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1.
Mol Cell ; 78(6): 1237-1251.e7, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32442397

RESUMO

DNA replication stress can stall replication forks, leading to genome instability. DNA damage tolerance pathways assist fork progression, promoting replication fork reversal, translesion DNA synthesis (TLS), and repriming. In the absence of the fork remodeler HLTF, forks fail to slow following replication stress, but underlying mechanisms and cellular consequences remain elusive. Here, we demonstrate that HLTF-deficient cells fail to undergo fork reversal in vivo and rely on the primase-polymerase PRIMPOL for repriming, unrestrained replication, and S phase progression upon limiting nucleotide levels. By contrast, in an HLTF-HIRAN mutant, unrestrained replication relies on the TLS protein REV1. Importantly, HLTF-deficient cells also exhibit reduced double-strand break (DSB) formation and increased survival upon replication stress. Our findings suggest that HLTF promotes fork remodeling, preventing other mechanisms of replication stress tolerance in cancer cells. This remarkable plasticity of the replication fork may determine the outcome of replication stress in terms of genome integrity, tumorigenesis, and response to chemotherapy.


Assuntos
Replicação do DNA/fisiologia , Proteínas de Ligação a DNA/metabolismo , DNA/biossíntese , Fatores de Transcrição/metabolismo , Linhagem Celular Tumoral , DNA/genética , Dano ao DNA/genética , DNA Primase/metabolismo , DNA Primase/fisiologia , Reparo do DNA/genética , Replicação do DNA/genética , Proteínas de Ligação a DNA/genética , DNA Polimerase Dirigida por DNA/metabolismo , DNA Polimerase Dirigida por DNA/fisiologia , Células HEK293 , Humanos , Células K562 , Enzimas Multifuncionais/metabolismo , Enzimas Multifuncionais/fisiologia , Nucleotidiltransferases/metabolismo , Nucleotidiltransferases/fisiologia , Fatores de Transcrição/genética
2.
Cell ; 148(4): 702-15, 2012 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-22341443

RESUMO

Kes1, and other oxysterol-binding protein superfamily members, are involved in membrane and lipid trafficking through trans-Golgi network (TGN) and endosomal systems. We demonstrate that Kes1 represents a sterol-regulated antagonist of TGN/endosomal phosphatidylinositol-4-phosphate signaling. This regulation modulates TOR activation by amino acids and dampens gene expression driven by Gcn4, the primary transcriptional activator of the general amino acid control regulon. Kes1-mediated repression of Gcn4 transcription factor activity is characterized by nonproductive Gcn4 binding to its target sequences, involves TGN/endosome-derived sphingolipid signaling, and requires activity of the cyclin-dependent kinase 8 (CDK8) module of the enigmatic "large Mediator" complex. These data describe a pathway by which Kes1 integrates lipid metabolism with TORC1 signaling and nitrogen sensing.


Assuntos
Endossomos/metabolismo , Metabolismo dos Lipídeos , Nitrogênio/metabolismo , Saccharomyces cerevisiae/metabolismo , Transdução de Sinais , Autofagia , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Regulação Fúngica da Expressão Gênica , Saccharomyces cerevisiae/citologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Esteróis/metabolismo , Fatores de Transcrição/metabolismo
3.
N Engl J Med ; 389(8): 687-699, 2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37486775

RESUMO

BACKGROUND: The risk of cardiovascular disease is increased among persons with human immunodeficiency virus (HIV) infection, so data regarding primary prevention strategies in this population are needed. METHODS: In this phase 3 trial, we randomly assigned 7769 participants with HIV infection with a low-to-moderate risk of cardiovascular disease who were receiving antiretroviral therapy to receive daily pitavastatin calcium (at a dose of 4 mg) or placebo. The primary outcome was the occurrence of a major adverse cardiovascular event, which was defined as a composite of cardiovascular death, myocardial infarction, hospitalization for unstable angina, stroke, transient ischemic attack, peripheral arterial ischemia, revascularization, or death from an undetermined cause. RESULTS: The median age of the participants was 50 years (interquartile range, 45 to 55); the median CD4 count was 621 cells per cubic millimeter (interquartile range, 448 to 827), and the HIV RNA value was below quantification in 5250 of 5997 participants (87.5%) with available data. The trial was stopped early for efficacy after a median follow-up of 5.1 years (interquartile range, 4.3 to 5.9). The incidence of a major adverse cardiovascular event was 4.81 per 1000 person-years in the pitavastatin group and 7.32 per 1000 person-years in the placebo group (hazard ratio, 0.65; 95% confidence interval [CI], 0.48 to 0.90; P = 0.002). Muscle-related symptoms occurred in 91 participants (2.3%) in the pitavastatin group and in 53 (1.4%) in the placebo group; diabetes mellitus occurred in 206 participants (5.3%) and in 155 (4.0%), respectively. CONCLUSIONS: Participants with HIV infection who received pitavastatin had a lower risk of a major adverse cardiovascular event than those who received placebo over a median follow-up of 5.1 years. (Funded by the National Institutes of Health and others; REPRIEVE ClinicalTrials.gov number, NCT02344290.).


Assuntos
Doenças Cardiovasculares , Infecções por HIV , Inibidores de Hidroximetilglutaril-CoA Redutases , Humanos , Pessoa de Meia-Idade , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Método Duplo-Cego , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/prevenção & controle , Quinolinas/efeitos adversos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico
4.
Nucleic Acids Res ; 52(8): 4659-4675, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38554102

RESUMO

RexA and RexB function as an exclusion system that prevents bacteriophage T4rII mutants from growing on Escherichia coli λ phage lysogens. Recent data established that RexA is a non-specific DNA binding protein that can act independently of RexB to bias the λ bistable switch toward the lytic state, preventing conversion back to lysogeny. The molecular interactions underlying these activities are unknown, owing in part to a dearth of structural information. Here, we present the 2.05-Å crystal structure of the λ RexA dimer, which reveals a two-domain architecture with unexpected structural homology to the recombination-associated protein RdgC. Modelling suggests that our structure adopts a closed conformation and would require significant domain rearrangements to facilitate DNA binding. Mutagenesis coupled with electromobility shift assays, limited proteolysis, and double electron-electron spin resonance spectroscopy support a DNA-dependent conformational change. In vivo phenotypes of RexA mutants suggest that DNA binding is not a strict requirement for phage exclusion but may directly contribute to modulation of the bistable switch. We further demonstrate that RexA homologs from other temperate phages also dimerize and bind DNA in vitro. Collectively, these findings advance our mechanistic understanding of Rex functions and provide new evolutionary insights into different aspects of phage biology.


Assuntos
Bacteriófago lambda , Proteínas de Ligação a DNA , Modelos Moleculares , Proteínas Virais , Bacteriófago lambda/genética , Cristalografia por Raios X , Proteínas Virais/metabolismo , Proteínas Virais/química , Proteínas Virais/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Ligação Proteica , Multimerização Proteica , DNA Viral/genética , DNA Viral/metabolismo , Mutação , Lisogenia , Escherichia coli/virologia , Escherichia coli/genética , Escherichia coli/metabolismo , DNA/metabolismo , DNA/química
5.
Proc Natl Acad Sci U S A ; 120(25): e2218127120, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37314935

RESUMO

Reduced nitrogen (N) is central to global biogeochemistry, yet there are large uncertainties surrounding its sources and rate of cycling. Here, we present observations of gas-phase urea (CO(NH2)2) in the atmosphere from airborne high-resolution mass spectrometer measurements over the North Atlantic Ocean. We show that urea is ubiquitous in the lower troposphere in the summer, autumn, and winter but was not detected in the spring. The observations suggest that the ocean is the primary emission source, but further studies are required to understand the responsible mechanisms. Urea is also observed aloft due to long-range transport of biomass-burning plumes. These observations alongside global model simulations point to urea being an important, and currently unaccounted for, component of reduced-N to the remote marine atmosphere. Airborne transfer of urea between nutrient-rich and -poor parts of the ocean can occur readily and could impact ecosystems and oceanic uptake of carbon dioxide, with potentially important climate implications.

6.
J Neurosci ; 44(4)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38050100

RESUMO

What happens once a cortical territory becomes functionally redundant? We studied changes in brain function and behavior for the remaining hand in humans (male and female) with either a missing hand from birth (one-handers) or due to amputation. Previous studies reported that amputees, but not one-handers, show increased ipsilateral activity in the somatosensory territory of the missing hand (i.e., remapping). We used a complex finger task to explore whether this observed remapping in amputees involves recruiting more neural resources to support the intact hand to meet greater motor control demands. Using basic fMRI analysis, we found that only amputees had more ipsilateral activity when motor demand increased; however, this did not match any noticeable improvement in their behavioral task performance. More advanced multivariate fMRI analyses showed that amputees had stronger and more typical representation-relative to controls' contralateral hand representation-compared with one-handers. This suggests that in amputees, both hand areas work together more collaboratively, potentially reflecting the intact hand's efference copy. One-handers struggled to learn difficult finger configurations, but this did not translate to differences in univariate or multivariate activity relative to controls. Additional white matter analysis provided conclusive evidence that the structural connectivity between the two hand areas did not vary across groups. Together, our results suggest that enhanced activity in the missing hand territory may not reflect intact hand function. Instead, we suggest that plasticity is more restricted than generally assumed and may depend on the availability of homologous pathways acquired early in life.


Assuntos
Amputados , Mapeamento Encefálico , Masculino , Humanos , Feminino , Mapeamento Encefálico/métodos , Mãos , Amputação Cirúrgica , Análise e Desempenho de Tarefas , Imageamento por Ressonância Magnética/métodos , Lateralidade Funcional
7.
Circulation ; 149(6): 417-426, 2024 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-37970713

RESUMO

BACKGROUND: Tools for mortality prediction in patients with the severe hypercholesterolemia phenotype (low-density lipoprotein cholesterol ≥190 mg/dL) are limited and restricted to specific racial and ethnic cohorts. We sought to evaluate the predictors of long-term mortality in a large racially and ethnically diverse US patient cohort with low-density lipoprotein cholesterol ≥190 mg/dL. METHODS: We conducted a retrospective analysis of all patients with a low-density lipoprotein cholesterol ≥190 mg/dL seeking care at Montefiore from 2010 through 2020. Patients <18 years of age or with previous malignancy were excluded. The primary end point was all-cause mortality. Analyses were stratified by age, sex, and race and ethnicity. Patients were stratified by primary and secondary prevention. Cox regression analyses were used to adjust for demographic, clinical, and treatment variables. RESULTS: A total of 18 740 patients were included (37% non-Hispanic Black, 30% Hispanic, 12% non-Hispanic White, and 2% non-Hispanic Asian patients). The mean age was 53.9 years, and median follow-up was 5.2 years. Both high-density lipoprotein cholesterol and body mass index extremes were associated with higher mortality in univariate analyses. In adjusted models, higher low-density lipoprotein cholesterol and triglyceride levels were associated with an increased 9-year mortality risk (adjusted hazard ratio [HR], 1.08 [95% CI, 1.05-1.11] and 1.04 [95% CI, 1.02-1.06] per 20-mg/dL increase, respectively). Clinical factors associated with higher mortality included male sex (adjusted HR, 1.31 [95% CI, 1.08-1.58]), older age (adjusted HR, 1.19 per 5-year increase [95% CI, 1.15-1.23]), hypertension (adjusted HR, 2.01 [95% CI, 1.57-2.57]), chronic kidney disease (adjusted HR, 1.68 [95% CI, 1.36-2.09]), diabetes (adjusted HR, 1.79 [95% CI, 1.50-2.15]), heart failure (adjusted HR, 1.51 [95% CI, 1.16-1.95]), myocardial infarction (adjusted HR, 1.41 [95% CI, 1.05-1.90]), and body mass index <20 kg/m2 (adjusted HR, 3.36 [95% CI, 2.29-4.93]). A significant survival benefit was conferred by lipid-lowering therapy (adjusted HR, 0.57 [95% CI, 0.42-0.77]). In the primary prevention group, high-density lipoprotein cholesterol <40 mg/dL was independently associated with higher mortality (adjusted HR, 1.49 [95% CI, 1.06-2.09]). Temporal trend analyses showed a reduction in statin use over time (P<0.001). In the most recent time period (2019-2020), 56% of patients on primary prevention and 85% of those on secondary prevention were on statin therapy. CONCLUSIONS: In a large, diverse cohort of US patients with the severe hypercholesterolemia phenotype, we identified several patient characteristics associated with increased 9-year all-cause mortality and observed a decrease in statin use over time, in particular for primary prevention. Our results support efforts geared toward early recognition and consistent treatment for patients with severe hypercholesterolemia.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Hipercolesterolemia , Humanos , Masculino , Pessoa de Meia-Idade , Hipercolesterolemia/tratamento farmacológico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Estudos Retrospectivos , LDL-Colesterol , HDL-Colesterol , Fenótipo , Fatores de Risco
8.
N Engl J Med ; 386(26): 2459-2470, 2022 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-35709019

RESUMO

BACKGROUND: Intravenous fluids are recommended for the treatment of patients who are in septic shock, but higher fluid volumes have been associated with harm in patients who are in the intensive care unit (ICU). METHODS: In this international, randomized trial, we assigned patients with septic shock in the ICU who had received at least 1 liter of intravenous fluid to receive restricted intravenous fluid or standard intravenous fluid therapy; patients were included if the onset of shock had been within 12 hours before screening. The primary outcome was death from any cause within 90 days after randomization. RESULTS: We enrolled 1554 patients; 770 were assigned to the restrictive-fluid group and 784 to the standard-fluid group. Primary outcome data were available for 1545 patients (99.4%). In the ICU, the restrictive-fluid group received a median of 1798 ml of intravenous fluid (interquartile range, 500 to 4366); the standard-fluid group received a median of 3811 ml (interquartile range, 1861 to 6762). At 90 days, death had occurred in 323 of 764 patients (42.3%) in the restrictive-fluid group, as compared with 329 of 781 patients (42.1%) in the standard-fluid group (adjusted absolute difference, 0.1 percentage points; 95% confidence interval [CI], -4.7 to 4.9; P = 0.96). In the ICU, serious adverse events occurred at least once in 221 of 751 patients (29.4%) in the restrictive-fluid group and in 238 of 772 patients (30.8%) in the standard-fluid group (adjusted absolute difference, -1.7 percentage points; 99% CI, -7.7 to 4.3). At 90 days after randomization, the numbers of days alive without life support and days alive and out of the hospital were similar in the two groups. CONCLUSIONS: Among adult patients with septic shock in the ICU, intravenous fluid restriction did not result in fewer deaths at 90 days than standard intravenous fluid therapy. (Funded by the Novo Nordisk Foundation and others; CLASSIC ClinicalTrials.gov number, NCT03668236.).


Assuntos
Hidratação , Choque Séptico , Administração Intravenosa , Adulto , Cuidados Críticos/métodos , Hidratação/efeitos adversos , Hidratação/métodos , Humanos , Unidades de Terapia Intensiva , Choque Séptico/mortalidade , Choque Séptico/terapia
9.
Arterioscler Thromb Vasc Biol ; 44(2): 513-521, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38152887

RESUMO

BACKGROUND: Leaflet calcification contributes to the development and progression of aortic valve stenosis. Vitamin K activates inhibitors of vascular calcification and may modulate inflammation and skeletal bone loss. Therefore, we aimed to determine whether higher dietary intakes of vitamin K1 are associated with a lower incidence of aortic stenosis. METHODS: In the Danish Diet, Cancer and Health study, participants aged 50 to 64 years completed a 192-item food frequency questionnaire at baseline, from which habitual intakes of vitamin K1 were estimated. Participants were prospectively followed using linkage to nationwide registers to determine incident aortic valve stenosis (primary outcome) and aortic stenosis with subsequent complications (aortic valve replacement, heart failure, or cardiovascular disease-related mortality; secondary outcome). RESULTS: In 55 545 participants who were followed for a maximum of 21.5 years, 1085 were diagnosed with aortic stenosis and 615 were identified as having subsequent complications. Participants in the highest quintile of vitamin K1 intake had a 23% lower risk of aortic stenosis (hazard ratio, 0.77 [95% CI, 0.63-0.94]) and a 27% lower risk of aortic stenosis with subsequent complications (hazard ratio, 0.73 [95% CI, 0.56-0.95]), compared with participants in the lowest quintile after adjusting for demographics and cardiovascular risk factors. CONCLUSIONS: In this study, a high intake of vitamin K1-rich foods was associated with a lower incidence of aortic stenosis and a lower risk of aortic stenosis with subsequent complications.


Assuntos
Estenose da Valva Aórtica , Vitamina K 1 , Humanos , Estenose da Valva Aórtica/epidemiologia , Estenose da Valva Aórtica/cirurgia , Valva Aórtica , Vitamina K , Ingestão de Alimentos , Fatores de Risco , Vitamina K 2
10.
Brain ; 147(6): 2085-2097, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38735647

RESUMO

Biallelic pathogenic variants in the PNPLA6 gene cause a broad spectrum of disorders leading to gait disturbance, visual impairment, anterior hypopituitarism and hair anomalies. PNPLA6 encodes neuropathy target esterase (NTE), yet the role of NTE dysfunction on affected tissues in the large spectrum of associated disease remains unclear. We present a systematic evidence-based review of a novel cohort of 23 new patients along with 95 reported individuals with PNPLA6 variants that implicate missense variants as a driver of disease pathogenesis. Measuring esterase activity of 46 disease-associated and 20 common variants observed across PNPLA6-associated clinical diagnoses unambiguously reclassified 36 variants as pathogenic and 10 variants as likely pathogenic, establishing a robust functional assay for classifying PNPLA6 variants of unknown significance. Estimating the overall NTE activity of affected individuals revealed a striking inverse relationship between NTE activity and the presence of retinopathy and endocrinopathy. This phenomenon was recaptured in vivo in an allelic mouse series, where a similar NTE threshold for retinopathy exists. Thus, PNPLA6 disorders, previously considered allelic, are a continuous spectrum of pleiotropic phenotypes defined by an NTE genotype:activity:phenotype relationship. This relationship, and the generation of a preclinical animal model, pave the way for therapeutic trials, using NTE as a biomarker.


Assuntos
Fenótipo , Animais , Feminino , Humanos , Masculino , Camundongos , Aciltransferases , Hidrolases de Éster Carboxílico/genética , Mutação de Sentido Incorreto , Fosfolipases/genética , Doenças Retinianas/genética
11.
Nature ; 565(7741): 587-593, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30700872

RESUMO

Secondary organic aerosol contributes to the atmospheric particle burden with implications for air quality and climate. Biogenic volatile organic compounds such as terpenoids emitted from plants are important secondary organic aerosol precursors with isoprene dominating the emissions of biogenic volatile organic compounds globally. However, the particle mass from isoprene oxidation is generally modest compared to that of other terpenoids. Here we show that isoprene, carbon monoxide and methane can each suppress the instantaneous mass and the overall mass yield derived from monoterpenes in mixtures of atmospheric vapours. We find that isoprene 'scavenges' hydroxyl radicals, preventing their reaction with monoterpenes, and the resulting isoprene peroxy radicals scavenge highly oxygenated monoterpene products. These effects reduce the yield of low-volatility products that would otherwise form secondary organic aerosol. Global model calculations indicate that oxidant and product scavenging can operate effectively in the real atmosphere. Thus highly reactive compounds (such as isoprene) that produce a modest amount of aerosol are not necessarily net producers of secondary organic particle mass and their oxidation in mixtures of atmospheric vapours can suppress both particle number and mass of secondary organic aerosol. We suggest that formation mechanisms of secondary organic aerosol in the atmosphere need to be considered more realistically, accounting for mechanistic interactions between the products of oxidizing precursor molecules (as is recognized to be necessary when modelling ozone production).

12.
J Am Chem Soc ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622048

RESUMO

In supramolecular materials, multiple weak binding groups can act as a single collective unit when confined to a localized volume, thereby producing strong but dynamic bonds between material building blocks. This principle of multivalency provides a versatile means of controlling material assembly, as both the number and the type of supramolecular moieties become design handles to modulate the strength of intermolecular interactions. However, in materials with building blocks significantly larger than individual supramolecular moieties (e.g., polymer or nanoparticle scaffolds), the degree of multivalency is difficult to predict or control, as sufficiently large scaffolds inherently preclude separated supramolecular moieties from interacting. Because molecular models commonly used to examine supramolecular interactions are intrinsically unable to examine any trends or emergent behaviors that arise due to nanoscale scaffold geometry, our understanding of the thermodynamics of these massively multivalent systems remains limited. Here we address this challenge via the coassembly of polymer-grafted nanoparticles and multivalent polymers, systematically examining how multivalent scaffold size, shape, and spacing affect their collective thermodynamics. Investigating the interplay of polymer structure and supramolecular group stoichiometry reveals complicated but rationally describable trends that demonstrate how the supramolecular scaffold design can modulate the strength of multivalent interactions. This approach to self-assembled supramolecular materials thus allows for the manipulation of polymer-nanoparticle composites with controlled thermal stability, nanoparticle organization, and tailored meso- to microscopic structures. The sophisticated control of multivalent thermodynamics through precise modulation of the nanoscale scaffold geometry represents a significant advance in the ability to rationally design complex hierarchically structured materials via self-assembly.

13.
Hippocampus ; 34(5): 241-260, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38415962

RESUMO

The medial temporal lobe (MTL) cortex, located adjacent to the hippocampus, is crucial for memory and prone to the accumulation of certain neuropathologies such as Alzheimer's disease neurofibrillary tau tangles. The MTL cortex is composed of several subregions which differ in their functional and cytoarchitectonic features. As neuroanatomical schools rely on different cytoarchitectonic definitions of these subregions, it is unclear to what extent their delineations of MTL cortex subregions overlap. Here, we provide an overview of cytoarchitectonic definitions of the entorhinal and parahippocampal cortices as well as Brodmann areas (BA) 35 and 36, as provided by four neuroanatomists from different laboratories, aiming to identify the rationale for overlapping and diverging delineations. Nissl-stained series were acquired from the temporal lobes of three human specimens (two right and one left hemisphere). Slices (50 µm thick) were prepared perpendicular to the long axis of the hippocampus spanning the entire longitudinal extent of the MTL cortex. Four neuroanatomists annotated MTL cortex subregions on digitized slices spaced 5 mm apart (pixel size 0.4 µm at 20× magnification). Parcellations, terminology, and border placement were compared among neuroanatomists. Cytoarchitectonic features of each subregion are described in detail. Qualitative analysis of the annotations showed higher agreement in the definitions of the entorhinal cortex and BA35, while the definitions of BA36 and the parahippocampal cortex exhibited less overlap among neuroanatomists. The degree of overlap of cytoarchitectonic definitions was partially reflected in the neuroanatomists' agreement on the respective delineations. Lower agreement in annotations was observed in transitional zones between structures where seminal cytoarchitectonic features are expressed less saliently. The results highlight that definitions and parcellations of the MTL cortex differ among neuroanatomical schools and thereby increase understanding of why these differences may arise. This work sets a crucial foundation to further advance anatomically-informed neuroimaging research on the human MTL cortex.


Assuntos
Lobo Temporal , Humanos , Lobo Temporal/patologia , Neuroanatomia/métodos , Masculino , Giro Para-Hipocampal/patologia , Giro Para-Hipocampal/diagnóstico por imagem , Feminino , Idoso , Córtex Entorrinal/patologia , Córtex Entorrinal/anatomia & histologia , Laboratórios , Idoso de 80 Anos ou mais
14.
Ann Surg ; 279(4): 620-630, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38009646

RESUMO

OBJECTIVE: This systematic review and meta-analysis seeks to evaluate the impact of total neoadjuvant therapy (TNT) for rectal cancers on surgical complications and surgical pathology when compared with standard long-course chemoradiotherapy (LCRT). BACKGROUND: The oncological benefits of TNT are well published in previous meta-analyses, but there is little synthesized information on how it affects surgical outcomes. A recent study has suggested an increase in local recurrence and higher rates of breached total mesorectal excision (TME) plane in TNT patients. METHODS: This study conformed to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A search was performed in Medline (via PubMed), Cochrane databases, EMBASE and CINAHL to identify relevant randomized controlled trials (RCTs) comparing outcomes between TNT and LCRT. Meta-analyses of pooled proportions between TNT and LCRT were performed, comparing primary outcomes of surgical mortality, morbidity and all reported complications; surgical-pathology differences, namely mesorectal quality, R0 resection rates, circumferential resection margin positive rates, and sphincter preservation rates. Death and progression of disease during neoadjuvant treatment period was also compared. Risk of bias of RCTs was performed using the Cochrane risk-of-bias tool by 2 independent reviewers. RESULTS: A total of 3185 patients with rectal cancer from 11 RCTs were included in the analysis: 1607 received TNT and 1578 received LCRT, of which 1422 (TNT arm) and 1391 (LCRT arm) underwent surgical resection with curative intent. There was no significant difference in mortality [risk ratio (RR)=0.86, 95% CI: 0.13-5.52, P =0.88, I2 =52%] or major complications (RR=1.04, 95% CI: 0.86-1.26, P =0.70, I2 =0%) between TNT and LCRT. There was a significantly higher risk of breached TME in TNT group on pooled analysis (RR=1.49, 95% CI: 1.03-12.16, P =0.03, I2 =0%), and on subgroup analysis there is higher risk of breached TME in those receiving extended duration of neoadjuvant treatment (>17 weeks from start of treatment to surgery) when compared with LCRT (RR=1.61, 95% CI: 1.06-2.44, P =0.03). No difference in R0 resection rates (RR=0.85, 95% CI: 0.66-1.10, P =0.21, I2 =15%), circumferential resection margin positive rates (RR=0.87, 95% CI: 0.65-1.16, P =0.35, I2 =10%) or sphincter preservation rates (RR=1.02, 95% CI: 0.83-1.25, P =0.88, I2 =57%) were observed. There was a significantly lower risk of progression of disease to an unresectable stage during the neoadjuvant treatment period in TNT patients (RR=0.60, 95% CI: 0.39-0.92, P =0.03, I2 =18%). On subgroup analysis, it appears to favor those receiving extended duration of neoadjuvant treatment (RR=0.44, 95% CI: 0.26-0.80, P =0.002), and those receiving induction-type chemotherapy in TNT (RR=0.25, 95% CI: 0.07-0.88, P =0.03). CONCLUSIONS: TNT increases rates of breached TME which can contribute to higher local recurrence rates. TNT, however, improves systemic control by reducing early progression of disease during neoadjuvant treatment period. Further research is warranted to identify patients that will benefit from this strategy.


Assuntos
Terapia Neoadjuvante , Neoplasias Retais , Humanos , Margens de Excisão , Ensaios Clínicos Controlados Aleatórios como Assunto , Neoplasias Retais/cirurgia , Neoplasias Retais/patologia , Quimiorradioterapia , Resultado do Tratamento
15.
Lancet ; 402(10411): 1449-1458, 2023 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-37696275

RESUMO

BACKGROUND: Geographic atrophy is an advanced form of dry age-related macular degeneration that can lead to irreversible vision loss and high burden of disease. We aimed to assess efficacy and safety of avacincaptad pegol 2 mg in reducing geographic atrophy lesion growth. METHODS: GATHER2 is a randomised, double-masked, sham-controlled, 24-month, phase 3 trial across 205 retina clinics, research hospitals, and academic institutions globally. To be eligible, patients had to be aged 50 years or older with non-centrepoint-involving geographic atrophy and best corrected visual acuity between 20/25 and 20/320 in the study eye. Eligible patients were randomly assigned (1:1) to monthly avacincaptad pegol 2 mg administered as a 100 µL intravitreal injection or sham for the first 12 months. Randomisation was performed using an interactive response technology system with stratification by factors known to be of prognostic importance in age-related macular degeneration. Patients, investigators, study centre staff, sponsor personnel, and data analysts were masked to treatment allocation. The primary endpoint was geographic atrophy lesion size measured by fundus autofluorescence at baseline, month 6, and month 12. Efficacy and safety analyses were done in the modified intention-to-treat and safety populations, respectively. This trial is registered with ClinicalTrials.gov, NCT04435366. FINDINGS: Between June 22, 2020, and July 23, 2021, 1422 patients were screened for eligibility, of whom 448 were enrolled and randomly assigned to avacincaptad pegol 2 mg (n=225) or sham (n=223). One patient in the sham group did not receive study treatment and was excluded from analyses. There were 154 (68%) female patients and 71 (32%) male patients in the avacincaptad pegol 2 mg group, and 156 (70%) female patients and 66 (30%) male patients in the sham group. From baseline to month 12, the mean rate of square-root-transformed geographic atrophy area growth was 0·336 mm/year (SE 0·032) with avacincaptad pegol 2 mg and 0·392 mm/year (0·033) with sham, a difference in growth of 0·056 mm/year (95% CI 0·016-0·096; p=0·0064), representing a 14% difference between the avacincaptad pegol 2 mg group and the sham group. Ocular treatment-emergent adverse events in the study eye occurred in 110 (49%) patients in the avacincaptad pegol 2 mg group and 83 (37%) in the sham group. There were no endophthalmitis, intraocular inflammation, or ischaemic optic neuropathy events over 12 months. To month 12, macular neovascularisation in the study eye occurred in 15 (7%) patients in the avacincaptad pegol 2 mg group and nine (4%) in the sham group, with exudative macular neovascularisation occurring in 11 (5%) in the avacincaptad pegol 2 mg group and seven (3%) in the sham group. INTERPRETATION: Monthly avacincaptad pegol 2 mg was well tolerated and showed significantly slower geographic atrophy growth over 12 months than sham treatment, suggesting that avacincaptad pegol might slow disease progression and potentially change the trajectory of disease for patients with geographic atrophy. FUNDING: Iveric Bio, An Astellas Company.

16.
N Engl J Med ; 385(19): 1774-1785, 2021 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-34551225

RESUMO

BACKGROUND: At interim analysis in a phase 3, observer-blinded, placebo-controlled clinical trial, the mRNA-1273 vaccine showed 94.1% efficacy in preventing coronavirus disease 2019 (Covid-19). After emergency use of the vaccine was authorized, the protocol was amended to include an open-label phase. Final analyses of efficacy and safety data from the blinded phase of the trial are reported. METHODS: We enrolled volunteers who were at high risk for Covid-19 or its complications; participants were randomly assigned in a 1:1 ratio to receive two intramuscular injections of mRNA-1273 (100 µg) or placebo, 28 days apart, at 99 centers across the United States. The primary end point was prevention of Covid-19 illness with onset at least 14 days after the second injection in participants who had not previously been infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The data cutoff date was March 26, 2021. RESULTS: The trial enrolled 30,415 participants; 15,209 were assigned to receive the mRNA-1273 vaccine, and 15,206 to receive placebo. More than 96% of participants received both injections, 2.3% had evidence of SARS-CoV-2 infection at baseline, and the median follow-up was 5.3 months in the blinded phase. Vaccine efficacy in preventing Covid-19 illness was 93.2% (95% confidence interval [CI], 91.0 to 94.8), with 55 confirmed cases in the mRNA-1273 group (9.6 per 1000 person-years; 95% CI, 7.2 to 12.5) and 744 in the placebo group (136.6 per 1000 person-years; 95% CI, 127.0 to 146.8). The efficacy in preventing severe disease was 98.2% (95% CI, 92.8 to 99.6), with 2 cases in the mRNA-1273 group and 106 in the placebo group, and the efficacy in preventing asymptomatic infection starting 14 days after the second injection was 63.0% (95% CI, 56.6 to 68.5), with 214 cases in the mRNA-1273 group and 498 in the placebo group. Vaccine efficacy was consistent across ethnic and racial groups, age groups, and participants with coexisting conditions. No safety concerns were identified. CONCLUSIONS: The mRNA-1273 vaccine continued to be efficacious in preventing Covid-19 illness and severe disease at more than 5 months, with an acceptable safety profile, and protection against asymptomatic infection was observed. (Funded by the Biomedical Advanced Research and Development Authority and the National Institute of Allergy and Infectious Diseases; COVE ClinicalTrials.gov number, NCT04470427.).


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Imunogenicidade da Vacina , Vacina de mRNA-1273 contra 2019-nCoV , Adolescente , Adulto , Idoso , COVID-19/epidemiologia , Vacinas contra COVID-19/efeitos adversos , Seguimentos , Humanos , Imunização Secundária , Incidência , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Gravidade do Paciente , Método Simples-Cego , Resultado do Tratamento , Adulto Jovem
17.
N Engl J Med ; 384(21): 1981-1990, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-33999548

RESUMO

BACKGROUND: The appropriate dose of aspirin to lower the risk of death, myocardial infarction, and stroke and to minimize major bleeding in patients with established atherosclerotic cardiovascular disease is a subject of controversy. METHODS: Using an open-label, pragmatic design, we randomly assigned patients with established atherosclerotic cardiovascular disease to a strategy of 81 mg or 325 mg of aspirin per day. The primary effectiveness outcome was a composite of death from any cause, hospitalization for myocardial infarction, or hospitalization for stroke, assessed in a time-to-event analysis. The primary safety outcome was hospitalization for major bleeding, also assessed in a time-to-event analysis. RESULTS: A total of 15,076 patients were followed for a median of 26.2 months (interquartile range [IQR], 19.0 to 34.9). Before randomization, 13,537 (96.0% of those with available information on previous aspirin use) were already taking aspirin, and 85.3% of these patients were previously taking 81 mg of daily aspirin. Death, hospitalization for myocardial infarction, or hospitalization for stroke occurred in 590 patients (estimated percentage, 7.28%) in the 81-mg group and 569 patients (estimated percentage, 7.51%) in the 325-mg group (hazard ratio, 1.02; 95% confidence interval [CI], 0.91 to 1.14). Hospitalization for major bleeding occurred in 53 patients (estimated percentage, 0.63%) in the 81-mg group and 44 patients (estimated percentage, 0.60%) in the 325-mg group (hazard ratio, 1.18; 95% CI, 0.79 to 1.77). Patients assigned to 325 mg had a higher incidence of dose switching than those assigned to 81 mg (41.6% vs. 7.1%) and fewer median days of exposure to the assigned dose (434 days [IQR, 139 to 737] vs. 650 days [IQR, 415 to 922]). CONCLUSIONS: In this pragmatic trial involving patients with established cardiovascular disease, there was substantial dose switching to 81 mg of daily aspirin and no significant differences in cardiovascular events or major bleeding between patients assigned to 81 mg and those assigned to 325 mg of aspirin daily. (Funded by the Patient-Centered Outcomes Research Institute; ADAPTABLE ClinicalTrials.gov number, NCT02697916.).


Assuntos
Aspirina/administração & dosagem , Doenças Cardiovasculares/tratamento farmacológico , Inibidores da Agregação Plaquetária/administração & dosagem , Idoso , Aspirina/efeitos adversos , Aterosclerose/tratamento farmacológico , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/prevenção & controle , Feminino , Hemorragia/induzido quimicamente , Hospitalização , Humanos , Masculino , Adesão à Medicação/estatística & dados numéricos , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/prevenção & controle , Inibidores da Agregação Plaquetária/efeitos adversos , Prevenção Secundária , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controle
18.
Int J Obes (Lond) ; 48(2): 224-230, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37898714

RESUMO

BACKGROUND: Atrial fibrillation (AF) is an indicator of poor prognosis in patients with sepsis and can increase the risk of stroke and mortality. Data on the impact of severe obesity on the outcomes of sepsis complicated by AF remains poorly understood. METHODS: National Inpatient Sample (2018) and ICD-10 CM codes were used to identify the principal sepsis admissions with AF. We assessed comorbidities and outcomes of sepsis in people without obesity (BMI < 30) vs. non-severe obesity (BMI 30-35) and severe obesity (BMI > 35) cohorts. We also did a subgroup analysis to further stratify obesity based on metabolic health and analyzed the findings. The primary outcomes were the prevalence and adjusted odds of AF, AF-associated stroke, and all-cause mortality in sepsis by obesity status. Multivariable regression analyses were adjusted for patient- and hospital-level characteristics and comorbidities. RESULTS: Our main analysis showed that of the 1,345,595 sepsis admissions, the severe obesity cohort was the youngest (median age 59 vs. non-severe 64 and people without obesity 68 years). Patients with obesity, who were often female, were more likely to have hypertension, diabetes, congestive heart failure, chronic pulmonary disease, and chronic kidney disease. The crude prevalence of AF was highest in non-severe obesity (19.9%). The adjusted odds of AF in non-severe obesity (OR 1.21; 95% CI:1.16-1.27) and severe obesity patients with sepsis (OR 1.49; 95% CI:1.43-1.55) were significantly higher than in people without obesity (p < 0.001). Paradoxically, the rates of AF-associated stroke (1%, 1.5%, and 1.7%) and in-hospital mortality (3.3%, 4.9%, and 7.1%) were lowest in the severe obesity cohort vs. the non-severe and people without obesity cohorts, respectively. On multivariable regression analyses, the all-cause mortality revealed lower odds in sepsis-AF patients with severe obesity (OR 0.78; 95% CI:0.67-0.91) or non-severe obesity (OR 0.63; 95% CI:0.54-0.74) vs. people without obesity. There was no significant difference in stroke risk. CONCLUSIONS: A higher prevalence of cardiovascular comorbidities can be linked to a higher risk of AF in people with obesity and sepsis. Paradoxically, lower rates of stroke and all-cause mortality secondary to AF in people with obesity and sepsis warrant further investigation.


Assuntos
Fibrilação Atrial , Obesidade Mórbida , Sepse , Acidente Vascular Cerebral , Humanos , Feminino , Estados Unidos/epidemiologia , Pessoa de Meia-Idade , Fibrilação Atrial/epidemiologia , Obesidade Mórbida/complicações , Obesidade Mórbida/epidemiologia , Fatores de Risco , Obesidade/complicações , Obesidade/epidemiologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/epidemiologia , Sepse/complicações , Sepse/epidemiologia
19.
J Transl Med ; 22(1): 627, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38965566

RESUMO

BACKGROUND: Post-exertional malaise (PEM), the hallmark symptom of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), represents a constellation of abnormal responses to physical, cognitive, and/or emotional exertion including profound fatigue, cognitive dysfunction, and exertion intolerance, among numerous other maladies. Two sequential cardiopulmonary exercise tests (2-d CPET) provide objective evidence of abnormal responses to exertion in ME/CFS but validated only in studies with small sample sizes. Further, translation of results to impairment status and approaches to symptom reduction are lacking. METHODS: Participants with ME/CFS (Canadian Criteria; n = 84) and sedentary controls (CTL; n = 71) completed two CPETs on a cycle ergometer separated by 24 h. Two-way repeated measures ANOVA compared CPET measures at rest, ventilatory/anaerobic threshold (VAT), and peak effort between phenotypes and CPETs. Intraclass correlations described stability of CPET measures across tests, and relevant objective CPET data indicated impairment status. A subset of case-control pairs (n = 55) matched for aerobic capacity, age, and sex, were also analyzed. RESULTS: Unlike CTL, ME/CFS failed to reproduce CPET-1 measures during CPET-2 with significant declines at peak exertion in work, exercise time, V ˙ e, V ˙ O2, V ˙ CO2, V ˙ T, HR, O2pulse, DBP, and RPP. Likewise, CPET-2 declines were observed at VAT for V ˙ e/ V ˙ CO2, PetCO2, O2pulse, work, V ˙ O2 and SBP. Perception of effort (RPE) exceeded maximum effort criteria for ME/CFS and CTL on both CPETs. Results were similar in matched pairs. Intraclass correlations revealed greater stability in CPET variables across test days in CTL compared to ME/CFS owing to CPET-2 declines in ME/CFS. Lastly, CPET-2 data signaled more severe impairment status for ME/CFS compared to CPET-1. CONCLUSIONS: Presently, this is the largest 2-d CPET study of ME/CFS to substantiate impaired recovery in ME/CFS following an exertional stressor. Abnormal post-exertional CPET responses persisted compared to CTL matched for aerobic capacity, indicating that fitness level does not predispose to exertion intolerance in ME/CFS. Moreover, contributions to exertion intolerance in ME/CFS by disrupted cardiac, pulmonary, and metabolic factors implicates autonomic nervous system dysregulation of blood flow and oxygen delivery for energy metabolism. The observable declines in post-exertional energy metabolism translate notably to a worsening of impairment status. Treatment considerations to address tangible reductions in physiological function are proffered. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, retrospectively registered, ID# NCT04026425, date of registration: 2019-07-17.


Assuntos
Teste de Esforço , Síndrome de Fadiga Crônica , Consumo de Oxigênio , Humanos , Síndrome de Fadiga Crônica/fisiopatologia , Síndrome de Fadiga Crônica/terapia , Feminino , Masculino , Adulto , Estudos de Casos e Controles , Pessoa de Meia-Idade , Limiar Anaeróbio
20.
Appl Environ Microbiol ; 90(4): e0204423, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38483171

RESUMO

The ability of some white rot basidiomycetes to remove lignin selectively from wood indicates that low molecular weight oxidants have a role in ligninolysis. These oxidants are likely free radicals generated by fungal peroxidases from compounds in the biodegrading wood. Past work supports a role for manganese peroxidases (MnPs) in the production of ligninolytic oxidants from fungal membrane lipids. However, the fatty acid alkylperoxyl radicals initially formed during this process are not reactive enough to attack the major structures in lignin. Here, we evaluate the hypothesis that the peroxidation of fatty aldehydes might provide a source of more reactive acylperoxyl radicals. We found that Gelatoporia subvermispora produced trans-2-nonenal, trans-2-octenal, and n-hexanal (a likely metabolite of trans-2,4-decadienal) during the incipient decay of aspen wood. Fungal fatty aldehydes supported the in vitro oxidation by MnPs of a nonphenolic lignin model dimer, and also of the monomeric model veratryl alcohol. Experiments with the latter compound showed that the reactions were partially inhibited by oxalate, the chelator that white rot fungi employ to detach Mn3+ from the MnP active site, but nevertheless proceeded at its physiological concentration of 1 mM. The addition of catalase was inhibitory, which suggests that the standard MnP catalytic cycle is involved in the oxidation of aldehydes. MnP oxidized trans-2-nonenal quantitatively to trans-2-nonenoic acid with the consumption of one O2 equivalent. The data suggest that when Mn3+ remains associated with MnP, it can oxidize aldehydes to their acyl radicals, and the latter subsequently add O2 to become ligninolytic acylperoxyl radicals.IMPORTANCEThe biodegradation of lignin by white rot fungi is essential for the natural recycling of plant biomass and has useful applications in lignocellulose bioprocessing. Although fungal peroxidases have a key role in ligninolysis, past work indicates that biodegradation is initiated by smaller, as yet unidentified oxidants that can infiltrate the substrate. Here, we present evidence that the peroxidase-catalyzed oxidation of naturally occurring fungal aldehydes may provide a source of ligninolytic free radical oxidants.


Assuntos
Basidiomycota , Manganês , Polyporales , Lignina/metabolismo , Proteínas Fúngicas/metabolismo , Basidiomycota/metabolismo , Aldeídos , Peroxidases/metabolismo , Ácidos Graxos , Oxidantes
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