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1.
Cell ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38942013

RESUMEN

The ability of proteins and RNA to coalesce into phase-separated assemblies, such as the nucleolus and stress granules, is a basic principle in organizing membraneless cellular compartments. While the constituents of biomolecular condensates are generally well documented, the mechanisms underlying their formation under stress are only partially understood. Here, we show in yeast that covalent modification with the ubiquitin-like modifier Urm1 promotes the phase separation of a wide range of proteins. We find that the drop in cellular pH induced by stress triggers Urm1 self-association and its interaction with both target proteins and the Urm1-conjugating enzyme Uba4. Urmylation of stress-sensitive proteins promotes their deposition into stress granules and nuclear condensates. Yeast cells lacking Urm1 exhibit condensate defects that manifest in reduced stress resilience. We propose that Urm1 acts as a reversible molecular "adhesive" to drive protective phase separation of functionally critical proteins under cellular stress.

2.
Cell ; 186(15): 3227-3244.e20, 2023 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-37339632

RESUMEN

Readthrough into the 3' untranslated region (3' UTR) of the mRNA results in the production of aberrant proteins. Metazoans efficiently clear readthrough proteins, but the underlying mechanisms remain unknown. Here, we show in Caenorhabditis elegans and mammalian cells that readthrough proteins are targeted by a coupled, two-level quality control pathway involving the BAG6 chaperone complex and the ribosome-collision-sensing protein GCN1. Readthrough proteins with hydrophobic C-terminal extensions (CTEs) are recognized by SGTA-BAG6 and ubiquitylated by RNF126 for proteasomal degradation. Additionally, cotranslational mRNA decay initiated by GCN1 and CCR4/NOT limits the accumulation of readthrough products. Unexpectedly, selective ribosome profiling uncovered a general role of GCN1 in regulating translation dynamics when ribosomes collide at nonoptimal codons, enriched in 3' UTRs, transmembrane proteins, and collagens. GCN1 dysfunction increasingly perturbs these protein classes during aging, resulting in mRNA and proteome imbalance. Our results define GCN1 as a key factor acting during translation in maintaining protein homeostasis.


Asunto(s)
Biosíntesis de Proteínas , Ribosomas , Animales , Ribosomas/metabolismo , Proteínas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Codón de Terminación/metabolismo , Mamíferos/metabolismo
3.
Cell ; 185(22): 4117-4134.e28, 2022 10 27.
Artículo en Inglés | MEDLINE | ID: mdl-36306734

RESUMEN

In most sensory modalities, neuronal connectivity reflects behaviorally relevant stimulus features, such as spatial location, orientation, and sound frequency. By contrast, the prevailing view in the olfactory cortex, based on the reconstruction of dozens of neurons, is that connectivity is random. Here, we used high-throughput sequencing-based neuroanatomical techniques to analyze the projections of 5,309 mouse olfactory bulb and 30,433 piriform cortex output neurons at single-cell resolution. Surprisingly, statistical analysis of this much larger dataset revealed that the olfactory cortex connectivity is spatially structured. Single olfactory bulb neurons targeting a particular location along the anterior-posterior axis of piriform cortex also project to matched, functionally distinct, extra-piriform targets. Moreover, single neurons from the targeted piriform locus also project to the same matched extra-piriform targets, forming triadic circuit motifs. Thus, as in other sensory modalities, olfactory information is routed at early stages of processing to functionally diverse targets in a coordinated manner.


Asunto(s)
Corteza Olfatoria , Vías Olfatorias , Ratones , Animales , Bulbo Olfatorio , Neuronas/fisiología , Secuenciación de Nucleótidos de Alto Rendimiento
4.
Am J Hum Genet ; 110(1): 105-119, 2023 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-36493768

RESUMEN

Adult-onset cerebellar ataxias are a group of neurodegenerative conditions that challenge both genetic discovery and molecular diagnosis. In this study, we identified an intronic (GAA) repeat expansion in fibroblast growth factor 14 (FGF14). Genetic analysis of 95 Australian individuals with adult-onset ataxia identified four (4.2%) with (GAA)>300 and a further nine individuals with (GAA)>250. PCR and long-read sequence analysis revealed these were pure (GAA) repeats. In comparison, no control subjects had (GAA)>300 and only 2/311 control individuals (0.6%) had a pure (GAA)>250. In a German validation cohort, 9/104 (8.7%) of affected individuals had (GAA)>335 and a further six had (GAA)>250, whereas 10/190 (5.3%) control subjects had (GAA)>250 but none were (GAA)>335. The combined data suggest (GAA)>335 are disease causing and fully penetrant (p = 6.0 × 10-8, OR = 72 [95% CI = 4.3-1,227]), while (GAA)>250 is likely pathogenic with reduced penetrance. Affected individuals had an adult-onset, slowly progressive cerebellar ataxia with variable features including vestibular impairment, hyper-reflexia, and autonomic dysfunction. A negative correlation between age at onset and repeat length was observed (R2 = 0.44, p = 0.00045, slope = -0.12) and identification of a shared haplotype in a minority of individuals suggests that the expansion can be inherited or generated de novo during meiotic division. This study demonstrates the power of genome sequencing and advanced bioinformatic tools to identify novel repeat expansions via model-free, genome-wide analysis and identifies SCA50/ATX-FGF14 as a frequent cause of adult-onset ataxia.


Asunto(s)
Ataxia Cerebelosa , Factores de Crecimiento de Fibroblastos , Ataxia de Friedreich , Expansión de Repetición de Trinucleótido , Adulto , Humanos , Ataxia/genética , Australia , Ataxia Cerebelosa/genética , Ataxia de Friedreich/genética , Expansión de Repetición de Trinucleótido/genética
5.
N Engl J Med ; 389(21): 1949-1960, 2023 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-37874020

RESUMEN

BACKGROUND: A previous analysis in this trial showed that among patients with severe, symptomatic aortic stenosis who were at low surgical risk, the rate of the composite end point of death, stroke, or rehospitalization at 1 year was significantly lower with transcatheter aortic-valve replacement (TAVR) than with surgical aortic-valve replacement. Longer-term outcomes are unknown. METHODS: We randomly assigned patients with severe, symptomatic aortic stenosis and low surgical risk to undergo either TAVR or surgery. The first primary end point was a composite of death, stroke, or rehospitalization related to the valve, the procedure, or heart failure. The second primary end point was a hierarchical composite that included death, disabling stroke, nondisabling stroke, and the number of rehospitalization days, analyzed with the use of a win ratio analysis. Clinical, echocardiographic, and health-status outcomes were assessed through 5 years. RESULTS: A total of 1000 patients underwent randomization: 503 patients were assigned to undergo TAVR, and 497 to undergo surgery. A component of the first primary end point occurred in 111 of 496 patients in the TAVR group and in 117 of 454 patients in the surgery group (Kaplan-Meier estimates, 22.8% in the TAVR group and 27.2% in the surgery group; difference, -4.3 percentage points; 95% confidence interval [CI], -9.9 to 1.3; P = 0.07). The win ratio for the second primary end point was 1.17 (95% CI, 0.90 to 1.51; P = 0.25). The Kaplan-Meier estimates for the components of the first primary end point were as follows: death, 10.0% in the TAVR group and 8.2% in the surgery group; stroke, 5.8% and 6.4%, respectively; and rehospitalization, 13.7% and 17.4%. The hemodynamic performance of the valve, assessed according to the mean (±SD) valve gradient, was 12.8±6.5 mm Hg in the TAVR group and 11.7±5.6 mm Hg in the surgery group. Bioprosthetic-valve failure occurred in 3.3% of the patients in the TAVR group and in 3.8% of those in the surgery group. CONCLUSIONS: Among low-risk patients with severe, symptomatic aortic stenosis who underwent TAVR or surgery, there was no significant between-group difference in the two primary composite outcomes. (Funded by Edwards Lifesciences; PARTNER 3 ClinicalTrials.gov number, NCT02675114.).


Asunto(s)
Estenosis de la Válvula Aórtica , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/mortalidad , Estenosis de la Válvula Aórtica/cirugía , Prótesis Valvulares Cardíacas , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/métodos , Complicaciones Posoperatorias/etiología , Factores de Riesgo , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/cirugía , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Reemplazo de la Válvula Aórtica Transcatéter/mortalidad , Resultado del Tratamiento , Estudios de Seguimiento , Readmisión del Paciente , Insuficiencia Cardíaca/etiología
6.
Proc Natl Acad Sci U S A ; 120(24): e2302580120, 2023 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-37276423

RESUMEN

AmiA and AmiB are peptidoglycan-hydrolyzing enzymes from Escherichia coli that are required to break the peptidoglycan layer during bacterial cell division and maintain integrity of the cell envelope. In vivo, the activity of AmiA and AmiB is tightly controlled through their interactions with the membrane-bound FtsEX-EnvC complex. Activation of AmiA and AmiB requires access to a groove in the amidase-activating LytM domain of EnvC which is gated by ATP-driven conformational changes in FtsEX-EnvC complex. Here, we present a high-resolution structure of the isolated AmiA protein, confirming that it is autoinhibited in the same manner as AmiB and AmiC, and a complex of the AmiB enzymatic domain bound to the activating EnvC LytM domain. In isolation, the active site of AmiA is blocked by an autoinhibitory helix that binds directly to the catalytic zinc and fills the volume expected to accommodate peptidoglycan binding. In the complex, binding of the EnvC LytM domain induces a conformational change that displaces the amidase autoinhibitory helix and reorganizes the active site for activity. Our structures, together with complementary mutagenesis work, defines the conformational changes required to activate AmiA and/or AmiB through their interaction with their cognate activator EnvC.


Asunto(s)
Proteínas de Escherichia coli , Proteínas de Escherichia coli/metabolismo , Peptidoglicano/metabolismo , N-Acetil Muramoil-L-Alanina Amidasa/metabolismo , Escherichia coli/metabolismo , Amidohidrolasas/metabolismo , Proteínas Bacterianas/metabolismo
7.
Circulation ; 149(10): 734-743, 2024 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-37874908

RESUMEN

BACKGROUND: Atrial fibrillation (AF) is common in patients undergoing transcatheter aortic valve replacement (TAVR) and is associated with increased risk of bleeding and stroke. While left atrial appendage occlusion (LAAO) is approved as an alternative to anticoagulants for stroke prevention in patients with AF, placement of these devices in patients with severe aortic stenosis, or when performed at the same time as TAVR, has not been extensively studied. METHODS: WATCH-TAVR (WATCHMAN for Patients with AF Undergoing TAVR) was a multicenter, randomized trial evaluating the safety and effectiveness of concomitant TAVR and LAAO with WATCHMAN in AF patients. Patients were randomized 1:1 to TAVR + LAAO or TAVR + medical therapy. WATCHMAN patients received anticoagulation for 45 days followed by dual antiplatelet therapy until 6 months. Anticoagulation was per treating physician preference for patients randomized to TAVR + medical therapy. The primary noninferiority end point was all-cause mortality, stroke, and major bleeding at 2 years between the 2 strategies. RESULTS: The study enrolled 349 patients (177 TAVR + LAAO and 172 TAVR + medical therapy) between December 2017 and November 2020 at 34 US centers. The mean age of patients was 81 years, and the mean scores for CHA2DS2-VASc and HAS-BLED (Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile INR, Elderly, Drugs/alcohol concomitantly) were 4.9 and 3.0, respectively. At baseline, 85.4% of patients were taking anticoagulants and 71.3% patients were on antiplatelet therapy. The cohorts were well-balanced for baseline characteristics. The incremental LAAO procedure time was 38 minutes, and the median contrast volume used for combined procedures was 119 mL versus 70 mL with TAVR alone. At the 24-month follow-up, 82.5% compared with 50.8% of patients were on any antiplatelet therapy, and 13.9% compared with 66.7% of patients were on any anticoagulation therapy in TAVR + LAAO compared with TAVR + medical therapy group, respectively. For the composite primary end point, TAVR + LAAO was noninferior to TAVR + medical therapy (22.7 versus 27.3 events per 100 patient-years for TAVR + LAAO and TAVR + medical therapy, respectively; hazard ratio, 0.86 [95% CI, 0.60-1.22]; Pnoninferiority<0.001). CONCLUSIONS: Concomitant WATCHMAN LAAO and TAVR is noninferior to TAVR with medical therapy in severe aortic stenosis patients with AF. The increased complexity and risks of the combined procedure should be considered when concomitant LAAO is viewed as an alternative to medical therapy for patients with AF undergoing TAVR. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03173534.


Asunto(s)
Estenosis de la Válvula Aórtica , Apéndice Atrial , Fibrilación Atrial , Accidente Cerebrovascular , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/complicaciones , Fibrilación Atrial/tratamiento farmacológico , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Inhibidores de Agregación Plaquetaria/efectos adversos , Apéndice Atrial/cirugía , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/prevención & control , Hemorragia/inducido químicamente , Anticoagulantes/efectos adversos , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/cirugía , Resultado del Tratamiento
8.
Lancet ; 403(10435): 1451-1459, 2024 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-38552656

RESUMEN

BACKGROUND: Surgery remains the only recommended intervention for patients with native aortic regurgitation. A transcatheter therapy to treat patients at high risk for mortality and complications with surgical aortic valve replacement represents an unmet need. Commercial transcatheter heart valves in pure aortic regurgitation are hampered by unacceptable rates of embolisation and paravalvular regurgitation. The Trilogy transcatheter heart valve (JenaValve Technology, Irvine, CA, USA) provides a treatment option for these patients. We report outcomes with transfemoral transcatheter aortic valve implantation (TAVI) in patients with pure aortic regurgitation using this dedicated transcatheter heart valve. METHODS: The ALIGN-AR trial is a prospective, multicentre, single-arm study. We recruited symptomatic patients (aged ≥18 years) with moderate-to-severe or severe aortic regurgitation at high risk for mortality and complications after surgical aortic valve replacement at 20 US sites for treatment with the Trilogy transcatheter heart valve. The 30-day composite primary safety endpoint was compared for non-inferiority with a prespecified performance goal of 40·5%. The primary efficacy endpoint was 1-year all-cause mortality compared for non-inferiority with a performance goal of 25%. This trial is registered with ClinicalTrials.gov, NCT04415047, and is ongoing. FINDINGS: Between June 8, 2018, and Aug 29, 2022, we screened 346 patients. We excluded 166 (48%) patients and enrolled 180 (52%) patients with symptomatic aortic regurgitation deemed high risk by the heart team and independent screening committee assessments. The mean age of the study population was 75·5 years (SD 10·8), and 85 (47%) were female, 95 (53%) were male, and 131 (73%) were White. Technical success was achieved in 171 (95%) patients. At 30 days, four (2%) deaths, two (1%) disabling strokes, and two (1%) non-disabling strokes occurred. Using standard Valve Academic Research Consortium-2 definitions, the primary safety endpoint was achieved, with events occurring in 48 (27% [97·5% CI 19·2-34·0]) patients (pnon-inferiority<0·0001), with new pacemaker implantation in 36 (24%) patients. The primary efficacy endpoint was achieved, with mortality in 14 (7·8% [3·3-12·3]) patients at 1 year (pnon-inferiority<0·0001). INTERPRETATION: This study shows the safety and effectiveness of treating native aortic regurgitation using a dedicated transcatheter heart valve to treat patients with symptomatic moderate-to-severe or severe aortic regurgitation who are at high risk for mortality or complications after surgical aortic valve replacement. The observed short-term clinical and haemodynamic outcomes are promising as are signs of left ventricular remodelling, but long-term follow-up is necessary. FUNDING: JenaValve Technology.


Asunto(s)
Insuficiencia de la Válvula Aórtica , Estenosis de la Válvula Aórtica , Prótesis Valvulares Cardíacas , Reemplazo de la Válvula Aórtica Transcatéter , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Insuficiencia de la Válvula Aórtica/etiología , Insuficiencia de la Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/cirugía , Estudios Prospectivos , Diseño de Prótesis , Factores de Riesgo , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Resultado del Tratamiento
9.
Proc Natl Acad Sci U S A ; 119(8)2022 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-35131896

RESUMEN

Orkney was a major cultural center during the Neolithic, 3800 to 2500 BC. Farming flourished, permanent stone settlements and chambered tombs were constructed, and long-range contacts were sustained. From ∼3200 BC, the number, density, and extravagance of settlements increased, and new ceremonial monuments and ceramic styles, possibly originating in Orkney, spread across Britain and Ireland. By ∼2800 BC, this phenomenon was waning, although Neolithic traditions persisted to at least 2500 BC. Unlike elsewhere in Britain, there is little material evidence to suggest a Beaker presence, suggesting that Orkney may have developed along an insular trajectory during the second millennium BC. We tested this by comparing new genomic evidence from 22 Bronze Age and 3 Iron Age burials in northwest Orkney with Neolithic burials from across the archipelago. We identified signals of inward migration on a scale unsuspected from the archaeological record: As elsewhere in Bronze Age Britain, much of the population displayed significant genome-wide ancestry deriving ultimately from the Pontic-Caspian Steppe. However, uniquely in northern and central Europe, most of the male lineages were inherited from the local Neolithic. This suggests that some male descendants of Neolithic Orkney may have remained distinct well into the Bronze Age, although there are signs that this had dwindled by the Iron Age. Furthermore, although the majority of mitochondrial DNA lineages evidently arrived afresh with the Bronze Age, we also find evidence for continuity in the female line of descent from Mesolithic Britain into the Bronze Age and even to the present day.


Asunto(s)
ADN Mitocondrial/genética , Migración Humana/historia , Herencia Paterna/genética , Arqueología , ADN Antiguo/análisis , Inglaterra , Europa (Continente) , Femenino , Fósiles , Pool de Genes , Genoma Humano/genética , Genómica , Haplotipos , Historia Antigua , Historia Medieval , Humanos , Irlanda , Masculino , Escocia
10.
Eur Heart J ; 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38747561

RESUMEN

BACKGROUND AND AIMS: This trial sought to assess the safety and efficacy of ShortCut, the first dedicated leaflet modification device, prior to transcatheter aortic valve implantation (TAVI) in patients at risk for coronary artery obstruction. METHODS: This pivotal prospective study enrolled patients with failed bioprosthetic aortic valves scheduled to undergo TAVI and were at risk for coronary artery obstruction. The primary safety endpoint was procedure-related mortality or stroke at discharge or 7 days, and the primary efficacy endpoint was per-patient leaflet splitting success. Independent angiographic, echocardiographic, and computed tomography core laboratories assessed all images. Safety events were adjudicated by a clinical events committee and data safety monitoring board. RESULTS: Sixty eligible patients were treated (77.0 ± 9.6 years, 70% female, 96.7% failed surgical bioprosthetic valves, 63.3% single splitting and 36.7% dual splitting) at 22 clinical sites. Successful leaflet splitting was achieved in all (100%; 95% confidence interval [CI] 94-100.0%, p<0.001) patients. Procedure time, including imaging confirmation of leaflet splitting, was 30.6 ± 17.9 min. Freedom from the primary safety endpoint was achieved in 59 (98.3%; 95% CI [91.1-100%]) patients, with no mortality and one (1.7%) disabling stroke. At 30 days, freedom from coronary obstruction was 95% (95% CI 86.1-99.0%). Within 90 days, freedom from mortality was 95% (95% CI 86.1-99.0%]), without any cardiovascular deaths. CONCLUSIONS: Modification of failed bioprosthetic aortic valve leaflets using ShortCut was safe, achieved successful leaflet splitting in all patients, and was associated with favorable clinical outcomes in patients at risk for coronary obstruction undergoing TAVI.

11.
Nano Lett ; 24(6): 2011-2017, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38306708

RESUMEN

Polymeric nanoparticles are a highly promising drug delivery formulation. However, a lack of understanding of the molecular mechanisms that underlie their drug solubilization and controlled release capabilities has hindered the efficient clinical translation of such technologies. Polyethylene glycol-poly(lactic-co-glycolic) acid (PEG-PLGA) nanoparticles have been widely studied as cancer drug delivery vehicles. In this letter, we use unbiased coarse-grained molecular dynamics simulations to model the self-assembly of a PEG-PLGA nanoparticle and its solubulization of the anticancer peptide, EEK, with good agreement with previously reported experimental structural data. We applied unsupervised machine learning techniques to quantify the conformations that polymers adopt at various locations within the nanoparticle. We find that the local microenvironments formed by the various polymer conformations promote preferential EEK solubilization within specific regions of the NP. This demonstrates that these microenvironments are key in controlling drug storage locations within nanoparticles, supporting the rational design of nanoparticles for therapeutic applications.


Asunto(s)
Nanopartículas , Poliésteres , Polímeros , Polímeros/química , Ácido Láctico/química , Polietilenglicoles/química , Sistemas de Liberación de Medicamentos/métodos , Péptidos , Nanopartículas/química , Portadores de Fármacos/química
12.
Circulation ; 147(21): 1594-1605, 2023 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-37154049

RESUMEN

BACKGROUND: In patients with severe symptomatic aortic stenosis at low surgical risk, transfemoral transcatheter aortic valve replacement (TAVR) with the SAPIEN 3 valve has been shown to reduce the composite of death, stroke, or rehospitalization at 2-year follow-up compared with surgical aortic valve replacement (SAVR). Whether TAVR is cost-effective compared with SAVR for low-risk patients remains uncertain. METHODS: Between 2016 and 2017, 1000 low-risk patients with aortic stenosis were randomly assigned to TAVR with the SAPIEN 3 valve or SAVR in the PARTNER 3 trial (Placement of Aortic Transcatheter Valves). Of these patients, 929 underwent valve replacement, were enrolled in the United States, and were included in the economic substudy. Procedural costs were estimated using measured resource use. Other costs were determined by linkage with Medicare claims or by regression models when linkage was not feasible. Health utilities were estimated using the EuroQOL 5-item questionnaire. With the use of a Markov model informed by in-trial data, lifetime cost-effectiveness from the perspective of the US health care system was estimated in terms of cost per quality-adjusted life-year gained. RESULTS: Although procedural costs were nearly $19 000 higher with TAVR, total index hospitalization costs were only $591 more with TAVR compared with SAVR. Follow-up costs were lower with TAVR such that TAVR led to 2-year cost savings of $2030/patient compared with SAVR (95% CI, -$6222 to $1816) and a gain of 0.05 quality-adjusted life-years (95% CI, -0.003 to 0.102). In our base-case analysis, TAVR was projected to be an economically dominant strategy with a 95% probability that the incremental cost-effectiveness ratio for TAVR would be <$50 000/quality-adjusted life-year gained (consistent with high economic value from a US health care perspective). These findings were sensitive to differences in long-term survival, however, such that a modest long-term survival advantage with SAVR would render SAVR cost-effective (although not cost saving) compared with TAVR. CONCLUSIONS: For patients with severe aortic stenosis and low surgical risk similar to those enrolled in the PARTNER 3 trial, transfemoral TAVR with the SAPIEN 3 valve is cost saving compared with SAVR at 2 years and is projected to be economically attractive in the long run as long as there are no substantial differences in late death between the 2 strategies. Long-term follow-up will be critical to ultimately determine the preferred treatment strategy for low-risk patients from both a clinical and economic perspective.


Asunto(s)
Estenosis de la Válvula Aórtica , Implantación de Prótesis de Válvulas Cardíacas , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Anciano , Estados Unidos , Válvula Aórtica/cirugía , Implantación de Prótesis de Válvulas Cardíacas/métodos , Resultado del Tratamiento , Medicare , Reemplazo de la Válvula Aórtica Transcatéter/métodos , Factores de Riesgo
13.
J Am Chem Soc ; 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38842580

RESUMEN

Nonribosomal cyclic peptides (NRcPs) are structurally complex natural products and a vital pool of therapeutics, particularly antibiotics. Their structural diversity arises from the ability of the multidomain enzyme assembly lines, nonribosomal peptide synthetases (NRPSs), to utilize bespoke nonproteinogenic amino acids, modify the linear peptide during elongation, and catalyze an array of cyclization modes, e.g., head to tail, side chain to tail. The study and drug development of NRcPs are often limited by a lack of easy synthetic access to NRcPs and their analogues, with selective macrolactamization being a major bottleneck. Herein, we report a generally applicable chemical macrocyclization method of unprecedented speed and selectivity. Inspired by biosynthetic cyclization, it combines the deprotected linear biosynthetic precursor peptide sequence with a highly reactive C-terminus to produce NRcPs and analogues in minutes. The method was applied to several NRcPs of varying sequences, ring sizes, and cyclization modes including rufomycin, colistin, and gramicidin S with comparable success. We thus demonstrate that the linear order of modules in NRPS enzymes that determines peptide sequence encodes the key structural information to produce peptides conformationally biased toward macrocyclization. To fully exploit this conformational bias synthetically, a highly reactive C-terminal acyl azide is also required, alongside carefully balanced pH and solvent conditions. This allows for consistent, facile cyclization of exceptional speed, selectivity, and atom efficiency. This exciting macrolactamization method represents a new enabling technology for the biosynthetic study of NRcPs and their development as therapeutics.

14.
J Am Chem Soc ; 146(11): 7222-7232, 2024 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-38469853

RESUMEN

Defect centers in a nanodiamond (ND) allow the detection of tiny magnetic fields in their direct surroundings, rendering them as an emerging tool for nanoscale sensing applications. Eumelanin, an abundant pigment, plays an important role in biology and material science. Here, for the first time, we evaluate the comproportionation reaction in eumelanin by detecting and quantifying semiquinone radicals through the nitrogen-vacancy color center. A thin layer of eumelanin is polymerized on the surface of nanodiamonds (NDs), and depending on the environmental conditions, such as the local pH value, near-infrared, and ultraviolet light irradiation, the radicals form and react in situ. By combining experiments and theoretical simulations, we quantify the local number and kinetics of free radicals in the eumelanin layer. Next, the ND sensor enters the cells via endosomal vesicles. We quantify the number of radicals formed within the eumelanin layer in these acidic compartments by applying optical relaxometry measurements. In the future, we believe that the ND quantum sensor could provide valuable insights into the chemistry of eumelanin, which could contribute to the understanding and treatment of eumelanin- and melanin-related diseases.


Asunto(s)
Melaninas , Nanodiamantes , Rayos Ultravioleta , Radicales Libres
15.
Lancet ; 402(10412): 1529-1540, 2023 10 28.
Artículo en Inglés | MEDLINE | ID: mdl-37660719

RESUMEN

BACKGROUND: With increasing numbers of patients undergoing transcatheter aortic valve replacement (TAVR), data on management of failed TAVR, including repeat TAVR procedure, are needed. The aim of this study was to assess the safety and efficacy of redo-TAVR in a national registry. METHODS: This study included all consecutive patients in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry from Nov 9, 2011, to Dec 30, 2022 who underwent TAVR with balloon-expandable valves in failed transcatheter heart valves (redo-TAVR) or native aortic valves (native-TAVR). Procedural, echocardiographic, and clinical outcomes were compared between redo-TAVR and native-TAVR cohorts using propensity score matching. FINDINGS: Among 350 591 patients (1320 redo-TAVR; 349 271 native-TAVR), 1320 propensity-matched pairs of patients undergoing redo-TAVR and native-TAVR were analysed (redo-TAVR cohort: mean age 78 years [SD 9]; 559 [42·3%] of 1320 female, 761 [57·7%] male; mean predicted surgical risk of 30-day mortality 8·1%). The rates of procedural complications of redo-TAVR were low (coronary compression or obstruction: four [0·3%] of 1320; intraprocedural death: eight [0·6%] of 1320; conversion to open heart surgery: six [0·5%] of 1319) and similar to native-TAVR. There was no significant difference between redo-TAVR and native-TAVR populations in death at 30 days (4·7% vs 4·0%, p=0·36) or 1 year (17·5% vs 19·0%, p=0·57), and stroke at 30 days (2·0% vs 1·9%, p=0·84) or 1 year (3·2% vs 3·5%, p=0·80). Redo-TAVR reduced aortic valve gradients at 1 year, although they were higher in the redo-TAVR group compared with the native-TAVR group (15 mm Hg vs 12 mm Hg; p<0·0001). Moderate or severe aortic regurgitation rates were similar between redo-TAVR and native-TAVR groups at 1 year (1·8% vs 3·3%, p=0·18). Death or stroke after redo-TAVR were not significantly affected by the timing of redo-TAVR (before or after 1 year of index TAVR), or by index transcatheter valve type (balloon-expandable or non-balloon-expandable). INTERPRETATION: Redo-TAVR with balloon-expandable valves effectively treated dysfunction of the index TAVR procedure with low procedural complication rates, and death and stroke rates similar to those in patients with a similar clinical profile and predicted risk undergoing TAVR for native aortic valve stenosis. Redo-TAVR with balloon-expandable valves might be a reasonable treatment for failed TAVR in selected patients. FUNDING: Edwards Lifesciences.


Asunto(s)
Estenosis de la Válvula Aórtica , Prótesis Valvulares Cardíacas , Accidente Cerebrovascular , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Masculino , Femenino , Anciano , Reemplazo de la Válvula Aórtica Transcatéter/métodos , Prótesis Valvulares Cardíacas/efectos adversos , Resultado del Tratamiento , Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/cirugía , Accidente Cerebrovascular/etiología , Sistema de Registros , Factores de Riesgo , Diseño de Prótesis
16.
N Engl J Med ; 384(18): 1719-1730, 2021 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-33951361

RESUMEN

BACKGROUND: Weight regain after weight loss is a major problem in the treatment of persons with obesity. METHODS: In a randomized, head-to-head, placebo-controlled trial, we enrolled adults with obesity (body-mass index [the weight in kilograms divided by the square of the height in meters], 32 to 43) who did not have diabetes. After an 8-week low-calorie diet, participants were randomly assigned for 1 year to one of four strategies: a moderate-to-vigorous-intensity exercise program plus placebo (exercise group); treatment with liraglutide (3.0 mg per day) plus usual activity (liraglutide group); exercise program plus liraglutide therapy (combination group); or placebo plus usual activity (placebo group). End points with prespecified hypotheses were the change in body weight (primary end point) and the change in body-fat percentage (secondary end point) from randomization to the end of the treatment period in the intention-to-treat population. Prespecified metabolic health-related end points and safety were also assessed. RESULTS: After the 8-week low-calorie diet, 195 participants had a mean decrease in body weight of 13.1 kg. At 1 year, all the active-treatment strategies led to greater weight loss than placebo: difference in the exercise group, -4.1 kg (95% confidence interval [CI], -7.8 to -0.4; P = 0.03); in the liraglutide group, -6.8 kg (95% CI, -10.4 to -3.1; P<0.001); and in the combination group, -9.5 kg (95% CI, -13.1 to -5.9; P<0.001). The combination strategy led to greater weight loss than exercise (difference, -5.4 kg; 95% CI, -9.0 to -1.7; P = 0.004) but not liraglutide (-2.7 kg; 95% CI, -6.3 to 0.8; P = 0.13). The combination strategy decreased body-fat percentage by 3.9 percentage points, which was approximately twice the decrease in the exercise group (-1.7 percentage points; 95% CI, -3.2 to -0.2; P = 0.02) and the liraglutide group (-1.9 percentage points; 95% CI, -3.3 to -0.5; P = 0.009). Only the combination strategy was associated with improvements in the glycated hemoglobin level, insulin sensitivity, and cardiorespiratory fitness. Increased heart rate and cholelithiasis were observed more often in the liraglutide group than in the combination group. CONCLUSIONS: A strategy combining exercise and liraglutide therapy improved healthy weight loss maintenance more than either treatment alone. (Funded by the Novo Nordisk Foundation and others; EudraCT number, 2015-005585-32; ClinicalTrials.gov number, NCT04122716.).


Asunto(s)
Fármacos Antiobesidad/uso terapéutico , Terapia por Ejercicio , Liraglutida/uso terapéutico , Obesidad/terapia , Pérdida de Peso , Tejido Adiposo , Adulto , Fármacos Antiobesidad/efectos adversos , Tamaño Corporal , Restricción Calórica , Terapia Combinada , Femenino , Humanos , Liraglutida/efectos adversos , Masculino , Persona de Mediana Edad , Obesidad/dietoterapia , Obesidad/tratamiento farmacológico , Pérdida de Peso/efectos de los fármacos
17.
Am Heart J ; 268: 94-103, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38056546

RESUMEN

BACKGROUND: For patients with asymptomatic, severe aortic stenosis (AS) and preserved left ventricular ejection fraction, current guidelines recommend clinical surveillance every 6 to 12 months. To date, no randomized trials have examined whether an early intervention with transcatheter aortic valve replacement (TAVR) will improve outcomes among these patients. STUDY DESIGN AND OBJECTIVES: EARLY TAVR is a prospective, randomized, controlled, and multicenter trial, with an event-based design. Asymptomatic severe AS patients (n = 900) are randomized 1:1 to either clinical surveillance or TAVR with the Edwards SAPIEN 3/SAPIEN 3 Ultra transcatheter heart valve. Patients are stratified by whether they are able to perform a treadmill stress test. The primary end point is death, stroke, or unplanned cardiovascular hospitalization. Patients who are asymptomatic but have a positive stress test will be followed in a registry and undergo aortic valve replacement as per current guidelines. CONCLUSIONS: EARLY TAVR is the largest randomized trial to date assessing the role of early intervention among patients with asymptomatic severe AS compared to clinical surveillance and the first to study the role of TAVR. TRIAL REGISTRATION NUMBER: NCT03042104.


Asunto(s)
Estenosis de la Válvula Aórtica , Implantación de Prótesis de Válvulas Cardíacas , Prótesis Valvulares Cardíacas , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Estenosis de la Válvula Aórtica/epidemiología , Volumen Sistólico , Estudios Prospectivos , Factores de Riesgo , Resultado del Tratamiento , Función Ventricular Izquierda , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Índice de Severidad de la Enfermedad
18.
Crit Care Med ; 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38899947

RESUMEN

OBJECTIVES: Critically ill adults requiring artificial airways experience profound communication deficits. Studies of interventions supporting communication report disparate outcomes, creating subsequent challenges in the interpretation of their effectiveness. Therefore, we aimed to develop international consensus for a communication core outcome set (Comm-COS) for future trials of communication interventions in this population. DESIGN: 1) Systematic review, 2) patient/family interviews, 3) two-round modified Delphi, and 4) virtual consensus meetings with a final voting round. A multidisciplinary expert steering committee oversaw all stages. SETTING: Interviews and consensus meetings were conducted via videoconferencing. Digital methods were used for Delphi and final Comm-COS voting. SUBJECTS: Three stakeholder groups: 1) patient and family members with lived experience within 3 years, 2) clinicians with experience working in critical care, and 3) researchers publishing in the field. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: We identified 59 outcomes via our systematic review, 3 unique outcomes from qualitative interviews, and 2 outcomes from our steering committee. Following item reduction, 32 outcomes were presented in Delphi round 1; 134 participants voted; 15 patient/family (11%), 91 clinicians (68%), and 28 researchers (21%). Nine additional outcomes were generated and added to round 2; 106 (81%) participants voted. Following completion of the consensus processes, the Comm-COS includes seven outcomes: 1) changes in emotions and wellbeing associated with ability to communicate, 2) physical impact of communication aid use, 3) time to functional communication, 4) ability to communicate healthcare needs (comfort/care/safety/decisions), 5) conversation agency, 6) ability to establish a communication connection to develop and maintain relationships, and 7) acceptability of the communication intervention. CONCLUSIONS: This is the first COS to specifically focus on communication for critically ill adults. Limitations for operationalization include selection of measures to use with these outcomes. Identification of suitable measures and adoption of the Comm-COS in future trials will help establish effective interventions to ameliorate the highly prevalent and negative experience of communicative incapacity.

19.
Int J Med Microbiol ; 314: 151607, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38367508

RESUMEN

Measles is a highly contagious airborne viral disease. It can lead to serious complications and death and is preventable by vaccination. The live-attenuated measles vaccine (LAMV) derived from a measles virus (MV) isolated in 1954 has been in use globally for six decades and protects effectively by providing a durable humoral and cell-mediated immunity. Our study addresses the temporal stability of epitopes on the viral surface glycoprotein hemagglutinin (H) which is the major target of MV-neutralizing antibodies. We investigated the binding of seven vaccine-induced MV-H-specific monoclonal antibodies (mAbs) to cell-free synthesized MV-H proteins derived from the H gene sequences obtained from a lung specimen of a fatal case of measles pneumonia in 1912 and an isolate from a current case. The binding of four out of seven mAbs to the H protein of both MV strains provides evidence of epitopes that are stable for more than 100 years. The binding of the universally neutralizing mAbs RKI-MV-12b and RKI-MV-34c to the H protein of the 1912 MV suggests the long-term stability of highly conserved epitopes on the MV surface.


Asunto(s)
Virus del Sarampión , Sarampión , Humanos , Virus del Sarampión/genética , Anticuerpos Neutralizantes , Pruebas de Neutralización , Vacuna Antisarampión/genética , Sarampión/prevención & control , Anticuerpos Antivirales , Epítopos/genética , Hemaglutininas Virales/genética , Anticuerpos Monoclonales
20.
Phys Rev Lett ; 132(25): 250801, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38996246

RESUMEN

We present a quantum sensing technique that utilizes a sequence of π pulses to cyclically drive the qubit dynamics along a geodesic path of adiabatic evolution. This approach effectively suppresses the effects of both decoherence noise and control errors while simultaneously removing unwanted resonance terms, such as higher harmonics and spurious responses commonly encountered in dynamical decoupling control. As a result, our technique offers robust, wide-band, unambiguous, and high-resolution quantum sensing capabilities for signal detection and individual addressing of quantum systems, including spins. To demonstrate its versatility, we showcase successful applications of our method in both low-frequency and high-frequency sensing scenarios. The significance of this quantum sensing technique extends to the detection of complex signals and the control of intricate quantum environments. By enhancing detection accuracy and enabling precise manipulation of quantum systems, our method holds considerable promise for a variety of practical applications.

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