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1.
EMBO J ; 42(18): e113190, 2023 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-37492888

RESUMEN

DNA single-strand breaks (SSBs) disrupt DNA replication and induce chromosome breakage. However, whether SSBs induce chromosome breakage when present behind replication forks or ahead of replication forks is unclear. To address this question, we exploited an exquisite sensitivity of SSB repair-defective human cells lacking PARP activity or XRCC1 to the thymidine analogue 5-chloro-2'-deoxyuridine (CldU). We show that incubation with CldU in these cells results in chromosome breakage, sister chromatid exchange, and cytotoxicity by a mechanism that depends on the S phase activity of uracil DNA glycosylase (UNG). Importantly, we show that CldU incorporation in one cell cycle is cytotoxic only during the following cell cycle, when it is present in template DNA. In agreement with this, while UNG induces SSBs both in nascent strands behind replication forks and in template strands ahead of replication forks, only the latter trigger fork collapse and chromosome breakage. Finally, we show that BRCA-defective cells are hypersensitive to CldU, either alone and/or in combination with PARP inhibitor, suggesting that CldU may have clinical utility.


Asunto(s)
Antineoplásicos , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Humanos , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Rotura Cromosómica , Reparación del ADN , Replicación del ADN , ADN , Proteína 1 de Reparación por Escisión del Grupo de Complementación Cruzada de las Lesiones por Rayos X/metabolismo
2.
Nature ; 598(7882): 662-666, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34616044

RESUMEN

The availability of L-arginine in tumours is a key determinant of an efficient anti-tumour T cell response1-4. Consequently, increases of typically low L-arginine concentrations within the tumour may greatly potentiate the anti-tumour responses of immune checkpoint inhibitors, such as programmed death-ligand 1 (PD-L1)-blocking antibodies5. However, currently no means are available to locally increase intratumoural L-arginine levels. Here we used a synthetic biology approach to develop an engineered probiotic Escherichia coli Nissle 1917 strain that colonizes tumours and continuously converts ammonia, a metabolic waste product that accumulates in tumours6, to L-arginine. Colonization of tumours with these bacteria increased intratumoural L-arginine concentrations, increased the number of tumour-infiltrating T cells and had marked synergistic effects with PD-L1 blocking antibodies in the clearance of tumours. The anti-tumour effect of these bacteria was mediated by L-arginine and was dependent on T cells. These results show that engineered microbial therapies enable metabolic modulation of the tumour microenvironment leading to enhanced efficacy of immunotherapies.


Asunto(s)
Inmunoterapia/métodos , Ingeniería Metabólica , Microorganismos Modificados Genéticamente , Neoplasias Experimentales/terapia , Traslado Adoptivo , Animales , Arginina/metabolismo , Antígeno B7-H1/antagonistas & inhibidores , Línea Celular Tumoral , Escherichia coli , Femenino , Linfocitos Infiltrantes de Tumor/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/microbiología , Probióticos , Proteoma , Biología Sintética , Linfocitos T/inmunología , Microambiente Tumoral/inmunología
3.
Nature ; 599(7885): 421-424, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34789902

RESUMEN

Californium (Cf) is currently the heaviest element accessible above microgram quantities. Cf isotopes impose severe experimental challenges due to their scarcity and radiological hazards. Consequently, chemical secrets ranging from the accessibility of 5f/6d valence orbitals to engage in bonding, the role of spin-orbit coupling in electronic structure, and reactivity patterns compared to other f elements, remain locked. Organometallic molecules were foundational in elucidating periodicity and bonding trends across the periodic table1-3, with a twenty-first-century renaissance of organometallic thorium (Th) through plutonium (Pu) chemistry4-12, and to a smaller extent americium (Am)13, transforming chemical understanding. Yet, analogous curium (Cm) to Cf chemistry has lain dormant since the 1970s. Here, we revive air-/moisture-sensitive Cf chemistry through the synthesis and characterization of [Cf(C5Me4H)2Cl2K(OEt2)]n from two milligrams of 249Cf. This bent metallocene motif, not previously structurally authenticated beyond uranium (U)14,15, contains the first crystallographically characterized Cf-C bond. Analysis suggests the Cf-C bond is largely ionic with a small covalent contribution. Lowered Cf 5f orbital energy versus dysprosium (Dy) 4f in the colourless, isoelectronic and isostructural [Dy(C5Me4H)2Cl2K(OEt2)]n results in an orange Cf compound, contrasting with the light-green colour typically associated with Cf compounds16-22.

4.
Circulation ; 149(9): 658-668, 2024 02 27.
Artículo en Inglés | MEDLINE | ID: mdl-38084590

RESUMEN

BACKGROUND: Deep hypothermia has been the standard for hypothermic circulatory arrest (HCA) during aortic arch surgery. However, centers worldwide have shifted toward lesser hypothermia with antegrade cerebral perfusion. This has been supported by retrospective data, but there has yet to be a multicenter, prospective randomized study comparing deep versus moderate hypothermia during HCA. METHODS: This was a randomized single-blind trial (GOT ICE [Cognitive Effects of Body Temperature During Hypothermic Circulatory Arrest]) of patients undergoing arch surgery with HCA plus antegrade cerebral perfusion at 4 US referral aortic centers (August 2016-December 2021). Patients were randomized to 1 of 3 hypothermia groups: DP, deep (≤20.0 °C); LM, low-moderate (20.1-24.0 °C); and HM, high-moderate (24.1-28.0 °C). The primary outcome was composite global cognitive change score between baseline and 4 weeks postoperatively. Analysis followed the intention-to-treat principle to evaluate if: (1) LM noninferior to DP on global cognitive change score; (2) DP superior to HM. The secondary outcomes were domain-specific cognitive change scores, neuroimaging findings, quality of life, and adverse events. RESULTS: A total of 308 patients consented; 282 met inclusion and were randomized. A total of 273 completed surgery, and 251 completed the 4-week follow-up (DP, 85 [34%]; LM, 80 [34%]; HM, 86 [34%]). Mean global cognitive change score from baseline to 4 weeks in the LM group was noninferior to the DP group; likewise, no significant difference was observed between DP and HM. Noninferiority of LM versus DP, and lack of difference between DP and HM, remained for domain-specific cognitive change scores, except structured verbal memory, with noninferiority of LM versus DP not established and structured verbal memory better preserved in DP versus HM (P = 0.036). There were no significant differences in structural or functional magnetic resonance imaging brain imaging between groups postoperatively. Regardless of temperature, patients who underwent HCA demonstrated significant reductions in cerebral gray matter volume, cortical thickness, and regional brain functional connectivity. Thirty-day in-hospital mortality, major morbidity, and quality of life were not different between groups. CONCLUSIONS: This randomized multicenter study evaluating arch surgery HCA temperature strategies found low-moderate hypothermia noninferior to traditional deep hypothermia on global cognitive change 4 weeks after surgery, although in secondary analysis, structured verbal memory was better preserved in the deep group. The verbal memory differences in the low- and high-moderate groups and structural and functional connectivity reductions from baseline merit further investigation and suggest opportunities to further optimize brain perfusion during HCA. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02834065.


Asunto(s)
Aorta Torácica , Hipotermia , Humanos , Aorta Torácica/diagnóstico por imagen , Aorta Torácica/cirugía , Estudios Retrospectivos , Estudios Prospectivos , Calidad de Vida , Método Simple Ciego , Temperatura Corporal , Paro Circulatorio Inducido por Hipotermia Profunda/efectos adversos , Perfusión/efectos adversos , Perfusión/métodos , Cognición , Circulación Cerebrovascular , Resultado del Tratamiento
5.
Ann Neurol ; 95(2): 325-337, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37787451

RESUMEN

OBJECTIVE: Genome-wide association studies have identified 1q22 as a susceptibility locus for cerebral small vessel diseases, including non-lobar intracerebral hemorrhage (ICH) and lacunar stroke. In the present study, we performed targeted high-depth sequencing of 1q22 in ICH cases and controls to further characterize this locus and prioritize potential causal mechanisms, which remain unknown. METHODS: A total of 95,000 base pairs spanning 1q22, including SEMA4A, SLC25A44, and PMF1/PMF1-BGLAP were sequenced in 1,055 spontaneous ICH cases (534 lobar and 521 non-lobar) and 1,078 controls. Firth regression and Rare Variant Influential Filtering Tool analysis were used to analyze common and rare variants, respectively. Chromatin interaction analyses were performed using Hi-C, chromatin immunoprecipitation followed by sequencing, and chromatin interaction analysis with paired-end tag databases. Multivariable Mendelian randomization assessed whether alterations in gene-specific expression relative to regionally co-expressed genes at 1q22 could be causally related to ICH risk. RESULTS: Common and rare variant analyses prioritized variants in SEMA4A 5'-UTR and PMF1 intronic regions, overlapping with active promoter and enhancer regions based on ENCODE annotation. Hi-C data analysis determined that 1q22 is spatially organized in a single chromatin loop, and that the genes therein belong to the same topologically associating domain. Chromatin immunoprecipitation followed by sequencing and chromatin interaction analysis with paired-end tag data analysis highlighted the presence of long-range interactions between the SEMA4A-promoter and PMF1-enhancer regions prioritized by association testing. Multivariable Mendelian randomization analyses demonstrated that PMF1 overexpression could be causally related to non-lobar ICH risk. INTERPRETATION: Altered promoter-enhancer interactions leading to PMF1 overexpression, potentially dysregulating polyamine catabolism, could explain demonstrated associations with non-lobar ICH risk at 1q22, offering a potential new target for prevention of ICH and cerebral small vessel disease. ANN NEUROL 2024;95:325-337.


Asunto(s)
Enfermedades de los Pequeños Vasos Cerebrales , Semaforinas , Accidente Vascular Cerebral Lacunar , Humanos , Estudio de Asociación del Genoma Completo , Hemorragia Cerebral/genética , Hemorragia Cerebral/complicaciones , Enfermedades de los Pequeños Vasos Cerebrales/genética , Enfermedades de los Pequeños Vasos Cerebrales/complicaciones , Accidente Vascular Cerebral Lacunar/complicaciones , Cromatina , Semaforinas/genética
6.
J Gen Virol ; 105(1)2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38175123

RESUMEN

Hepatitis B Virus (HBV) is a small DNA virus that replicates via an episomal covalently closed circular DNA (cccDNA) that serves as the transcriptional template for viral mRNAs. The host protein, CCCTC-binding factor (CTCF), is a key regulator of cellular transcription by maintaining epigenetic boundaries, nucleosome phasing, stabilisation of long-range chromatin loops and directing alternative exon splicing. We previously reported that CTCF binds two conserved motifs within Enhancer I of the HBV genome and represses viral transcription, however, the underlying mechanisms were not identified. We show that CTCF depletion in cells harbouring cccDNA-like HBV molecules and in de novo infected cells resulted in an increase in spliced transcripts, which was most notable in the abundant SP1 spliced transcript. In contrast, depletion of CTCF in cell lines with integrated HBV DNA had no effect on the abundance of viral transcripts and in line with this observation there was limited evidence for CTCF binding to viral integrants, suggesting that CTCF-regulation of HBV transcription is specific to episomal cccDNA. Analysis of HBV chromatin topology by Assay for Transposase Accessible Chromatin Sequencing (ATAC-Seq) revealed an accessible region spanning Enhancers I and II and the basal core promoter (BCP). Mutating the CTCF binding sites within Enhancer I resulted in a dramatic rearrangement of chromatin accessibility where the open chromatin region was no longer detected, indicating loss of the phased nucleosome up- and down-stream of the HBV enhancer/BCP. These data demonstrate that CTCF functions to regulate HBV chromatin conformation and nucleosomal positioning in episomal maintained cccDNA, which has important consequences for HBV transcription regulation.


Asunto(s)
Cromatina , Virus de la Hepatitis B , Cromatina/genética , Virus de la Hepatitis B/genética , ADN Circular/genética , Nucleosomas , Factor de Unión a CCCTC/genética
7.
Crit Care Med ; 52(4): 607-617, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-37966330

RESUMEN

OBJECTIVE: To examine early sedation patterns, as well as the association of dexmedetomidine exposure, with clinical and functional outcomes among mechanically ventilated patients with moderate-severe traumatic brain injury (msTBI). DESIGN: Retrospective cohort study with prospectively collected data. SETTING: Eighteen Level-1 Trauma Centers, United States. PATIENTS: Adult (age > 17) patients with msTBI (as defined by Glasgow Coma Scale < 13) who required mechanical ventilation from the Transforming Clinical Research and Knowledge in TBI (TRACK-TBI) study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Using propensity-weighted models, we examined the association of early dexmedetomidine exposure (within the first 5 d of ICU admission) with the primary outcome of 6-month Glasgow Outcomes Scale Extended (GOS-E) and the following secondary outcomes: length of hospital stay, hospital mortality, 6-month Disability Rating Scale (DRS), and 6-month mortality. The study population included 352 subjects who required mechanical ventilation within 24 hours of admission. The initial sedative medication was propofol for 240 patients (68%), midazolam for 59 patients (17%), ketamine for 6 patients (2%), dexmedetomidine for 3 patients (1%), and 43 patients (12%) never received continuous sedation. Early dexmedetomidine was administered in 77 of the patients (22%), usually as a second-line agent. Compared with unexposed patients, early dexmedetomidine exposure was not associated with better 6-month GOS-E (weighted odds ratio [OR] = 1.48; 95% CI, 0.98-2.25). Early dexmedetomidine exposure was associated with lower DRS (weighted OR = -3.04; 95% CI, -5.88 to -0.21). In patients requiring ICP monitoring within the first 24 hours of admission, early dexmedetomidine exposure was associated with higher 6-month GOS-E score (OR 2.17; 95% CI, 1.24-3.80), lower DRS score (adjusted mean difference, -5.81; 95% CI, -9.38 to 2.25), and reduced length of hospital stay (hazard ratio = 1.50; 95% CI, 1.02-2.20). CONCLUSION: Variation exists in early sedation choice among mechanically ventilated patients with msTBI. Early dexmedetomidine exposure was not associated with improved 6-month functional outcomes in the entire population, although may have clinical benefit in patients with indications for ICP monitoring.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Dexmedetomidina , Propofol , Adulto , Humanos , Dexmedetomidina/uso terapéutico , Estudios Retrospectivos , Hipnóticos y Sedantes/uso terapéutico , Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Lesiones Traumáticas del Encéfalo/complicaciones , Propofol/uso terapéutico , Respiración Artificial
8.
Chemphyschem ; : e202400515, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38973286

RESUMEN

In recent years, halogen bond-based organocatalysis has garnered significant attention as an alternative to hydrogen-based catalysis, capturing considerable interest within the scientific community. This transition has witnessed the evolution of catalytic scaffolds from monodentate to bidentate architectures, and from monovalent to hypervalent species. In this DFT-based study, we explored a bidentate hypervalent iodine(III)-based system that has already undergone experimental validation. Additionally, we explore various functionalisations (-CF$_3$, -CH$_3$, -tBu, -OH, -OMe, -NO$_2$, -CN) and scaffold modifications, such as sulfur oxidation, theoretically proposed for an indole-based Michael addition. The investigated systems favour bidentate O-type binding, underlining the importance of ligand coordination in catalytic activity. Electron-deficient scaffolds exhibited stronger binding and lower activation energies, indicating the pivotal role of electronic properties for $\sigma$-hole-based catalysis. Of these groups, Lewis-base-like moieties formed stabilising intramolecular interactions with hypervalent iodines when in the ortho-position. Furthermore, inductive electron withdrawal was deemed more effective than mesomeric withdrawal in enhancing catalytic efficacy for these systems. Lastly, increasing sulfur oxidation was theoretically proven to improve catalytic activity significantly.

9.
Org Biomol Chem ; 22(30): 6166-6173, 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39012651

RESUMEN

Computational analysis of organic radical species presents significant challenges. This study compares the efficacy of various DFT and wavefunction methods in predicting radical stabilisation energies, bond dissociation energies, and redox potentials for organic radicals. The hybrid meta-GGA M062X-D3(0), and the range-separated hybrids ωB97M-V and ωB97M-D3(BJ) emerged as the most reliable functionals, consistently providing accurate predictions across different basis sets including 6-311G**, cc-pVTZ, and def2-TZVP.

10.
J Intensive Care Med ; 39(9): 875-882, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38449336

RESUMEN

BACKGROUND: There is limited evidence that beta-blockers may provide benefit for patients with moderate-severe traumatic brain injury (TBI) during the acute injury period. Larger studies on utilization patterns and impact on outcomes in clinical practice are lacking. OBJECTIVE: The present study uses a large, national hospital claims-based dataset to examine early beta-blocker utilization patterns and its association with clinical outcomes among critically ill patients with moderate-severe TBI. METHODS: We conducted a retrospective cohort study of the administrative claims Premier Healthcare Database of adults (≥17 years) with moderate-severe TBI admitted to the intensive care unit (ICU) from 2016 to 2020. The exposure was receipt of a beta-blocker during day 1 or 2 of ICU stay (BB+). The primary outcome was hospital mortality, and secondary outcomes were: hospital length of stay (LOS), ICU LOS, discharge to home, and vasopressor utilization. In a sensitivity analysis, we explored the association of beta-blocker class (cardioselective and noncardioselective) with hospital mortality. We used propensity weighting methods to address possible confounding by treatment indication. RESULTS: A total of 109 665 participants met inclusion criteria and 39% (n = 42 489) were exposed to beta-blockers during the first 2 days of hospitalization. Of those, 42% received cardioselective only, 43% received noncardioselective only, and 14% received both. After adjustment, there was no association with hospital mortality in the BB+ group compared to the BB- group (adjusted odds ratio [OR] = 0.99, 95% confidence interval [CI] = 0.94, 1.04). The BB+ group had longer hospital stays, lower chance of discharged home, and lower risk of vasopressor utilization, although these difference were clinically small. Beta-blocker class was not associated with hospital mortality. CONCLUSION: In this retrospective cohort study, we found variation in use of beta-blockers and early exposure was not associated with hospital mortality. Further research is necessary to understand the optimal type, dose, and timing of beta-blockers for this population.


Asunto(s)
Antagonistas Adrenérgicos beta , Lesiones Traumáticas del Encéfalo , Enfermedad Crítica , Mortalidad Hospitalaria , Unidades de Cuidados Intensivos , Tiempo de Internación , Humanos , Antagonistas Adrenérgicos beta/uso terapéutico , Estudios Retrospectivos , Lesiones Traumáticas del Encéfalo/mortalidad , Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Masculino , Femenino , Persona de Mediana Edad , Enfermedad Crítica/mortalidad , Tiempo de Internación/estadística & datos numéricos , Adulto , Unidades de Cuidados Intensivos/estadística & datos numéricos , Anciano , Puntaje de Propensión
11.
Anesth Analg ; 139(2): 366-374, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38335145

RESUMEN

BACKGROUND: Traumatic brain injury (TBI) is an expensive and common public health problem. Management of TBI oftentimes includes sedation to facilitate mechanical ventilation (MV) for airway protection. Dexmedetomidine has emerged as a potential candidate for improved patient outcomes when used for early sedation after TBI due to its potential modulation of autonomic dysfunction. We examined early sedation patterns, as well as the association of dexmedetomidine exposure with clinical and functional outcomes among mechanically ventilated patients with moderate-severe TBI (msTBI) in the United States. METHODS: We conducted a retrospective cohort study using data from the Premier dataset and identified a cohort of critically ill adult patients with msTBI who required MV from January 2016 to June 2020. msTBI was defined by head-neck abbreviated injury scale (AIS) values of 3 (serious), 4 (severe), and 5 (critical). We described early continuous sedative utilization patterns. Using propensity-matched models, we examined the association of early dexmedetomidine exposure (within 2 days of intensive care unit [ICU] admission) with the primary outcome of hospital mortality and the following secondary outcomes: hospital length of stay (LOS), days on MV, vasopressor use after the first 2 days of admission, hemodialysis (HD) after the first 2 days of admission, hospital costs, and discharge disposition. All medications, treatments, and procedures were identified using date-stamped hospital charge codes. RESULTS: The study population included 19,751 subjects who required MV within 2 days of ICU admission. The patients were majority male and white. From 2016 to 2020, the annual percent utilization of dexmedetomidine increased from 4.05% to 8.60%. After propensity score matching, early dexmedetomidine exposure was associated with reduced odds of hospital mortality (odds ratio [OR], 0.59; 95% confidence interval [CI], 0.47-0.74; P < .0001), increased risk for liberation from MV (hazard ratio [HR], 1.20; 95% CI, 1.09-1.33; P = .0003), and reduced LOS (HR, 1.11; 95% CI, 1.01-1.22; P = .033). Exposure to early dexmedetomidine was not associated with odds of HD (OR, 1.14; 95% CI, 0.73-1.78; P = .56), vasopressor utilization (OR, 1.10; 95% CI, 0.78-1.55; P = .60), or increased hospital costs (relative cost ratio, 1.98; 95% CI, 0.93-1.03; P = .66). CONCLUSIONS: Dexmedetomidine is being utilized increasingly as a sedative for mechanically ventilated patients with msTBI. Early dexmedetomidine exposure may lead to improved patient outcomes in this population.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Dexmedetomidina , Mortalidad Hospitalaria , Hipnóticos y Sedantes , Respiración Artificial , Humanos , Dexmedetomidina/uso terapéutico , Dexmedetomidina/efectos adversos , Estudios Retrospectivos , Masculino , Lesiones Traumáticas del Encéfalo/mortalidad , Lesiones Traumáticas del Encéfalo/diagnóstico , Femenino , Persona de Mediana Edad , Hipnóticos y Sedantes/uso terapéutico , Hipnóticos y Sedantes/efectos adversos , Adulto , Resultado del Tratamiento , Anciano , Tiempo de Internación , Factores de Tiempo , Estados Unidos/epidemiología , Bases de Datos Factuales , Estudios de Cohortes
12.
Proc Natl Acad Sci U S A ; 118(30)2021 07 27.
Artículo en Inglés | MEDLINE | ID: mdl-34301902

RESUMEN

Uncovering the basis of small-molecule hormone receptors' evolution is paramount to a complete understanding of how protein structure drives function. In plants, hormone receptors for strigolactones are well suited to evolutionary inquiries because closely related homologs have different ligand preferences. More importantly, because of facile plant transgenic systems, receptors can be swapped and quickly assessed functionally in vivo. Here, we show that only three mutations are required to turn the nonstrigolactone receptor, KAI2, into a receptor that recognizes the plant hormone strigolactone. This modified receptor still retains its native function to perceive KAI2 ligands. Our directed evolution studies indicate that only a few keystone mutations are required to increase receptor promiscuity of KAI2, which may have implications for strigolactone receptor evolution in parasitic plants.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Furanos/metabolismo , Regulación de la Expresión Génica de las Plantas/fisiología , Compuestos Heterocíclicos con 3 Anillos/metabolismo , Hidrolasas/metabolismo , Lactonas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Piranos/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Hidrolasas/genética , Mutación , Filogenia , Unión Proteica
13.
Arthroscopy ; 40(2): 422-423, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38296445

RESUMEN

Primary meniscal allograft transplantation (PMAT) is an effective yet sometimes short-term solution to postmeniscectomy syndrome. Survivorship beyond 10 years can carry a guarded prognosis. Alternatives after failure of PMAT are typically total or unicompartmental arthroplasty, which, depending on desired activity level, can be reasonable options for older patients. However, when faced with younger, otherwise healthy patients, revision meniscal allograft transplantation (RMAT) shows outcomes in appropriately indicated patients when concomitant pathology is also addressed. Patient expectations must be tempered (i.e., they should not expect to achieve an International Knee Documentation Committee score of 70 to 100, but rather 40 to 70 meaning that a patient can function reasonably well in activities of daily living). Thus RMAT is a viable "salvage" or "bridge" option in the hands of experienced high-volume knee surgeons (to ensure meticulous surgical technique and the ability to perform all necessary concomitant procedures). Patients must have appropriate expectations and be appropriately indicated.


Asunto(s)
Actividades Cotidianas , Meniscos Tibiales , Humanos , Meniscos Tibiales/trasplante , Motivación , Estudios de Seguimiento , Articulación de la Rodilla/cirugía , Aloinjertos
14.
J Shoulder Elbow Surg ; 33(6S): S104-S110, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38485082

RESUMEN

BACKGROUND: Reverse total shoulder arthroplasty (RSA) has been increasingly utilized for a variety of shoulder pathologies that are difficult to treat with anatomical total shoulder arthroplasty (TSA). Few studies have compared the outcomes of TSA vs. RSA in patients with cuff intact glenohumeral osteoarthritis and poor preoperative forward elevation. This study aimed to determine whether there is a difference in functional outcomes and postoperative range of motion (ROM) between TSA and RSA in these patients. METHODS: This retrospective cohort study included 116 patients who underwent RSA or TSA between 2013 and 2022 for the treatment of rotator cuff intact primary osteoarthritis with restricted preoperative forward flexion (FF) and a minimum 1-year follow-up. Each arthroplasty group was divided into 2 subgroups: patients with preoperative FF between 91° and 120° or FF lower than or equal to 90°. Patients' clinical outcomes, including active ROM, American Shoulder and Elbow Surgeons score, visual analog scale for pain, and subjective shoulder value were collected. Clinical and radiographic complications were evaluated. RESULTS: There was no significant difference between RSA and TSA in terms of sex (58.3% male vs. 62.2% male, P = .692), or follow-up duration (20.1 months vs. 17.7 months, P = .230). However, the RSA cohort was significantly older (72.0 ± 8.2 vs. 65.4 ± 10.6, P = .012) and weaker in FF and (ER) before surgery (P < .001). There was no difference between RSA (57 patients) and TSA (59 patients) in visual analog scale pain score (1.2 ± 2.3 vs. 1.3 ± 2.3, P = .925), subjective shoulder value score (90 ± 15 vs. 90 ± 15, P = .859), or American Shoulder and Elbow Surgeons score (78.4 ± 20.5 vs. 82.1 ± 23.2, P = .476). Postoperative active ROM was statistically similar between RSA and TSA cohorts in FF (145 ± 26 vs. 146 ± 23, P = .728) and ER (39 ± 15 vs. 41 ± 15, P = .584). However, internal rotation was lower in the RSA cohort (P < .001). This was also true in each subgroup. RSA led to faster postoperative FF and ER achievement at 3 months (P < .001). There was no statistically significant difference in complication rates between cohorts. CONCLUSION: This study demonstrates that patients with glenohumeral osteoarthritis who have a structurally intact rotator cuff but limited preoperative forward elevation can achieve predictable clinical improvement in pain, ROM, and function after either TSA or RSA. Reverse arthroplasty may be a reliable treatment option in patients at risk for developing rotator cuff failure.


Asunto(s)
Artroplastía de Reemplazo de Hombro , Osteoartritis , Rango del Movimiento Articular , Recuperación de la Función , Articulación del Hombro , Humanos , Masculino , Femenino , Artroplastía de Reemplazo de Hombro/métodos , Estudios Retrospectivos , Osteoartritis/cirugía , Osteoartritis/fisiopatología , Anciano , Persona de Mediana Edad , Articulación del Hombro/cirugía , Articulación del Hombro/fisiopatología , Resultado del Tratamiento
15.
J Shoulder Elbow Surg ; 33(6S): S16-S24, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38104716

RESUMEN

INTRODUCTION: Recent studies have defined pseudoparesis as limited active forward elevation between 45° and 90° and maintained passive range of motion (ROM) in the setting of a massive rotator cuff tear (RCT). Although pseudoparesis can be reliably reversed with reverse total shoulder arthroplasty (RSA) or superior capsular reconstruction (SCR), the optimal treatment for this indication remains unknown. The purpose of this study was to compare the clinical outcomes of RSA to SCR in patients with pseudoparesis secondary to massive, irreparable RCT (miRCT). METHODS: This was a retrospective cohort study of consecutive patients aged 40-70 years with pseudoparesis secondary to miRCT who were treated with either RSA or SCR by a single fellowship-trained shoulder surgeon from 2016 to 2021 with a minimum 12-month follow-up. Multivariate linear regression modeling was used to compare active ROM, visual analog pain scale (VAS), Subjective Shoulder Value (SSV), and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score between RSA and SCR while controlling for confounding variables. RESULTS: Twenty-seven patients were included in the RSA cohort and 23 patients were included in the SCR cohort with similar mean follow-up times (26.2 ± 21.1 vs. 21.9 ± 14.7 months, respectively). The patients in the RSA group were significantly older than those in the SCR group (65.2 ± 4.4 vs. 54.2 ± 7.8 years, P < .001) and had more severe arthritis (1.8 ± 0.9 vs. 1.2 ± 0.5 Samilson-Prieto, P = .019). The pseudoparesis reversal rate among the RSA and SCR cohorts was 96.3% and 91.3%, respectively. On univariate analysis, the RSA cohort demonstrated significantly greater mean improvement in active FF (89° ± 26° vs. 73° ± 30° change, P = .048), greater postoperative SSV (91 ± 8% vs. 69 ± 25%, P < .001), lower postoperative VAS pain scores (0.6 ± 1.2 vs. 2.2 ± 2.9, P = .020), and less postoperative internal rotation (IR; 4.6° ± 1.6° vs. 6.9° ± 1.8°, P = .004) compared with SCR. On multivariate analysis controlling for age and osteoarthritis, RSA remained a significant predictor of greater SSV (ß = 21.5, P = .021) and lower VAS scores (ß = -1.4, P = .037), whereas SCR was predictive of greater IR ROM (ß = 3.0, P = .043). CONCLUSION: Although both RSA and SCR effectively reverse pseudoparesis, patients with RSA have higher SSV and lower pain scores but less IR after controlling for age and osteoarthritis. The results of this study may inform surgical decision making for patients who are suitable candidates for either procedure.


Asunto(s)
Artroplastía de Reemplazo de Hombro , Rango del Movimiento Articular , Lesiones del Manguito de los Rotadores , Humanos , Persona de Mediana Edad , Masculino , Femenino , Estudios Retrospectivos , Lesiones del Manguito de los Rotadores/cirugía , Lesiones del Manguito de los Rotadores/complicaciones , Anciano , Artroplastía de Reemplazo de Hombro/métodos , Adulto , Procedimientos de Cirugía Plástica/métodos , Resultado del Tratamiento , Cápsula Articular/cirugía
16.
PLoS Med ; 20(9): e1004278, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37682971

RESUMEN

BACKGROUND: Tuberculosis (TB) prevalence remains persistently high in many settings, with new or expanded interventions required to achieve substantial reductions. The HIV Prevention Trials Network (HPTN) 071 (PopART) community-randomised trial randomised 14 communities to receive the "PopART" intervention during 2014 to 2017 (7 arm A and 7 arm B communities) and 7 communities to receive standard-of-care (arm C). The intervention was delivered door-to-door by community HIV care providers (CHiPs) and included universal HIV testing, facilitated linkage to HIV care at government health clinics, and systematic TB symptom screening. The Tuberculosis Reduction through Expanded Anti-retroviral Treatment and Screening (TREATS) study aimed to measure the impact of delivering the PopART intervention on TB outcomes, in communities with high HIV and TB prevalence. METHODS AND FINDINGS: The study population of the HPTN 071 (PopART) trial included individuals aged ≥15 years living in 21 urban and peri-urban communities in Zambia and South Africa, with a total population of approximately 1 million and an adult HIV prevalence of around 15% at the time of the trial. Two sputum samples for TB testing were provided to CHiPs by individuals who reported ≥1 TB suggestive symptom (a cough for ≥2 weeks, unintentional weight loss ≥1.5 kg in the last month, or current night sweats) or that a household member was currently on TB treatment. Antiretroviral therapy (ART) was offered universally at clinics in arm A and according to local guidelines in arms B and C. The TREATS study was conducted in the same 21 communities as the HPTN 071 (PopART) trial between 2017 and 2022, and TB prevalence was a co-primary endpoint of the TREATS study. The primary comparison was between the PopART intervention (arms A and B combined) and the standard-of-care (arm C). During 2019 to 2021, a TB prevalence survey was conducted among randomly selected individuals aged ≥15 years (approximately 1,750 per community in arms A and B, approximately 3,500 in arm C). Participants were screened on TB symptoms and chest X-ray, with diagnostic testing using Xpert-Ultra followed by culture for individuals who screened positive. Sputum eligibility was determined by the presence of a cough for ≥2 weeks, or ≥2 of 5 "TB suggestive" symptoms (cough, weight loss for ≥4 weeks, night sweats, chest pain, and fever for ≥2 weeks), or chest X-ray CAD4TBv5 score ≥50, or no available X-ray results. TB prevalence was compared between trial arms using standard methods for cluster-randomised trials, with adjustment for age, sex, and HIV status, and multiple imputation was used for missing data on prevalent TB. Among 83,092 individuals who were eligible for the survey, 49,556 (59.6%) participated, 8,083 (16.3%) screened positive, 90.8% (7,336/8,083) provided 2 sputum samples for Xpert-Ultra testing, and 308 (4.2%) required culture confirmation. Overall, estimated TB prevalence was 0.92% (457/49,556). The geometric means of 7 community-level prevalence estimates were 0.91%, 0.70%, and 0.69% in arms A, B, and C, respectively, with no evidence of a difference comparing arms A and B combined with arm C (adjusted prevalence ratio 1.14, 95% confidence interval, CI [0.67, 1.95], p = 0.60). TB prevalence was higher among people living with HIV than HIV-negative individuals, with an age-sex-community adjusted odds ratio of 2.29 [95% CI 1.54, 3.41] in Zambian communities and 1.61 [95% CI 1.13, 2.30] in South African communities. The primary limitations are that the study was powered to detect only large reductions in TB prevalence in the intervention arm compared with standard-of-care, and the between-community variation in TB prevalence was larger than anticipated. CONCLUSIONS: There was no evidence that the PopART intervention reduced TB prevalence. Systematic screening for TB that is based on symptom screening alone may not be sufficient to achieve a large reduction in TB prevalence over a period of several years. Including chest X-ray screening alongside TB symptom screening could substantially increase the sensitivity of systematic screening for TB. TRIAL REGISTRATION: The TREATS study was registered with ClinicalTrials.gov Identifier: NCT03739736 on November 14, 2018. The HPTN 071 (PopART) trial was registered at ClinicalTrials.gov under number NCT01900977 on July 17, 2013.


Asunto(s)
Infecciones por VIH , VIH , Adulto , Humanos , Sudáfrica/epidemiología , Zambia/epidemiología , Estudios Transversales , Tos , Prevalencia , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Proyectos de Investigación
17.
Mol Syst Biol ; 18(3): e10539, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35253995

RESUMEN

Enteric hyperoxaluria (EH) is a metabolic disease caused by excessive absorption of dietary oxalate leading to the formation of chronic kidney stones and kidney failure. There are no approved pharmaceutical treatments for EH. SYNB8802 is an engineered bacterial therapeutic designed to consume oxalate in the gut and lower urinary oxalate as a potential treatment for EH. Oral administration of SYNB8802 leads to significantly decreased urinary oxalate excretion in healthy mice and non-human primates, demonstrating the strain's ability to consume oxalate in vivo. A mathematical modeling framework was constructed that combines in vitro and in vivo preclinical data to predict the effects of SYNB8802 administration on urinary oxalate excretion in humans. Simulations of SYNB8802 administration predict a clinically meaningful lowering of urinary oxalate excretion in healthy volunteers and EH patients. Together, these findings suggest that SYNB8802 is a promising treatment for EH.


Asunto(s)
Hiperoxaluria , Animales , Simulación por Computador , Femenino , Humanos , Hiperoxaluria/etiología , Hiperoxaluria/orina , Masculino , Ratones , Oxalatos/metabolismo , Oxalatos/orina
18.
Chemistry ; 29(16): e202203807, 2023 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-36594445

RESUMEN

A one-step method for the conversion of nitroarenes into phenols under operationally simple, transition-metal-free conditions is described. This denitrative functionalization protocol provides a concise and economical alternative to conventional three-step synthetic sequences. Experimental and computational studies suggest that nitroarenes may be substituted by an electron-catalysed radical-nucleophilic substitution (SRN 1) chain mechanism.

19.
J Magn Reson Imaging ; 58(5): 1462-1469, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-36995159

RESUMEN

BACKGROUND: Crossed cerebellar diaschisis (CCD) refers to depressions in perfusion and metabolism within the cerebellar hemisphere contralateral to supratentorial disease. Prior investigation into CCD in cerebrovascular reactivity (CVR) has been limited to terminal CVR estimations (CVRend ). We recently have demonstrated the presence of unsustained CVR maxima (CVRmax ) using dynamic CVR analysis, offering a fully dynamic characterization of CVR to hemodynamic stimuli. PURPOSE: To investigate CCD in CVRmax from dynamic blood oxygen level-dependent (BOLD) MRI, by comparison with conventional CVRend estimation. STUDY TYPE: Retrospective. POPULATION: A total of 23 patients (median age: 51 years, 10 females) with unilateral chronic steno-occlusive cerebrovascular disease, without prior knowledge of CCD status. FIELD STRENGTH/SEQUENCE: A 3-T, T1-weighted magnetization-prepared rapid gradient-echo (MPRAGE) and acetazolamide-augmented BOLD imaging performed with a gradient-echo echo-planar imaging (EPI) sequence. ASSESSMENT: A custom denoising pipeline was used to generate BOLD-CVR time signals. CVRend was established using the last minute of the BOLD response relative to the first-minute baseline. Following classification of healthy versus diseased cerebral hemispheres, CVRmax and CVRend were calculated for bilateral cerebral and cerebellar hemispheres. Three independent observers evaluated all data for the presence of CCD. STATISTICAL TESTS: Pearson correlations for comparing CVR across hemispheres, two-proportion Z-tests for comparing CCD prevalence, and Wilcoxon signed-rank tests for comparing median CVR. The level of statistical significance was set at P ≤ 0.05. RESULTS: CCD-related changes were observed on both CVRend and CVRmax maps, with all CCD+ cases identifiable by inspection of either map. Diseased cerebral and contralateral cerebellar hemispheric CVR correlations in CCD+ patients were stronger when using CVRend (r = 0.728) as compared to CVRmax (r = 0.676). CVR correlations between healthy cerebral hemispheres and contralateral cerebellar hemispheres were stronger for CVRmax (r = 0.739) than for CVRend (r = 0.705). DATA CONCLUSION: CCD-related alterations could be observed in CVR examinations. Conventional CVRend may underestimate CVR and could exaggerate CCD. EVIDENCE LEVEL: 4. TECHNICAL EFFICACY: Stage 3.


Asunto(s)
Trastornos Cerebrovasculares , Diásquisis , Femenino , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Circulación Cerebrovascular , Hemodinámica , Imagen por Resonancia Magnética/métodos
20.
J Phys Chem A ; 127(44): 9185-9195, 2023 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-37882654

RESUMEN

The reaction chemistry of 1,1,3,3-tetramethyldisilazane (TMDSZ) in catalytic chemical vapor deposition (Cat-CVD), including its primary decomposition on a heated W filament and secondary gas-phase reactions in a Cat-CVD reactor, was studied using 10.5 eV vacuum ultraviolet single-photon ionization and/or laser-induced electron ionization in tandem with time-of-flight mass spectrometry. It has been demonstrated that TMDSZ initially breaks down to form various species, including methyl radical (•CH3), ammonia (NH3), and 1,1-dimethylsilanimine (DMSA). The activation energies (Ea) for the formation of •CH3 and NH3 were determined to be 61.2 ± 1.0 and 42.1 ± 0.9 kJ mol-1, respectively, in the temperature range of 1400-2000 and 900-2400 °C. It was found that the formation of DMSA may have two different contributing routes, i.e., a concerted one (Ea = 33.6 ± 2.3 kJ mol-1) at lower temperatures of 900-1500 °C and a stepwise one (Ea = 155.0 ± 7.8 kJ mol-1) at higher temperatures of 2100-2400 °C. The secondary gas-phase reactions occurring in the Cat-CVD reactor environment were found to stem from two competing processes. The first one, free-radical short-chain reactions initiated by •CH3 formation and propagated by H abstraction reactions, is the dominating chemical process, producing many high-mass stable alkyl-substituted or silyl-substituted disilazane or trisilazane products via radical recombination reactions. Head-to-tail cycloaddition of unstable DMSA is the second contributing chemical process, which forms cyclodisilazane species. In addition, evidence was found for the conversion of NH3 into H2 and N2 in the Cat-CVD reactor.

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