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1.
J Bone Joint Surg Am ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954643

RESUMO

BACKGROUND: The Short Musculoskeletal Function Assessment (SMFA) is a well validated, widely used patient-reported outcome (PRO) measure for orthopaedic patients. Despite its widespread use and acceptance, this measure does not have an agreed upon minimal clinically important difference (MCID). The purpose of the present study was to create distributional MCIDs with use of a large cohort of research participants with severe lower extremity fractures. METHODS: Three distributional approaches were used to calculate MCIDs for the Dysfunction and Bother Indices of the SMFA as well as all its domains: (1) half of the standard deviation (one-half SD), (2) twice the standard error of measurement (2SEM), and (3) minimal detectable change (MDC). In addition to evaluating by patient characteristics and the timing of assessment, we reviewed these calculations across several injury groups likely to affect functional outcomes. RESULTS: A total of 4,298 SMFA assessments were collected from 3,185 patients who had undergone surgical treatment of traumatic injuries of the lower extremity at 60 Level-I trauma centers across 7 multicenter, prospective clinical studies. Depending on the statistical approach used, the MCID associated with the overall sample ranged from 7.7 to 10.7 for the SMFA Dysfunction Index and from 11.0 to 16.8 for the SMFA Bother Index. For the Dysfunction Index, the variability across the scores was small (<5%) within the sex and age subgroups but was modest (12% to 18%) across subgroups related to assessment timing. CONCLUSIONS: A defensible MCID can be found between 7 and 11 points for the Dysfunction Index and between 11 and 17 points for the Bother Index. The precise choice of MCID may depend on the preferred statistical approach and the population under study. While differences exist between MCID values based on the calculation method, values were consistent across the categories of the various subgroups presented. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

2.
Proc Biol Sci ; 291(2026): 20240980, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38981521

RESUMO

Ecological and evolutionary predictions are being increasingly employed to inform decision-makers confronted with intensifying pressures on biodiversity. For these efforts to effectively guide conservation actions, knowing the limit of predictability is pivotal. In this study, we provide realistic expectations for the enterprise of predicting changes in ecological and evolutionary observations through time. We begin with an intuitive explanation of predictability (the extent to which predictions are possible) employing an easy-to-use metric, predictive power PP(t). To illustrate the challenge of forecasting, we then show that among insects, birds, fishes and mammals, (i) 50% of the populations are predictable at most 1 year in advance and (ii) the median 1-year-ahead predictive power corresponds to a prediction R 2 of only 20%. Predictability is not an immutable property of ecological systems. For example, different harvesting strategies can impact the predictability of exploited populations to varying degrees. Moreover, incorporating explanatory variables, accounting for time trends and considering multivariate time series can enhance predictability. To effectively address the challenge of biodiversity loss, researchers and practitioners must be aware of the information within the available data that can be used for prediction and explore efficient ways to leverage this knowledge for environmental stewardship.


Assuntos
Biodiversidade , Evolução Biológica , Conservação dos Recursos Naturais , Animais , Aves/fisiologia , Peixes/fisiologia , Insetos/fisiologia , Previsões , Mamíferos , Dinâmica Populacional , Modelos Biológicos
3.
Cell Rep ; 43(7): 114486, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38990718

RESUMO

Skin/soft tissue infections (SSTIs) caused by methicillin-resistant Staphylococcus aureus (MRSA) pose a major healthcare burden. Distinct inflammatory and resolution phases comprise the host immune response to SSTIs. Resolution is a myeloid PPARγ-dependent anti-inflammatory phase that is essential for the clearance of MRSA. However, the signals activating PPARγ to induce resolution remain unknown. Here, we demonstrate that myeloid glucose transporter 1 (GLUT-1) is essential for the onset of resolution. MRSA-challenged macrophages are unsuccessful in generating an oxidative burst or immune radicals in the absence of GLUT-1 due to a reduction in the cellular NADPH pool. This translates in vivo as a significant reduction in lipid peroxidation products required for the activation of PPARγ in MRSA-infected mice lacking myeloid GLUT-1. Chemical induction of PPARγ during infection circumvents this GLUT-1 requirement and improves resolution. Thus, GLUT-1-dependent oxidative burst is essential for the activation of PPARγ and subsequent resolution of SSTIs.

4.
Phys Rev Lett ; 132(24): 241001, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38949363

RESUMO

Standard rulers such as the baryon acoustic oscillation (BAO) scale serve as workhorses for precision tests of cosmology, enabling distance measurements that probe the geometry and expansion history of our Universe. Aside from BAO measurements from the cosmic microwave background (CMB), most standard ruler techniques operate at relatively low redshifts and depend on biased tracers of the matter density field. In a companion paper [H. Fronenberg, A. S. Maniyar, A. R. Pullen, and A. C. Liu, companion paper, Phys. Rev. D 109, 123518 (2024).PRVDAQ2470-001010.1103/PhysRevD.109.123518], we explored the scientific reach of nulling estimators, where CMB lensing convergence maps are cross-correlated with linear combinations of similar maps from line intensity mapping to precisely null out the low-redshift contributions to CMB lensing. We showed that nulling estimators can be used to constrain the high redshift matter power spectrum and that this spectrum exhibits discernible BAO features. Here we propose using these features as a standard ruler at high redshifts that does not rely on biased tracers. Forecasting such a measurement at z∼5, we find that next-generation instruments will be able to constrain the BAO scale to 7.2% precision, while our futuristic observing scenario can constrain the BAO scale to 4% precision. This constitutes a fundamentally new kind of BAO measurement during early epochs in our cosmic history.

5.
Oecologia ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38951222

RESUMO

Competing species may show positive correlations in abundance through time and space if they rely on a shared resource. Such positive correlations might obscure resource partitioning that facilitates competitor coexistence. Here, we examine the potential for resource partitioning between two ecologically similar midge species (Diptera: Chironomidae) in Lake Mývatn, Iceland. Tanytarsus gracilentus and Chironomus islandicus show large, roughly synchronized population fluctuations, implying potential reliance on a shared fluctuating resource and thereby posing the question of how these species coexist at high larval abundances. We first considered spatial partitioning of larvae. Abundances of both species were positively correlated in space; thus, spatial partitioning across different sites in the lake did not appear to be strong. We then inferred differences in dietary resources with stable carbon isotopes. T. gracilentus larvae had significantly higher δ13C values than C. islandicus, suggesting interspecific differences in resource use. Differences in resource selectivity, tube-building behavior, and feeding styles may facilitate resource partitioning between these species. Relative to surface sediments, T. gracilentus had higher δ13C values, suggesting that they selectively graze on 13C-enriched resources such as productive algae from the surface of their tubes. In contrast, C. islandicus had lower δ13C values than surface sediments, suggesting reliance on 13C-depleted resources that may include detrital organic matter and associated microbes that larvae selectively consume from the sediment surface or within their burrow walls. Overall, our study illustrates that coexisting and ecologically similar species may show positive correlations in space and time while using different resources at fine spatial scales.

6.
Ecol Appl ; : e3009, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38978401

RESUMO

Agricultural habitats are frequently disturbed, and disturbances could have major effects on species in upper trophic levels such as hymenopteran parasitoids that are important for biological control. A strategy for conservation biological control is to provide a diversified agricultural landscape which increases the availability of resources such as sugar required by parasitoid biological control agents. Here, we ask whether parasitoids occurring in agriculture benefit from sugar resources more or less than parasitoids occurring in natural habitats surrounding agricultural fields. We collected parasitoids from agricultural alfalfa fields, field margins, and natural prairies, and in the lab we randomly divided them into two treatments: half were given a constant supply of a sugar source to test their residual lifespan, and half were given neither sugar nor water to test their hardiness. Collected individuals were monitored daily and their day of death recorded. Parasitoids receiving a sugar source lived substantially longer than those without. Parasitoids collected in prairies lived longer than those from alfalfa fields in both the residual lifespan and hardiness treatments, with parasitoids from field margins being intermediate between them. Furthermore, the benefits of a sugar source to increase longevity was lower for parasitoids collected in agriculture than in natural habitats. This suggests that, even though parasitoid biological control agents benefit from sugar resources, their short lifespans make the benefit of sugar resources small compared to parasitoids that occur in natural habitats and have longer lifespans, and are adapted to consistent sugar sources.

7.
Drug Saf ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39008024

RESUMO

BACKGROUND AND OBJECTIVE: Upadacitinib is indicated for diseases affecting persons of childbearing potential including rheumatoid arthritis, psoriatic arthritis, axial spondyloarthritis, atopic dermatitis, Crohn's disease, and ulcerative colitis; however, teratogenicity was observed in animal studies. Given the potential for human fetal risk, pregnancy avoidance measures were required during clinical trials. This analysis describes pregnancy outcomes in patients exposed to upadacitinib during pregnancy. METHODS: Clinical trial and postmarketing cases of in utero exposure to upadacitinib were identified in AbbVie's safety database through 25 April, 2023. Analysis of clinical trial cases and postmarketing reports are presented separately; prospective and retrospectively reported pregnancy outcomes are integrated for each. Descriptive rates are presented to summarize outcomes. RESULTS: There were 128 maternal upadacitinib-exposed pregnancies with known outcomes identified; 80 and 48 pregnancies were reported in clinical trials and the postmarketing setting, respectively. In clinical trials (mean in utero exposure of 5 weeks, 3 days), live births (54%), spontaneous abortions (24%), elective terminations (21%), and ectopic pregnancy (1%) were reported. There was one report of a congenital malformation: a 35-week infant with an atrial septal defect. In postmarketing cases, live births (46%), spontaneous abortions (38%), elective terminations (15%), and ectopic pregnancy (2%) were reported. CONCLUSIONS: As the data are limited for in utero exposure to upadacitinib, definitive conclusions cannot be drawn regarding the effect of upadacitinib on pregnancy outcomes. Rates of adverse pregnancy outcomes with upadacitinib exposure were comparable to rates observed in the general population or patients with autoimmune inflammatory diseases. To date, no apparent evidence of teratogenicity exists in the analyses of human pregnancies exposed to upadacitinib during the first trimester.

10.
Organometallics ; 43(13): 1490-1501, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38993820

RESUMO

In this article, we report the development of ruthenium-catalyzed hydrogenolysis of epoxides to selectively give the branched (Markovnikov) alcohol products. In contrast to previously reported catalysts, the use of Milstein's PNN-pincer-ruthenium complex at room temperature allows the conversion of enantiomerically enriched epoxides to secondary alcohols without racemization of the product. The catalyst is effective for a range of aryl epoxides, alkyl epoxides, and glycidyl ethers and is the first homogeneous system to selectively promote hydrogenolysis of glycidol to 1,2-propanediol, without loss of enantiomeric purity. A detailed mechanistic study was conducted, including experimental observations of catalyst speciation under catalytically relevant conditions, comprehensive kinetic characterization of the catalytic reaction, and computational analysis via density functional theory. Heterolytic hydrogen cleavage is mediated by the ruthenium center and exogenous alkoxide base. Epoxide ring opening occurs through an opposite-side attack of the ruthenium hydride on the less-hindered epoxide carbon, giving the branched alcohol product selectively.

11.
Acta Physiol (Oxf) ; : e14197, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38958262

RESUMO

AIM: How the cerebral metabolic rates of oxygen and glucose utilization (CMRO2 and CMRGlc, respectively) are affected by alterations in arterial PCO2 (PaCO2) is equivocal and therefore was the primary question of this study. METHODS: This retrospective analysis involved pooled data from four separate studies, involving 41 healthy adults (35 males/6 females). Participants completed stepwise steady-state alterations in PaCO2 ranging between 30 and 60 mmHg. The CMRO2 and CMRGlc were assessed via the Fick approach (CBF × arterial-internal jugular venous difference of oxygen or glucose content, respectively) utilizing duplex ultrasound of the internal carotid artery and vertebral artery to calculate cerebral blood flow (CBF). RESULTS: The CMRO2 was altered by 0.5 mL × min-1 (95% CI: -0.6 to -0.3) per mmHg change in PaCO2 (p < 0.001) which corresponded to a 9.8% (95% CI: -13.2 to -6.5) change in CMRO2 with a 9 mmHg change in PaCO2 (inclusive of hypo- and hypercapnia). The CMRGlc was reduced by 7.7% (95% CI: -15.4 to -0.08, p = 0.045; i.e., reduction in net glucose uptake) and the oxidative glucose index (ratio of oxygen to glucose uptake) was reduced by 5.6% (95% CI: -11.2 to 0.06, p = 0.049) with a + 9 mmHg increase in PaCO2. CONCLUSION: Collectively, the CMRO2 is altered by approximately 1% per mmHg change in PaCO2. Further, glucose is incompletely oxidized during hypercapnia, indicating reductions in CMRO2 are either met by compensatory increases in nonoxidative glucose metabolism or explained by a reduction in total energy production.

12.
Environ Microbiol ; 26(6): e16660, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38822592

RESUMO

Over 6 years, we conducted an extensive survey of spontaneous grape fermentations, examining 3105 fungal microbiomes across 14 distinct grape-growing regions. Our investigation into the biodiversity of these fermentations revealed that a small number of highly abundant genera form the core of the initial grape juice microbiome. Consistent with previous studies, we found that the region of origin had the most significant impact on microbial diversity patterns. We also discovered that certain taxa were consistently associated with specific geographical locations and grape varieties, although these taxa represented only a minor portion of the overall diversity in our dataset. Through unsupervised clustering and dimensionality reduction analysis, we identified three unique community types, each exhibiting variations in the abundance of key genera. When we projected these genera onto global branches, it suggested that microbiomes transition between these three broad community types. We further investigated the microbial community composition throughout the fermentation process. Our observations indicated that the initial microbial community composition could predict the diversity during the early stages of fermentation. Notably, Hanseniaspora uvarum emerged as the primary non-Saccharomyces species within this large collection of samples.


Assuntos
Biodiversidade , Fermentação , Fungos , Micobioma , Vitis , Vitis/microbiologia , Fungos/classificação , Fungos/genética , Fungos/metabolismo , Fungos/isolamento & purificação , Microbiota
13.
Molecules ; 29(12)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38930871

RESUMO

Synthetic efforts toward complex natural product (NP) scaffolds are useful ones, particularly those aimed at expanding their bioactive chemical space. Here, we utilised an orthogonal cheminformatics-based approach to predict the potential biological activities for a series of synthetic bis-indole alkaloids inspired by elusive sponge-derived NPs, echinosulfone A (1) and echinosulfonic acids A-D (2-5). Our work includes the first synthesis of desulfato-echinosulfonic acid C, an α-hydroxy bis(3'-indolyl) alkaloid (17), and its full NMR characterisation. This synthesis provides corroborating evidence for the structure revision of echinosulfonic acids A-C. Additionally, we demonstrate a robust synthetic strategy toward a diverse range of α-methine bis(3'-indolyl) acids and acetates (11-16) without the need for silica-based purification in either one or two steps. By integrating our synthetic library of bis-indoles with bioactivity data for 2048 marine indole alkaloids (reported up to the end of 2021), we analyzed their overlap with marine natural product chemical diversity. Notably, the C-6 dibrominated α-hydroxy bis(3'-indolyl) and α-methine bis(3'-indolyl) analogues (11, 14, and 17) were found to contain significant overlap with antibacterial C-6 dibrominated marine bis-indoles, guiding our biological evaluation. Validating the results of our cheminformatics analyses, the dibrominated α-methine bis(3'-indolyl) alkaloids (11, 12, 14, and 15) were found to exhibit antibacterial activities against methicillin-sensitive and -resistant Staphylococcus aureus. Further, while investigating other synthetic approaches toward bis-indole alkaloids, 16 incorrectly assigned synthetic α-hydroxy bis(3'-indolyl) alkaloids were identified. After careful analysis of their reported NMR data, and comparison with those obtained for the synthetic bis-indoles reported herein, all of the structures have been revised to α-methine bis(3'-indolyl) alkaloids.


Assuntos
Antibacterianos , Quimioinformática , Alcaloides Indólicos , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Alcaloides Indólicos/química , Alcaloides Indólicos/farmacologia , Alcaloides Indólicos/síntese química , Quimioinformática/métodos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Produtos Biológicos/síntese química
14.
Dev Med Child Neurol ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38840441

RESUMO

First-line genetic investigations for rare neurological and developmental conditions have limitations in their ability to detect and characterize copy number variants (CNVs). Whole genome sequencing (WGS) offers potential advantages over other methods of CNV analysis. We aimed to demonstrate the utility of CNV detection using WGS through description of three clinical cases. WGS analysis was undertaken in three patients presenting to a national rare disease service, in whom a genetic aetiology remained uncertain after gene panel testing or microarray based comparative genomic hybridization (array CGH). In all three cases, WGS identified CNVs and confirmed zygosity and pathogenicity, resulting in genetic diagnoses of PRKN-related Parkinson disease, TAOK1-related neurodevelopmental disorder, and AP1G1-related Usmani-Riazuddin syndrome. This case series demonstrates the value of WGS analysis in identifying or better characterizing CNVs that were missed or deemed of uncertain significance using conventional methods of testing. Importantly, our approach facilitated accurate genetic diagnosis and counselling for the families involved.

15.
Schizophr Res ; 270: 63-67, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38865807

RESUMO

Young people who are at clinical high-risk for psychosis experience suicidal thoughts and behaviors at a greater rate than young people in the general population. However, no suicide prevention interventions have been specifically designed for or tested with this group of young people. To address this gap, we need to identify and leverage malleable potential intervention targets that can be measured at multiple levels of analysis. Here, we argue that social network structure, or the pattern of relationships in which a person is embedded, offers one potential target for intervention. We first provide a select review of what is currently known about social network structure and suicide risk, social network disruption among people at clinical high-risk for psychosis, and inflammatory processes as a potential underlying metric of social bond disruption. We then propose opportunities to advance suicide prevention research focused on young people at clinical high-risk for psychosis, with an eye toward establishing a foundation for future interventions that can account for biological, psychological, and social domains.

16.
Res Sq ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38826306

RESUMO

Background: Neurodegenerative tauopathies may progress based on seeding by pathological tau assemblies, whereby an aggregate is released from one cell, gains entry to an adjacent or connected cell, and serves as a specific template for its own replication in the cytoplasm. In vitro seeding reactions typically take days, yet seeding into the complex cytoplasmic milieu happens within hours, implicating a machinery with unknown players that controls this process in the acute phase. Methods: We used proximity labeling to identify factors that control seed amplification within 5h of seed exposure. We fused split-APEX2 to the C-terminus of tau repeat domain (RD) to reconstitute peroxidase activity 5h after seeded intracellular tau aggregation. Valosin containing protein (VCP/p97) was the top hit. VCP harbors dominant mutations that underlie two neurodegenerative diseases, multisystem proteinopathy and vacuolar tauopathy, but its mechanistic role is unclear. We used immortalized cells and human neurons to study the effects of VCP on tau seeding. We exposed cells to fibrils or brain homogenates in cell culture media and measured effects on uptake and induction of intracellular tau aggregation following various genetic and chemical manipulations of VCP. Results: VCP knockdown reduced tau seeding. Chemical inhibitors had opposing effects on aggregation in HEK293T tau biosensor cells and human neurons alike: ML-240 increased seeding efficiency, whereas NMS-873 decreased it. The inhibitors were effective only when administered within 8h of seed exposure, indicating a role for VCP early in seed processing. We screened 30 VCP co-factors in HEK293T biosensor cells by genetic knockout or knockdown. Reduction of ATXN3, NSFL1C, UBE4B, NGLY1, and OTUB1 decreased tau seeding, as did NPLOC4, which also uniquely increased soluble tau levels. By contrast, reduction of FAF2 increased tau seeding. Conclusions: Divergent effects on tau seeding of chemical inhibitors and cofactor reduction indicate that VCP regulates this process. This is consistent with a dedicated cytoplasmic processing complex based on VCP that directs seeds acutely towards degradation vs. amplification.

17.
Sci Adv ; 10(25): eadl6153, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38896608

RESUMO

Platelet-producing megakaryocytes (MKs) primarily reside in the bone marrow, where they duplicate their DNA content with each cell cycle resulting in polyploid cells with an intricate demarcation membrane system. While key elements of the cytoskeletal reorganizations during proplatelet formation have been identified, what initiates the release of platelets into vessel sinusoids remains largely elusive. Using a cell cycle indicator, we observed a unique phenomenon, during which amplified centrosomes in MKs underwent clustering following mitosis, closely followed by proplatelet formation, which exclusively occurred in G1 of interphase. Forced cell cycle arrest in G1 increased proplatelet formation not only in vitro but also in vivo following short-term starvation of mice. We identified that inhibition of the centrosomal protein kinesin family member C1 (KIFC1) impaired clustering and subsequent proplatelet formation, while KIFC1-deficient mice exhibited reduced platelet counts. In summary, we identified KIFC1- and cell cycle-mediated centrosome clustering as an important initiator of proplatelet formation from MKs.


Assuntos
Plaquetas , Ciclo Celular , Centrossomo , Cinesinas , Megacariócitos , Centrossomo/metabolismo , Animais , Megacariócitos/metabolismo , Megacariócitos/citologia , Camundongos , Plaquetas/metabolismo , Cinesinas/metabolismo , Cinesinas/genética , Camundongos Knockout , Humanos , Mitose
18.
bioRxiv ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38826482

RESUMO

Background: The cardinal feature of systemic sclerosis (SSc) is skin thickening and tightening. Targetable mechanisms for skin features remain elusive. Drugs successful in treating internal organ manifestations have failed efficacy in skin. Dermal white adipose tissue (DWAT) is amongst the understudied contributors to skin manifestations. This study proposes the role of sine oculis homeobox homolog 1 (SIX1), a gene previously unrecognized as a contributor to dermal lipoatrophy characteristic of early skin fibrosis in SSc. Methods: Skin gene expression of SIX1 was analyzed in the GENISOS and PRESS SSc cohorts. Correlation analysis was performed with Spearman rank analysis. Novel mouse models were developed using the Cre-loxp system to knock out Six1 in all cells and mature adipocytes. Subcutaneous bleomycin was used to model early DWAT atrophy and dermal fibrosis characteristic of SSc. Findings: SIX1 was upregulated in SSc skin, the expression of which correlates with adipose-associated genes and molecular pathways. Genetic deletion of Six1 in all cells in mice challenged with bleomycin abrogated end-stage fibrotic gene expression and dermal adipocyte shrinkage. Adipocyte specific Six1 deletion was able to attenuate the early increase in skin thickness, a hallmark of experimental skin fibrosis. Further studies revealed a link between elevated SIX1 and increased expression of SERPINE1 and its protein PAI-1 which are known pro-fibrotic mediators. Interpretation: This work identifies SIX1 as an early marker of skin fibrosis in SSc. We also demonstrate a causative role of Six1 in skin fibrosis by promoting adipocyte loss and show that deletion of Six1 in adipocytes has the potential of impacting early disease progression.

19.
Infect Immun ; 92(7): e0015224, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38888310

RESUMO

The major gram-positive pathogen group A Streptococcus (GAS) is a model organism for studying microbial epidemics as it causes waves of infections. Since 1980, several GAS epidemics have been ascribed to the emergence of clones producing increased amounts of key virulence factors such as streptolysin O (SLO). Herein, we sought to identify mechanisms underlying our recently identified temporal clonal emergence among emm4 GAS, given that emergent strains did not produce augmented levels of virulence factors relative to historic isolates. By creating and analyzing isoallelic strains, we determined that a conserved mutation in a previously undescribed gene encoding a putative carbonic anhydrase was responsible for the defective in vitro growth observed in the emergent strains. We also identified that the emergent strains survived better inside macrophages and killed macrophages at lower rates than the historic strains. Via the creation of isogenic mutant strains, we linked the emergent strain "survival" phenotype to the downregulation of the SLO encoding gene and upregulation of the msrAB operon which encodes proteins involved in defense against extracellular oxidative stress. Our findings are in accord with recent surveillance studies which found a high ratio of mucosal (i.e., pharyngeal) relative to invasive infections among emm4 GAS. Since ever-increasing virulence is unlikely to be evolutionarily advantageous for a microbial pathogen, our data further understanding of the well-described oscillating patterns of virulent GAS infections by demonstrating mechanisms by which emergent strains adapt a "survival" strategy to outcompete previously circulating isolates.


Assuntos
Proteínas de Bactérias , Macrófagos , Infecções Estreptocócicas , Streptococcus pyogenes , Estreptolisinas , Fatores de Virulência , Streptococcus pyogenes/genética , Streptococcus pyogenes/patogenicidade , Streptococcus pyogenes/imunologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/mortalidade , Humanos , Macrófagos/microbiologia , Macrófagos/imunologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Estreptolisinas/genética , Estreptolisinas/metabolismo , Fatores de Virulência/genética , Mutação , Interações Hospedeiro-Patógeno/imunologia , Virulência/genética , Animais , Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Antígenos de Bactérias/imunologia , Viabilidade Microbiana , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Camundongos , Regulação Bacteriana da Expressão Gênica , Proteínas de Transporte
20.
medRxiv ; 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38854118

RESUMO

Background: Transparency can build trust in the scientific process, but scientific findings can be undermined by poor and obscure data use and reporting practices. The purpose of this work is to report how data from the Adolescent Brain Cognitive Development (ABCD) Study has been used to date, and to provide practical recommendations on how to improve the transparency and reproducibility of findings. Methods: Articles published from 2017 to 2023 that used ABCD Study data were reviewed using more than 30 data extraction items to gather information on data use practices. Total frequencies were reported for each extraction item, along with computation of a Level of Completeness (LOC) score that represented overall endorsement of extraction items. Univariate linear regression models were used to examine the correlation between LOC scores and individual extraction items. Post hoc analysis included examination of whether LOC scores were correlated with the logged 2-year journal impact factor. Results: There were 549 full-length articles included in the main analysis. Analytic scripts were shared in 30% of full-length articles. The number of participants excluded due to missing data was reported in 60% of articles, and information on missing data for individual variables (e.g., household income) was provided in 38% of articles. A table describing the analytic sample was included in 83% of articles. A race and/or ethnicity variable was included in 78% of reviewed articles, while its inclusion was justified in only 41% of these articles. LOC scores were highly correlated with extraction items related to examination of missing data. A bottom 10% of LOC score was significantly correlated with a lower logged journal impact factor when compared to the top 10% of LOC scores (ß=-0.77, 95% -1.02, -0.51; p-value < 0.0001). Conclusion: These findings highlight opportunities for improvement in future papers using ABCD Study data to readily adapt analytic practices for better transparency and reproducibility efforts. A list of recommendations is provided to facilitate adherence in future research.

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