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1.
Ann Glob Health ; 90(1): 41, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39005643

RESUMEN

A healthy ocean is essential for human health, and yet the links between the ocean and human health are often overlooked. By providing new medicines, technologies, energy, foods, recreation, and inspiration, the ocean has the potential to enhance human health and wellbeing. However, climate change, pollution, biodiversity loss, and inequity threaten both ocean and human health. Sustainable realisation of the ocean's health benefits will require overcoming these challenges through equitable partnerships, enforcement of laws and treaties, robust monitoring, and use of metrics that assess both the ocean's natural capital and human wellbeing. Achieving this will require an explicit focus on human rights, equity, sustainability, and social justice. In addition to highlighting the potential unique role of the healthcare sector, we offer science-based recommendations to protect both ocean health and human health, and we highlight the unique potential of the healthcare sector tolead this effort.


Asunto(s)
Cambio Climático , Océanos y Mares , Humanos , Biodiversidad , Conservación de los Recursos Naturales , Sector de Atención de Salud , Derechos Humanos , Justicia Social , Desarrollo Sostenible
2.
Chem Mater ; 36(12): 6027-6037, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38947981

RESUMEN

Thermal annealing is the most common postdeposition technique used to crystallize antimony selenide (Sb2Se3) thin films. However, due to slow processing speeds and a high energy cost, it is incompatible with the upscaling and commercialization of Sb2Se3 for future photovoltaics. Herein, for the first time, a fast-annealing technique that uses millisecond light pulses to deliver energy to the sample is adapted to cure thermally evaporated Sb2Se3 films. This study demonstrates how photonic curing (PC) conditions affect the outcome of Sb2Se3 phase conversion from amorphous to crystalline by evaluating the films' crystalline, morphological, and optical properties. We show that Sb2Se3 is readily converted under a variety of different conditions, but the zone where suitable films for optoelectronic applications are obtained is a small region of the parameter space. Sb2Se3 annealing with short pulses (<3 ms) shows significant damage to the sample, while using longer pulses (>5 ms) and a 4-5 J cm-2 radiant energy produces (211)- and (221)-oriented crystalline Sb2Se3 with minimal to no damage to the sample. A proof-of-concept photonically cured Sb2Se3 photovoltaic device is demonstrated. PC is a promising annealing method for large-area, high-throughput annealing of Sb2Se3 with various potential applications in Sb2Se3 photovoltaics.

3.
Laryngoscope Investig Otolaryngol ; 9(4): e1302, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38984073

RESUMEN

Objective: To evaluate the utility of ordering chest x-rays after pediatric tracheostomy tube placement in identifying acute, post-operative complications and how it impacts clinical decision-making. Methods: In this retrospective cohort study, we identified tracheostomies performed in 139 pediatric patients through CPT codes over a 5-year period from 2013 to 2018. Manual chart review was performed for demographic and clinical characteristics, pre-procedure and post-procedure chest x-ray interpretations, and the presence of complications. Each complication was reviewed to see if action was taken due to post-procedure chest x-ray findings. Multivariable logistic regression was performed to determine associations with changes in pre-procedure versus post-procedure chest x-rays. Results: In a cohort of 139 pediatric patients with pre-procedure and post-procedure chest x-rays, 40 (28.8%) of patients had new significant post-procedure chest x-ray findings compared to pre-procedure chest x-ray findings. Of these 40 instances of changes in pre-procedure versus post-procedure chest x-ray findings, only eight resulted in action being taken due to the observed findings. Among these eight instances of action being taken, only one instance involved in invasive action being taken with a bronchoscopy. With multivariable regression analysis, patient age, race, gender, and the presences of genetic syndromes, were not found to be significant risk factors in predicting changes in pre-procedure versus post-procedure chest x-ray. Conclusion: In our study, post-procedure chest x-ray after tracheostomy tube placement did not significantly impact clinical decision making. It may be worth reconsidering the value in routine chest x-rays after tracheostomy tube placement in pediatric patients.

5.
Nat Commun ; 15(1): 4738, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38834625

RESUMEN

Classical photochemistry requires nanosecond excited-state lifetimes for diffusion-controlled reactions. Excited radicals with picosecond lifetimes have been implied by numerous photoredox studies, and controversy has arisen as to whether they can actually be catalytically active. We provide direct evidence for the elusive pre-association between radical ions and substrate molecules, enabling photoinduced electron transfer beyond the diffusion limit. A strategy based on two distinct light absorbers, mimicking the natural photosystems I and II, is used to generate excited radicals, unleashing extreme reduction power and activating C(sp2)-Cl and C(sp2)-F bonds. Our findings provide a long-sought mechanistic understanding for many previous synthetically-oriented works and permit more rational future photoredox reaction development. The newly developed excitation strategy pushes the current limits of reactions based on multi-photon excitation and very short-lived but highly redox active species.

6.
Med Phys ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38922963

RESUMEN

BACKGROUND: Historically, [131I]I has been a common isotope in radionuclide therapy, with [177Lu]Lu-labelled radiopharmaceuticals now seeing a surge in use. These can include no-carrier-added or carrier-added [177Lu]Lu with slight impurities of [177mLu]Lu with a significantly longer half-life than [131I]I. Wastewater from therapy wards can contain a mixture of these radioisotopes. In some countries, national regulations require wastewater to be stored in dedicated systems before it is discharged into the public sewage system. To fulfill legal requirements, the nuclide specific activity concentration must be verified. PURPOSE: We evaluate a method for determining the activity concentration of [177mLu]Lu /[177Lu]Lu at equilibrium and [131I]I in pure and mixed samples in order to prove that the determined values are reliably below the limits for release. METHODS: We analysed the emitted energy spectrum of 1 L samples with a wastewater counter using an energy window-based approach by evaluating measurements from two different time points. Based on the law of decay and the time and energy-dependent measured values, equation systems were set up to calculate the count rates for [131I]I and [177mLu]Lu, which were converted into activity concentration using calibration factors. RESULTS: There is strong linear correlation between the nominal and determined activity concentrations (correlation coefficients R = 0.99; coefficient of determinations R2 = 0.99). We underestimate the actual activity concentration by a median of -1.4% for [177mLu]Lu and overestimate the activity concentration for [131I]I by a median of 7.1%. CONCLUSION: We show that an undercut of the clearance levels for material release is measurable. We analyse and determine activity concentrations of mixed samples consisting of [131I]I and [177mLu]Lu/[177Lu]Lu in equilibrium. The method is simple to implement using a conventional wastewater counter, however with a slightly increased effort, as two samples and measurements are required. The methodology can be adapted for the analysis of other nuclide mixtures.

7.
Nat Immunol ; 25(7): 1257-1269, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38806707

RESUMEN

The circadian clock is a critical regulator of immunity, and this circadian control of immune modulation has an essential function in host defense and tumor immunosurveillance. Here we use a single-cell RNA sequencing approach and a genetic model of colorectal cancer to identify clock-dependent changes to the immune landscape that control the abundance of immunosuppressive cells and consequent suppression of cytotoxic CD8+ T cells. Of these immunosuppressive cell types, PD-L1-expressing myeloid-derived suppressor cells (MDSCs) peak in abundance in a rhythmic manner. Disruption of the epithelial cell clock regulates the secretion of cytokines that promote heightened inflammation, recruitment of neutrophils and the subsequent development of MDSCs. We also show that time-of-day anti-PD-L1 delivery is most effective when synchronized with the abundance of immunosuppressive MDSCs. Collectively, these data indicate that circadian gating of tumor immunosuppression informs the timing and efficacy of immune checkpoint inhibitors.


Asunto(s)
Antígeno B7-H1 , Relojes Circadianos , Inhibidores de Puntos de Control Inmunológico , Células Supresoras de Origen Mieloide , Animales , Ratones , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inhibidores de Puntos de Control Inmunológico/farmacología , Células Supresoras de Origen Mieloide/inmunología , Células Supresoras de Origen Mieloide/metabolismo , Relojes Circadianos/inmunología , Antígeno B7-H1/metabolismo , Antígeno B7-H1/antagonistas & inhibidores , Antígeno B7-H1/inmunología , Ratones Endogámicos C57BL , Ritmo Circadiano/inmunología , Linfocitos T CD8-positivos/inmunología , Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/terapia , Neoplasias Colorrectales/tratamiento farmacológico , Microambiente Tumoral/inmunología , Tolerancia Inmunológica , Humanos , Femenino , Línea Celular Tumoral , Análisis de la Célula Individual , Terapia de Inmunosupresión , Citocinas/metabolismo , Masculino
8.
JCO Precis Oncol ; 8: e2300531, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38723230

RESUMEN

PURPOSE: Conventional surveillance methods are poorly sensitive for monitoring appendiceal cancers (AC). This study investigated the utility of circulating tumor DNA (ctDNA) in evaluating systemic therapy response and recurrence after surgery for AC. METHODS: Patients from two specialized centers who underwent tumor-informed ctDNA testing (Signatera) were evaluated to determine the association between systemic therapy and ctDNA detection. In addition, the accuracy of ctDNA detection during surveillance for the diagnosis of recurrence after complete cytoreductive surgery (CRS) for grade 2-3 ACs with peritoneal metastases (PM) was investigated. RESULTS: In this cohort of 94 patients with AC, most had grade 2-3 tumors (84.0%) and PM (84.0%). Fifty patients completed the assay in the presence of identifiable disease, among which ctDNA was detected in 4 of 7 (57.1%), 10 of 16 (62.5%), and 19 of 27 (70.4%) patients with grade 1, 2, and 3 diseases, respectively. Patients who had recently received systemic chemotherapy had ctDNA detected less frequently (7 of 16 [43.8%] v 26 of 34 [76.5%]; odds ratio, 0.22 [95% CI, 0.06 to 0.82]; P = .02). Among 36 patients with complete CRS for grade 2-3 AC-PM, 16 (44.4%) developed recurrence (median follow-up, 19.6 months). ctDNA detection was associated with shorter recurrence-free survival (median 11.3 months v not reached; hazard ratio, 14.1 [95% CI, 1.7 to 113.8]; P = .01) and showed high accuracy for the detection of recurrence (sensitivity 93.8%, specificity 85.0%). ctDNA was more sensitive than carcinoembryonic antigen (62.5%), CA19-9 (25.0%), and CA125 (18.8%) and was the only elevated biomarker in four (25%) patients with recurrence. CONCLUSION: This study revealed a reduced ctDNA detection frequency after systemic therapy and accurate recurrence assessment after CRS. These findings underscore the role of ctDNA as a predictive and prognostic biomarker for grade 2-3 AC-PM management.


Asunto(s)
Neoplasias del Apéndice , ADN Tumoral Circulante , Humanos , ADN Tumoral Circulante/sangre , ADN Tumoral Circulante/genética , Masculino , Femenino , Neoplasias del Apéndice/genética , Neoplasias del Apéndice/sangre , Neoplasias del Apéndice/patología , Neoplasias del Apéndice/terapia , Neoplasias del Apéndice/tratamiento farmacológico , Persona de Mediana Edad , Anciano , Adulto , Recurrencia Local de Neoplasia/sangre , Anciano de 80 o más Años
9.
J Surg Res ; 299: 343-352, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38795557

RESUMEN

INTRODUCTION: Ovarian metastases from gastrointestinal cancers such as colorectal cancer, also known as Krukenberg tumors (KTs), present unique challenges in management due to diagnostic uncertainty, decreased responsiveness to systemic therapies compared to other sites of metastasis, and associated debilitating symptomatology. Thus, we sought to characterize our institutional outcomes in metastatic colorectal cancer (mCRC) patients with KTs. METHODS: A retrospective single-institution study was performed identifying adult, female patients from 2012 to 2021 with a diagnosis of mCRC. Patient demographics and clinicopathologic characteristics were collected and analyzed. Descriptive statistics, univariate and multivariable analyses, and Kaplan-Meier survival analyses were performed. RESULTS: Of 235 mCRC patients, 45 (19.1%) had KTs, 41 (91.1%) of whom had KTs in conjunction with other metastatic sites. Other initial sites of metastasis included the liver (n = 93, 39.6%), lung (n = 28, 11.9%), and peritoneum (n = 18, 7.7%). In the KT cohort, the median age was 48 y, 53.3% were non-Hispanic White, 100% had microsatellite stable tumors, 33.3% had Kristen Rat Sarcoma Virus (KRAS) mutations, and 6.7% had V-raf Murine Sarcoma Viral Oncogene Homolog B (BRAF) mutations. Fifty five point six percent of KT patients underwent cytoreductive surgery (CRS), 24.4% underwent palliative debulking, and 20% underwent no surgical intervention. Reasons for not undergoing CRS were disease-related (n = 14, 70%), due to poor performance status (n = 1, 5%), or both (n = 5, 25%). Five-year overall survival was 48.2% in KT patients who underwent CRS. Poor tumor grade was an independent predictor of mortality (hazard ratio 10.69, 95% confidence interval 1.20-95.47, P = 0.03). CONCLUSIONS: Almost 90% of our patient cohort with KTs from mCRC experience additional sites of metastasis. Around half of KT patients who underwent CRS were alive at 5 y.


Asunto(s)
Neoplasias Colorrectales , Tumor de Krukenberg , Neoplasias Ováricas , Humanos , Femenino , Persona de Mediana Edad , Estudios Retrospectivos , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/terapia , Tumor de Krukenberg/terapia , Tumor de Krukenberg/mortalidad , Tumor de Krukenberg/diagnóstico , Tumor de Krukenberg/secundario , Adulto , Anciano , Neoplasias Ováricas/mortalidad , Neoplasias Ováricas/terapia , Neoplasias Ováricas/patología , Neoplasias Ováricas/diagnóstico , Estimación de Kaplan-Meier , Resultado del Tratamiento , Procedimientos Quirúrgicos de Citorreducción , Proteínas Proto-Oncogénicas B-raf/genética
10.
Sci Rep ; 14(1): 12239, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38806565

RESUMEN

Laser-driven dynamic compression experiments of plastic materials have found surprisingly fast formation of nanodiamonds (ND) via X-ray probing. This mechanism is relevant for planetary models, but could also open efficient synthesis routes for tailored NDs. We investigate the release mechanics of compressed NDs by molecular dynamics simulation of the isotropic expansion of finite size diamond from different P-T states. Analysing the structural integrity along different release paths via molecular dynamic simulations, we found substantial disintegration rates upon shock release, increasing with the on-Hugnoiot shock temperature. We also find that recrystallization can occur after the expansion and hence during the release, depending on subsequent cooling mechanisms. Our study suggests higher ND recovery rates from off-Hugoniot states, e.g., via double-shocks, due to faster cooling. Laser-driven shock compression experiments of polyethylene terephthalate (PET) samples with in situ X-ray probing at the simulated conditions found diamond signal that persists up to 11 ns after breakout. In the diffraction pattern, we observed peak shifts, which we attribute to thermal expansion of the NDs and thus a total release of pressure, which indicates the stability of the released NDs.

11.
J Am Chem Soc ; 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38598687

RESUMEN

We report a rhenium diimine photosensitizer equipped with a peripheral disulfide unit on one of the bipyridine ligands, [Re(CO)3(bpy)(S-Sbpy4,4)]+ (1+, bpy = 2,2'-bipyridine, S-Sbpy4,4 = [1,2]dithiino[3,4-c:6,5-c']dipyridine), showing anti-Kasha luminescence. Steady-state and ultrafast time-resolved spectroscopies complemented by nonadiabatic dynamics simulations are used to disclose its excited-state dynamics. The calculations show that after intersystem crossing the complex evolves to two different triplet minima: a (S-Sbpy4,4)-ligand-centered excited state (3LC) lying at lower energy and a metal-to-(bpy)-ligand charge transfer (3MLCT) state at higher energy, with relative yields of 90% and 10%, respectively. The 3LC state involves local excitation of the disulfide group into the antibonding σ* orbital, leading to significant elongation of the S-S bond. Intriguingly, it is the higher-lying 3MLCT state, which is assigned to display luminescence with a lifetime of 270 ns: a signature of anti-Kasha behavior. This assignment is consistent with an energy barrier ≥ 0.6 eV or negligible electronic coupling, preventing reaction toward the 3LC state after the population is trapped in the 3MLCT state. This study represents a striking example on how elusive excited-state dynamics of transition-metal photosensitizers can be deciphered by synergistic experiments and state-of-the-art calculations. Disulfide functionalization lays the foundation of a new design strategy toward harnessing excess energy in a system for possible bimolecular electron or energy transfer reactivity.

12.
J Am Chem Soc ; 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38598280

RESUMEN

Substituting precious elements in luminophores and photocatalysts by abundant first-row transition metals remains a significant challenge, and iron continues to be particularly attractive owing to its high natural abundance and low cost. Most iron complexes known to date face severe limitations due to undesirably efficient deactivation of luminescent and photoredox-active excited states. Two new iron(III) complexes with structurally simple chelate ligands enable straightforward tuning of ground and excited state properties, contrasting recent examples, in which chemical modification had a minor impact. Crude samples feature two luminescence bands strongly reminiscent of a recent iron(III) complex, in which this observation was attributed to dual luminescence, but in our case, there is clear-cut evidence that the higher-energy luminescence stems from an impurity and only the red photoluminescence from a doublet ligand-to-metal charge transfer (2LMCT) excited state is genuine. Photoinduced oxidative and reductive electron transfer reactions with methyl viologen and 10-methylphenothiazine occur with nearly diffusion-limited kinetics. Photocatalytic reactions not previously reported for this compound class, in particular the C-H arylation of diazonium salts and the aerobic hydroxylation of boronic acids, were achieved with low-energy red light excitation. Doublet-triplet energy transfer (DTET) from the luminescent 2LMCT state to an anthracene annihilator permits the proof of principle for triplet-triplet annihilation upconversion based on a molecular iron photosensitizer. These findings are relevant for the development of iron complexes featuring photophysical and photochemical properties competitive with noble-metal-based compounds.

13.
Ann Thorac Surg ; 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38663660
14.
J Am Chem Soc ; 146(15): 10418-10431, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38588581

RESUMEN

Light-triggered dissociation of ligands forms the basis for many compounds of interest for photoactivated chemotherapy (PACT), in which medicinally active substances are released or "uncaged" from metal complexes upon illumination. Photoinduced ligand dissociation is usually irreversible, and many recent studies performed in the context of PACT focused on ruthenium(II) polypyridines and related heavy metal complexes. Herein, we report a first-row transition metal complex, in which photoinduced dissociation and spontaneous recoordination of a ligand unit occurs. Two scorpionate-type tridentate chelates provide an overall six-coordinate arylisocyanide environment for chromium(0). Photoexcitation causes decoordination of one of these six ligating units and coordination of a solvent molecule, at least in tetrahydrofuran and 1,4-dioxane solvents, but far less in toluene, and below detection limit in cyclohexane. Transient UV-vis absorption spectroscopy and quantum chemical simulations point to photoinduced ligand dissociation directly from an excited metal-to-ligand charge-transfer state. Owing to the tridentate chelate design and the substitution lability of the first-row transition metal, recoordination of the photodissociated arylisocyanide ligand unit can occur spontaneously on a millisecond time scale. This work provides insight into possible self-healing mechanisms counteracting unwanted photodegradation processes and seems furthermore relevant in the contexts of photoswitching and (photo)chemical information storage.

15.
J Thorac Dis ; 16(3): 1875-1884, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38617767

RESUMEN

Background: Long-standing controversy has existed over whether sublobar resection is an adequate oncological procedure for clinical stage IA non-small cell lung cancer (NSCLC) ≤2 cm, despite the recent randomized trial reports of Japanese Clinical Oncology Group (JCOG) 0802 and Cancer and Leukemia Group B (CALGB) 140503 demonstrating non-inferior outcomes with sublobar resection compared to lobectomy. As practice patterns shift, we sought to compare oncologic outcomes in patients with these early-stage tumors after wedge resection, segmentectomy, or lobectomy in a contemporary, real-world, cohort. Methods: A retrospective review of a prospectively maintained database from a single institution was conducted from 2011 to 2020 to identify all patients with clinically staged IA1 or IA2 NSCLC (tumors ≤2 cm with no nodal involvement). The primary outcomes of interest were overall survival (OS) and disease-free survival (DFS), with secondary outcomes of lung cancer-specific survival (LCSS), recurrence patterns, and perioperative morbidity and mortality. Results: A total of 480 patients were identified; 93 (19.4%) patients underwent wedge resection, 90 (18.7%) received segmentectomy, and 297 (61.9%) underwent lobectomy. Patients who underwent wedge resection had worse Eastern Cooperative Oncology Group (ECOG) performance status (23.7% ECOG 1 or 2 vs. 5.6% among segmentectomy and 5.4% among lobectomy, P<0.05). Both wedge resection and segmentectomy patients had lower preoperative mean percentage of predicted forced expiratory volume in one second (%FEV1) compared to the lobectomy group (81.8% and 82.6% vs. 89.6%, P=0.002), a higher proportion of patients with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD), and a higher Charlson Comorbidity Index. There were no statistically significant differences in 5-year OS, DFS, or LCSS between groups: 90%, 61%, 78% for wedge resections compared with 85%, 75%, 86% for segmentectomy, and 87%, 77%, 87% for lobectomy, respectively. Recurrence was observed in 17 patients who underwent wedge resection (18.3%, 8 local, 9 distant), 12 patients who received segmentectomy (13.4%, 6 local, 6 distant), and 38 patients who underwent lobectomy (12.8%, 11 local, 27 distant), which was not significantly different (P=0.36). Conclusions: Patients with inferior performance status or lower baseline pulmonary function are more likely to receive wedge resection for clinical stage IA NSCLC ≤2 cm in size. For these small tumors, lobectomy, segmentectomy, and wedge resection provide comparable oncologic outcomes.

16.
J Phys Chem B ; 128(17): 4231-4242, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38639329

RESUMEN

Three nonhalogenated ionic liquids (ILs) dissolved in 2-ethylhexyl laurate (2-EHL), a biodegradable oil, are investigated in terms of their bulk and electro-interfacial nanoscale structures using small-angle neutron scattering (SANS) and neutron reflectivity (NR). The ILs share the same trihexyl(tetradecyl)phosphonium ([P6,6,6,14]+) cation paired with different anions, bis(mandelato)borate ([BMB]-), bis(oxalato)borate ([BOB]-), and bis(salicylato)borate ([BScB]-). SANS shows a high aspect ratio tubular self-assembly structure characterized by an IL core of alternating cations and anions with a 2-EHL-rich shell or corona in the bulk, the geometry of which depends upon the anion structure and concentration. NR also reveals a solvent-rich interfacial corona layer. Their electro-responsive behavior, pertaining to the structuring and composition of the interfacial layers, is also influenced by the anion identity. [P6,6,6,14][BOB] exhibits distinct electroresponsiveness to applied potentials, suggesting an ion exchange behavior from cation-dominated to anion-rich. Conversely, [P6,6,6,14][BMB] and [P6,6,6,14][BScB] demonstrate minimal electroresponses across all studied potentials, related to their different dissociative and diffusive behavior. A mixed system is dominated by the least soluble IL but exhibits an increase in disorder. This work reveals the subtlety of anion architecture in tuning bulk and electro-interfacial properties, offering valuable molecular insights for deploying nonhalogenated ILs as additives in biodegradable lubricants and supercapacitors.

17.
Nat Plants ; 10(5): 749-759, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38641663

RESUMEN

Epigenetic gene silencing induced by expanded repeats can cause diverse phenotypes ranging from severe growth defects in plants to genetic diseases such as Friedreich's ataxia in humans. The molecular mechanisms underlying repeat expansion-induced epigenetic silencing remain largely unknown. Using a plant model with a temperature-sensitive phenotype, we have previously shown that expanded repeats can induce small RNAs, which in turn can lead to epigenetic silencing through the RNA-dependent DNA methylation pathway. Here, using a genetic suppressor screen and yeast two-hybrid assays, we identified novel components required for epigenetic silencing caused by expanded repeats. We show that FOURTH ULP GENE CLASS 1 (FUG1)-an uncharacterized SUMO protease with no known role in gene silencing-is required for epigenetic silencing caused by expanded repeats. In addition, we demonstrate that FUG1 physically interacts with ALFIN-LIKE 3 (AL3)-a histone reader that is known to bind to active histone mark H3K4me2/3. Loss of function of AL3 abolishes epigenetic silencing caused by expanded repeats. AL3 physically interacts with the chromodomain protein LIKE HETEROCHROMATIN 1 (LHP1)-known to be associated with the spread of the repressive histone mark H3K27me3 to cause repeat expansion-induced epigenetic silencing. Loss of any of these components suppresses repeat expansion-associated phenotypes coupled with an increase in IIL1 expression with the reversal of gene silencing and associated change in epigenetic marks. Our findings suggest that the FUG1-AL3-LHP1 module is essential to confer repeat expansion-associated epigenetic silencing and highlight the importance of post-translational modifiers and histone readers in epigenetic silencing.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Silenciador del Gen , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Expansión de las Repeticiones de ADN/genética , Epigénesis Genética , Regulación de la Expresión Génica de las Plantas , Histonas/metabolismo , Histonas/genética
18.
Nat Chem ; 16(7): 1151-1159, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38499849

RESUMEN

Photoredox catalysis relies on light-induced electron transfer leading to a radical pair comprising an oxidized donor and a reduced acceptor in a solvent cage. For productive onward reaction to occur, the oxidized donor and the reduced acceptor must escape from that solvent cage before they undergo spontaneous reverse electron transfer. Here we show the decisive role that cage escape plays in three benchmark photocatalytic reactions, namely, an aerobic hydroxylation, a reductive debromination and an aza-Henry reaction. Using ruthenium(II)- and chromium(III)-based photocatalysts, which provide inherently different cage escape quantum yields, we determined quantitative correlations between the rates of photoredox product formation and the cage escape quantum yields. These findings can be largely rationalized within the framework of Marcus theory for electron transfer.

19.
EJNMMI Radiopharm Chem ; 9(1): 26, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38551764

RESUMEN

BACKGROUND: To investigate the capacity of 99mTc-labeled 1-thio-ß-D-glucose (1-TG) and 5-thio-D-glucose (5-TG) to act as a marker for glucose consumption in tumor cells in vivo as well as to evaluate the biodistribution of 1-TG and 5-TG. We investigated the biodistribution, including tumor uptake, of 1-TG and 5-TG at various time points after injection (0.5, 2 and 4 h) in human colorectal carcinoma (HCT-116) and human lung adenocarcinoma (A549) xenograft bearing nude mice (N = 4 per tracer and time point). RESULTS: Ex vivo biodistribution studies revealed a moderate uptake with a maximum tumor-to-muscle ratio of 4.22 ± 2.7 and 2.2 ± 1.3 (HCT-116) and of 3.2 ± 1.1 and 4.1 ± 1.3 (A549) for 1-TG and 5-TG, respectively, with a peak at 4 h for 1-TG and 5-TG. Biodistribution revealed a significantly higher uptake compared to blood in kidneys (12.18 ± 8.77 and 12.69 ± 8.93%ID/g at 30 min) and liver (2.6 ± 2.8%ID/g) for 1-TG and in the lung (7.24 ± 4.1%ID/g), liver (6.38 ± 2.94%ID/g), and kidneys (4.71 ± 1.97 and 4.81 ± 1.91%ID/g) for 5-TG. CONCLUSIONS: 1-TG and 5-TG showed an insufficient tumor uptake with a moderate tumor-to-muscle ratio, not reaching the levels of commonly used tracer, for diagnostic use in human colorectal carcinoma and human lung adenocarcinoma xenograft model.

20.
Support Care Cancer ; 32(3): 206, 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38433169

RESUMEN

BACKGROUND: Malignant bowel obstruction (MBO) affects 3% to 15% of all cancer patients. In patients with advanced cancer and inoperable MBO, the average survival varies between four to nine weeks. Parenteral nutrition (PN) may improve survival in specific patient populations with malignant bowel obstruction. AIMS: This retrospective, single-center cohort study aimed to review individual patient outcomes on PN in the setting of advanced cancer with a diagnosis of MBO and identify clinical and laboratory markers predictive of short- and long-term survival to further highlight patients that would benefit from PN in the setting of an inoperable MBO. RESULTS: In a retrospective analysis of 68 patients receiving PN for inoperable MBO, the median survival was 142 (IQR: 63.3-239.5) days. Patients experienced a median number of two hospital readmissions (range: 0-10) and spent a median of 29 days (range: 0-105) in the hospital after starting PN. Eighteen (26.5%) patients developed a catheter-related bloodstream infection (CRBSI). A diagnosis of appendiceal cancer was identified as a predictive marker of improved survival (HR: 0.53, 95% CI: 0.29-0.92, p = 0.023). CONCLUSIONS: The use of PN in the context of end-of-life cancer care is a practice that necessitates improvement. Recognizing the outcomes and patient experiences of PN utilization is essential to physicians and patients.


Asunto(s)
Neoplasias , Humanos , Estudios de Cohortes , Estudios Retrospectivos , Neoplasias/complicaciones , Neoplasias/terapia , Hospitales , Nutrición Parenteral
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