swab-confirmed infections diagnoses. Sensitivity for first infections in unvaccinated donors was 98.1% (95% CI 98.0-98.2) and for infection after vaccination was 95.6% (95% CI 95.6-95.7) based on the standard cutoff. Regression analysis showed sensitivity was reduced in the Delta compared with Omicron period, in older donors, in asymptomatic infections, <30 days after infection, and for infection after vaccination. The standard Ortho N antibody threshold demonstrated good sensitivity, which was modestly improved with the revised cutoff.
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Anticorpos Antivirais , Doadores de Sangue , Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Humanos , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/epidemiologia , SARS-CoV-2/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Adulto , Pessoa de Meia-Idade , Masculino , Vacinas contra COVID-19/imunologia , Feminino , Vacinação , Adulto Jovem , Sensibilidade e Especificidade , Adolescente , Idoso , Nucleocapsídeo/imunologia , Teste Sorológico para COVID-19/métodosRESUMO
Oocytes spend the majority of their lifetime in a primordial state. The cellular and molecular biology of primordial oocytes is largely unexplored; yet, it is necessary to study them to understand the mechanisms through which oocytes maintain cellular fitness for decades, and why they eventually fail with age. Here, we develop enabling methods for live-imaging-based comparative characterization of Xenopus, mouse and human primordial oocytes. We show that primordial oocytes in all three vertebrate species contain active mitochondria, Golgi and lysosomes. We further demonstrate that human and Xenopus oocytes have a Balbiani body characterized by a dense accumulation of mitochondria in their cytoplasm. However, despite previous reports, we did not find a Balbiani body in mouse oocytes. Instead, we demonstrate that what was previously used as a marker for the Balbiani body in mouse primordial oocytes is in fact a ring-shaped Golgi that is not functionally associated with oocyte dormancy. This study provides the first insights into the organization of the cytoplasm in mammalian primordial oocytes, and clarifies the relative advantages and limitations of choosing different model organisms for studying oocyte dormancy.
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Oócitos , Organelas , Animais , Citoplasma , Camundongos , Mitocôndrias , Oócitos/metabolismo , Xenopus laevisRESUMO
Combinatorial sensing is especially important in the context of modern drug development to enable fast screening of large data sets. Mesoporous silica materials offer high surface area and a wide range of functionalization possibilities. By adding structural control, the combination of structural and functional control along all length scales opens a new pathway that permits larger amounts of analytes being tested simultaneously for complex sensing tasks. This study presents a fast and simple way to produce mesoporous silica in various shapes and sizes between 0.27-6 mm by using light-induced sol-gel chemistry and digital light processing (DLP). Shape-selective functionalization of mesoporous silica is successfully carried out either after printing using organosilanes or in situ while printing through the use of functional mesopore template for the in situ functionalization approach. Shape-selective adsorption of dyes is shown as a demonstrator toward shape selective screening of potential analytes.
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OBJECTIVES: The main objective was to generate a GLobal OMERACT Ultrasound DActylitis Score (GLOUDAS) in psoriatic arthritis and to test its reliability. To this end, we assessed the validity, feasibility and applicability of ultrasound assessment of finger entheses to incorporate them into the scoring system. METHODS: The study consisted of a stepwise process. First, in cadaveric specimens, we identified enthesis sites of the fingers by ultrasound and gross anatomy, and then verified presence of entheseal tissue in histological samples. We then selected the entheses to be incorporated into a dactylitis scoring system through a Delphi consensus process among international experts. Next, we established and defined the ultrasound components of dactylitis and their scoring systems using Delphi methodology. Finally, we tested the interobserver and intraobserver reliability of the consensus- based scoring systemin patients with psoriatic dactylitis. RESULTS: 32 entheses were identified in cadaveric fingers. The presence of entheseal tissues was confirmed in all cadaveric samples. Of these, following the consensus process, 12 entheses were selected for inclusion in GLOUDAS. Ultrasound components of GLOUDAS agreed on through the Delphi process were synovitis, tenosynovitis, enthesitis, subcutaneous tissue inflammation and periextensor tendon inflammation. The scoring system for each component was also agreed on. Interobserver reliability was fair to good (κ 0.39-0.71) and intraobserver reliability good to excellent (κ 0.80-0.88) for dactylitis components. Interobserver and intraobserver agreement for the total B-mode and Doppler mode scores (sum of the scores of the individual abnormalities) were excellent (interobserver intraclass correlation coefficient (ICC) 0.98 for B-mode and 0.99 for Doppler mode; intraobserver ICC 0.98 for both modes). CONCLUSIONS: We have produced a consensus-driven ultrasound dactylitis scoring system that has shown acceptable interobserver reliability and excellent intraobserver reliability. Through anatomical knowledge, small entheses of the fingers were identified and histologically validated.
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Artrite Psoriásica , Articulações dos Dedos , Índice de Gravidade de Doença , Ultrassonografia , Humanos , Artrite Psoriásica/diagnóstico por imagem , Reprodutibilidade dos Testes , Articulações dos Dedos/diagnóstico por imagem , Articulações dos Dedos/patologia , Ultrassonografia/métodos , Masculino , Feminino , Técnica Delphi , Sinovite/diagnóstico por imagem , Sinovite/patologia , Pessoa de Meia-Idade , Variações Dependentes do Observador , Entesopatia/diagnóstico por imagem , Tenossinovite/diagnóstico por imagem , Cadáver , Estudos de Viabilidade , Adulto , Idoso , Dedos/diagnóstico por imagem , Dedos/patologiaRESUMO
OBJECTIVES: Recently, the HAND osteoarthritis (OA) ULTRASOUND (US) Examination (HOUSE) inflammatory and structural damage scores were developed by the OMERACT US working group. However, the thumb base was not or only partly included. This systematic review examines US scoring methods and scanning techniques assessing thumb base OA, alongside existing evidence on validity, reliability, and responsiveness. METHODS: A comprehensive search strategy in three different databases identified 30 eligible studies. RESULTS: In general, studies predominantly focused on US assessment of the carpometacarpal (CMC) 1 joint, with fewer investigating the scaphotrapeziotrapezoid (STT) joint. Most studies utilized a semiquantitative scale for scoring structural and inflammatory features, aligning with the HOUSE scoring system. Validity was supported by a limited number of studies, with one demonstrating a positive association between US structural damage and radiographic damage, and another showing a similar association with function. Associations between US inflammatory features and pain were observed, albeit with some variability. Reliability was from moderate to good for the CMC1 joint but limited for STT joint. Responsiveness varied across studies. The methodological quality of included studies varied, indicating areas for future research improvement. CONCLUSION: While promising, additional research is necessary to validate the HOUSE scoring system and improve its clinical utility for thumb base OA assessment. Future research should concentrate on optimal scanning positions and on the reliability and responsiveness of the HOUSE scoring system.
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BACKGROUND: Combining pathogen reduction technology (PRT) with blood screening may alleviate concerns over the risk of transfusion-transmitted infections (TTI) and support changes in blood donor selection to potentially increase blood availability. This study aimed to estimate the residual risk of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) transfusion-transmission in Canada after implementing PRT, while eliminating deferrals for sexual risk behaviors. STUDY DESIGN AND METHODS: A probabilistic approach that combined Bayesian networks with Monte Carlo simulations was used to estimate the risk of transfusing HIV-, HBV-, or HCV-contaminated blood components. Different scenarios were considered to compare the current residual risk after PRT implementation, with and without donor deferral criteria for sexual risk behaviors. Donor profiles and blood component outcomes were simulated based on a literature review including the prevalence and incidence of HIV, HBV, and HCV in the Canadian blood donor population; the use of current blood screening assays; and HIV, HBV, and HCV blood donor viral loads. RESULTS: In the universal PRT scenario (i.e., with PRT/without deferral criteria), the estimated risks of HIV, HBV, and HCV transmission were significantly lower than those in the currently observed scenario (i.e., without PRT/with deferral criteria). CONCLUSIONS: This risk model suggests that PRT for platelets and plasma (and eventually for RBCs when available) significantly reduces the residual risks of HIV, HBV and HCV transfusion-transmission and could enable the removal of blood donor deferral criteria for sexual risk behaviors.
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BACKGROUND: HIV, HBV, and HCV infections for ~60% of the US blood supply are monitored by TTIMS with syphilis added in 2020. STUDY DESIGN AND METHODS: Data were compiled from October 2020 to September 2022. Syphilis prevalence was estimated for allogeneic and directed donors who were consensus positive (CP) and the subset of those with confirmed-active infections (AI). Prevalence and incidence were stratified by demographics for two consecutive 1-year periods, starting October 1, 2020 and for both years combined. Incidence was estimated for repeat donors. Associations between syphilis positivity and other infections were evaluated. RESULTS: Among 14.75 million donations, syphilis prevalence was 28.4/100,000 donations and significantly higher during the second year compared to the first year. Overall, syphilis incidence for the two-year period was 10.8/100,000 person-years. The adjusted odds of a CP infection were 1.18 (95% CI: 1.11, 1.26) times higher in the second year compared to the first, and for AI, 1.22 (95% CI: 1.10, 1.35) times higher in year 2. Highest rates occurred among males, first-time, Black, and younger (ages 18-39) donors, and those in the South US Census region. Syphilis CP donors were 64 (95% CI: 46, 89) times more likely to be HIV CP, and AI donors 77 (95% CI: 52, 114) times more likely to be HIV CP than non-CP donors, when controlling for confounders. SUMMARY/CONCLUSIONS: Syphilis prevalence increased over the study period mirroring national trends reported by CDC and is significantly associated with HIV CP.
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Infecções por HIV , Sífilis , Masculino , Humanos , Sífilis/epidemiologia , Estudos Soroepidemiológicos , Incidência , Doadores de Sangue , Infecções por HIV/epidemiologia , PrevalênciaRESUMO
BACKGROUND: Long COVID is a common condition lacking consensus definition; determinants remain incompletely understood. Characterizing immune profiles associated with long COVID could support the development of preventive and therapeutic strategies. METHODS: We used a survey to investigate blood donors' infection/vaccination history and acute/persistent symptoms following COVID-19. The prevalence of long COVID was evaluated using self-report and an adapted definition from the RECOVER study. We evaluated factors associated with long COVID, focusing on anti-spike and anti-nucleocapsid SARS-CoV-2 antibodies. Lastly, we investigated long COVID clinical subphenotypes using hierarchical clustering. RESULTS: Of 33,610 participants, 16,003 (48%) reported having had COVID-19; 1853 (12%) had self-reported long COVID, 685 (4%) met an adapted RECOVER definition, and 2050 (13%) met at least one definition. Higher anti-nucleocapsid levels measured 12-24 weeks post-infection were associated with higher risk of self-reported and RECOVER long COVID. Higher anti-spike IgG levels measured 12-24 weeks post-infection were associated with lower risk of self-reported long COVID. Higher total anti-spike measured 24-48 weeks post-infection was associated with lower risk of RECOVER long COVID. Cluster analysis identified four clinical subphenotypes; patterns included neurological and psychiatric for cluster 1; neurological and respiratory for cluster 2; multi-systemic for cluster 3; and neurological for cluster 4. DISCUSSION: Long COVID prevalence in blood donors varies depending on the adopted definition. Anti-SARS-CoV-2 antibodies were time-dependently associated with long COVID; higher anti-nucleocapsid levels were associated with higher risk; and higher anti-spike levels were associated with lower risk of long COVID. Different underlying pathophysiologic mechanisms may be associated with distinct clinical subphenotypes.
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BACKGROUND AND OBJECTIVES: Until recently, gay, bisexual and other men who have sex with men (MSM) were deferred from donating blood for 3-12 months since the last male-to-male sexual contact. This MSM deferral has been discontinued by several high-income countries (HIC) that now perform gender-neutral donor selection. MATERIALS AND METHODS: An international symposium (held on 20-04-2023) gathered experts from seven HICs to (1) discuss how this paradigm shift might affect the mitigation strategies for transfusion-transmitted infections and (2) address the challenges related to gender-neutral donor selection. RESULTS: Most countries employed a similar approach for implementing a gender-neutral donor selection policy: key stakeholders were consulted; the transition was bridged by time-limited deferrals; donor compliance was monitored; and questions or remarks on anal sex and the number and/or type of sexual partners were often added. Many countries have now adopted a gender-neutral approach in which questions on pre- and post-exposure prophylaxis for human immunodeficiency virus (HIV) have been added (or retained, when already in place). Other countries used mitigation strategies, such as plasma quarantine or pathogen reduction technologies for plasma and/or platelets. CONCLUSION: The experience with gender-neutral donor selection has been largely positive among the countries covered herein and seems to be acceptable to stakeholders, donors and staff. The post-implementation surveillance data collected so far appear reassuring with regards to safety, although longer observation periods are necessary. The putative risks associated with HIV antiretrovirals should be further investigated.
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Infecções por HIV , Minorias Sexuais e de Gênero , Humanos , Masculino , Feminino , Homossexualidade Masculina , Seleção de Pacientes , Infecções por HIV/epidemiologia , Doadores de Sangue , Comportamento Sexual , Seleção do DoadorRESUMO
INTRODUCTION: Homicide is a leading cause of death for American children. We hypothesized demographics and homicide circumstances would differ by victim age. METHODS: We performed a retrospective analysis of the 2003-2020 National Violent Death Reporting System. The National Violent Death Reporting System collects data from nearly all 50 states, the District of Columbia, and Puerto Rico. Demographics (age, sex, race, and ethnicity), homicide year, and weapon type were abstracted. Inclusion criteria were pediatric victims (age < 18). Two groups: 0-4 y old (young cohort [YC]) and 13-17 y old (teen cohort [TC]) were compared. Chi-squared tests, p-test, and t-tests with significance P < 0.05 were used to determine the association between victim demographics, cohort, and homicide mechanism. RESULTS: 10,569 pediatric (male: 70.2% [n = 7424], median age: 12 y old [interquartile range 1-16], black: 52.7% [n = 5573]) homicides met inclusion. Homicides demonstrated a bimodal age distribution (YC: 40.9% [n = 4320] versus TC: 48.9% [n = 5164]). Gender and race were both associated with homicide victimhood (P < 0.001). TC homicides were more likely to be male (YC: 57.8% [n = 2496] versus TC: 83.7% [n = 4320], P < 0.001) and black (YC: 40.1% [n = 1730] versus TC: 65.0% [n = 3357], P < 0.001). Pediatric homicides increased from 2018 (n = 1049) to 2020 (n = 1597), with only TC demonstrating a significant increase (2018: n = 522 versus 2020: n = 971, P < 0.001). Homicide mechanism was significantly associated with age (Blunt: YC: 57.5% [n = 2484] versus TC: 2.9% [n = 148], P < 0.001; Penetrating: YC: 7.9% [n = 340] versus TC: 92.8% [n = 4794], P < 0.001). CONCLUSIONS: Pediatric homicides demonstrate distinct demographic characteristics and homicide mechanisms between two at risk age cohorts. Age-based education and intervention strategies may increase injury prevention programs' efficacy.
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BACKGROUND: Worldwide wheat production is under constant threat by fast-evolving fungal pathogens. In the last decades, wheat breeding for disease resistance heavily relied on the introgression of chromosomal segments from related species as genetic sources of new resistance. The Pm8 resistance gene against the powdery mildew disease has been introgressed from rye into wheat as part of a large 1BL.1RS chromosomal translocation encompassing multiple disease resistance genes and yield components. Due to its high agronomic value, this translocation has seen continuous global use since the 1960s on large growth areas, even after Pm8 resistance was overcome by the powdery mildew pathogen. The long-term use of Pm8 at a global scale provided the unique opportunity to study the consequences of such extensive resistance gene application on pathogen evolution. RESULTS: Using genome-wide association studies in a population of wheat mildew isolates, we identified the avirulence effector AvrPm8 specifically recognized by Pm8. Haplovariant mining in a global mildew population covering all major wheat growing areas of the world revealed 17 virulent haplotypes of the AvrPm8 gene that grouped into two functional categories. The first one comprised amino acid polymorphisms at a single position along the AvrPm8 protein, which we confirmed to be crucial for the recognition by Pm8. The second category consisted of numerous destructive mutations to the AvrPm8 open reading frame such as disruptions of the start codon, gene truncations, gene deletions, and interference with mRNA splicing. With the exception of a single, likely ancient, gain-of-virulence mutation found in mildew isolates around the world, all AvrPm8 virulence haplotypes were found in geographically restricted regions, indicating that they occurred recently as a consequence of the frequent Pm8 use. CONCLUSIONS: In this study, we show that the broad and prolonged use of the Pm8 gene in wheat production worldwide resulted in a multitude of gain-of-virulence mechanisms affecting the AvrPm8 gene in the wheat powdery mildew pathogen. Based on our findings, we conclude that both standing genetic variation as well as locally occurring new mutations contributed to the global breakdown of the Pm8 resistance gene introgression.
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Ascomicetos , Triticum , Triticum/genética , Triticum/microbiologia , Resistência à Doença/genética , Estudo de Associação Genômica Ampla , Melhoramento Vegetal , Ascomicetos/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologiaRESUMO
BACKGROUND: Zika virus (ZIKV) epidemics with infections in pregnant women are associated with severe neurological disease in newborns. Although an arbovirus, ZIKV is also blood transfusion-transmitted (TT). Greater knowledge of the efficiency of ZIKV TT would aid decisions on testing and pathogen reduction technologies (PRT). STUDY DESIGN AND METHODS: Plasma units from ZIKV RNA-reactive blood donors were used to study infectivity in vitro, in mice, and in macaques. Furthermore, plasma units were subjected to PRT using amotosalen/ultraviolet light A (A/UVA) before transfusion. RESULTS: In vitro infectivity of ZIKV RNA-reactive plasma varied between 100 and 1000 international units (IU) of ZIKV RNA. Immunodeficient mice were more sensitive with as low as 32 IU sufficient to infect 50% of mice. 50-5500 IU of RNA led to TT in macaques using dose escalation of three different RNA-positive, seronegative plasma units. In contrast, RNA-reactive units collected postseroconversion were not infectious in macaques, even at a dose of 9 million IU RNA. After A/UVA PRT, transfusion of plasma containing up to 18 million IU was no longer infectious in vitro and did not result in ZIKV TT in macaques. CONCLUSION: Significant risks of ZIKV TT are likely confined to a relatively short viremic window before seroconversion, and that sensitive nucleic acid amplification testing likely identifies the majority of infectious plasma. PRT was demonstrated to be effective at preventing ZIKV TT. Considering that there is no approved ZIKV vaccine, these data are relevant to mitigate the risk of TT during the future ZIKV outbreaks.
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Infecção por Zika virus , Zika virus , Animais , Feminino , Humanos , Camundongos , Gravidez , Transfusão de Componentes Sanguíneos , Transfusão de Sangue , Plasma , RNA Viral , Zika virus/genética , Infecção por Zika virus/epidemiologiaRESUMO
Changes in testing behaviors and reporting requirements have hampered the ability to estimate the U.S. SARS-CoV-2 incidence (1). Hybrid immunity (immunity derived from both previous infection and vaccination) has been reported to provide better protection than that from infection or vaccination alone (2). To estimate the incidence of infection and the prevalence of infection- or vaccination-induced antibodies (or both), data from a nationwide, longitudinal cohort of blood donors were analyzed. During the second quarter of 2021 (April-June), an estimated 68.4% of persons aged ≥16 years had infection- or vaccination-induced SARS-CoV-2 antibodies, including 47.5% from vaccination alone, 12.0% from infection alone, and 8.9% from both. By the third quarter of 2022 (July-September), 96.4% had SARS-CoV-2 antibodies from previous infection or vaccination, including 22.6% from infection alone and 26.1% from vaccination alone; 47.7% had hybrid immunity. Prevalence of hybrid immunity was lowest among persons aged ≥65 years (36.9%), the group with the highest risk for severe disease if infected, and was highest among those aged 16-29 years (59.6%). Low prevalence of infection-induced and hybrid immunity among older adults reflects the success of public health infection prevention efforts while also highlighting the importance of older adults staying up to date with recommended COVID-19 vaccination, including at least 1 bivalent dose.*,.
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COVID-19 , SARS-CoV-2 , Humanos , Idoso , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Doadores de Sangue , Incidência , Estudos Soroepidemiológicos , Anticorpos Antivirais , VacinaçãoRESUMO
The need for huge data sets represents a bottleneck for the application of artificial intelligence. Substantially fewer annotated target lesions than normal tissues for comparison present an additional problem in the field of pathology. Organic brains overcome these limitations by utilizing large numbers of specialized neural nets arranged in both linear and parallel fashion, with each solving a restricted classification problem. They rely on local Hebbian error corrections as compared to the nonlocal back-propagation used in most artificial neural nets, and leverage reinforcement. For these reasons, even toddlers are able to classify objects after only a few examples. Rather than provide an overview of current AI research in pathology, this review focuses on general strategies for overcoming the data bottleneck. These include transfer learning, zero-shot learning, Siamese networks, one-class models, generative networks, and reinforcement learning. Neither an extensive mathematic background nor advanced programing skills are needed to make these subjects accessible to pathologists. However, some familiarity with the basic principles of deep learning, briefly reviewed here, is expected to be useful in understanding both the current limitations of machine learning and determining ways to address them.