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1.
Blood ; 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38513233

RESUMO

Thrombophilia is one of the principal features of paroxysmal nocturnal hemoglobinuria (PNH) and constitutes the main cause of disease morbidity/mortality. Anti-complement treatment has revolutionized the natural history of PNH with control of the hemolytic process and abolition of thrombotic events (TE). However, no guidelines exist for the management of thromboembolic complications in this setting, with type and duration of anti-coagulation depending on individual practices. Besides, a scarcity of data is present on the efficacy of direct oral anti-coagulants (DOACs). Herein, we accrued a large real-world cohort of PNH patients from four US centers to explore features, predictors of TE and anti-coagulation strategies. Among 267 patients followed-up for a total of 2043 patient/years, 56 (21%) developed TE. This occurred at disease onset in 43% of cases, involving more frequently the venous system, typically as Budd-Chiari syndrome. Rate of TE was halved in patients receiving complement inhibitors (21 vs 40 TE per 1000 patient/years in untreated cases, with a 2-year cumulative incidence of thrombosis of 3.9% vs 18.3% respectively), and varied according to PNH granulocytes and erythrocytes clone size, type, disease activity parameters, as well as number (>2 mutations or less) and variant allelic frequency of PIGA mutations. Anti-coagulation with warfarin (39%), DOACs (37%), and low-molecular-weight heparin (16%) was administered for a median of 29 months (9-61.8). No thrombotic recurrence was observed in 19 patients treated with DOACs at a median observation of 17.1 months (8.9-45) while 14 cases discontinued anti-coagulation without TE recurrence at a median time of 51.4 months (29.9-86.8).

2.
Hematol Rep ; 16(1): 42-49, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38247995

RESUMO

We report two cases of pancytopenia in patients after recovering from a mild COVID-19, now presenting as paroxysmal nocturnal hemoglobinuria (PNH) and aplastic anemia. These cases illustrate a common pathway whereby a viral trigger causes the clonal expansion of a hematological disorder. Although the association of both cases with COVID-19 is temporal and COVID-19 may be an incidental diagnosis, the growing evidence related to the hematological effects of SARS-CoV-2 infection highlights the need for further investigation into the hematological consequences of COVID-19, particularly in the post-pandemic era.

3.
Nature ; 626(8000): 737-741, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37879361

RESUMO

The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs)1, sources of high-frequency gravitational waves (GWs)2 and likely production sites for heavy-element nucleosynthesis by means of rapid neutron capture (the r-process)3. Here we present observations of the exceptionally bright GRB 230307A. We show that GRB 230307A belongs to the class of long-duration GRBs associated with compact object mergers4-6 and contains a kilonova similar to AT2017gfo, associated with the GW merger GW170817 (refs. 7-12). We obtained James Webb Space Telescope (JWST) mid-infrared imaging and spectroscopy 29 and 61 days after the burst. The spectroscopy shows an emission line at 2.15 microns, which we interpret as tellurium (atomic mass A = 130) and a very red source, emitting most of its light in the mid-infrared owing to the production of lanthanides. These observations demonstrate that nucleosynthesis in GRBs can create r-process elements across a broad atomic mass range and play a central role in heavy-element nucleosynthesis across the Universe.

4.
Nature ; 620(7972): 61-66, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37468630

RESUMO

White dwarfs, the extremely dense remnants left behind by most stars after their death, are characterized by a mass comparable to that of the Sun compressed into the size of an Earth-like planet. In the resulting strong gravity, heavy elements sink towards the centre and the upper layer of the atmosphere contains only the lightest element present, usually hydrogen or helium1,2. Several mechanisms compete with gravitational settling to change a white dwarf's surface composition as it cools3, and the fraction of white dwarfs with helium atmospheres is known to increase by a factor of about 2.5 below a temperature of about 30,000 kelvin4-8; therefore, some white dwarfs that appear to have hydrogen-dominated atmospheres above 30,000 kelvin are bound to transition to be helium-dominated as they cool below it. Here we report observations of ZTF J203349.8+322901.1, a transitioning white dwarf with two faces: one side of its atmosphere is dominated by hydrogen and the other one by helium. This peculiar nature is probably caused by the presence of a small magnetic field, which creates an inhomogeneity in temperature, pressure or mixing strength over the surface9-11. ZTF J203349.8+322901.1 might be the most extreme member of a class of magnetic, transitioning white dwarfs-together with GD 323 (ref. 12), a white dwarf that shows similar but much more subtle variations. This class of white dwarfs could help shed light on the physical mechanisms behind the spectral evolution of white dwarfs.

5.
Clin Lung Cancer ; 24(5): e179-e186, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37217388

RESUMO

BACKGROUND: Historically, limited stage Small Cell Lung Cancer (SCLC) has been treated with concurrent chemoradiation (CRT). While current NCCN guidelines recommend consideration of lobectomy in node-negative cT1-T2 SCLC, data regarding the role of surgery in very limited SCLC is lacking. METHODS: Data from the National VA Cancer Cube were compiled. A total of 1,028 patients with pathologically confirmed stage I SCLC were studied. Only 661 patients that either received surgery or CRT were included. Interval-censored Weibull and Cox proportional hazard regression models were used to estimate median overall survival (OS) and hazard ratio (HR), respectively. Two survival curves were compared by a Wald test. Subset analysis was performed based on the location of the tumor in the upper vs. lower lobe as delineated by ICD-10 codes C34.1 and C34.3. RESULTS: Four-hundred and forty-six patients received concurrent CRT; while 223 underwent treatment that contained surgery (93 surgery only, 87 surgery/chemo, 39 surgery/chemo/radiation and 4 surgery/radiation). The median OS for the surgery-inclusive treatment was 3.87 years (95% CI 3.21-4.48) while median OS for the CRT cohort was 2.45 years (95% CI 2.17-2.74). HR of death for surgery-inclusive treatment when compared to CRT is 0.67 (95% CI 0.55-0.81; P < .001). Subset analysis based on the location of the tumor in both the upper or lower lobes showed improved survival with surgery as compared to CRT regardless of the location. HR for the upper lobe was 0.63 (95% CI 0.50-0.80; P < .001) and lower lobe 0.61 (95% CI 0.42-0.87; P = .006). Multivariable regression analysis accounting for age and ECOG-PS shows a HR 0.60 (95% CI 0.43-0.83; P = .002) favoring surgery. CONCLUSIONS: Surgery was used in less than a third of patients with stage I SCLC who received treatment. Surgery-inclusive multimodality treatment was associated with a longer overall survival as compared to chemoradiation, independent of age, performance status or tumor location. Our study suggests a more expansive role for surgery in stage I SCLC.


Assuntos
Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Carcinoma de Pequenas Células do Pulmão/cirurgia , Neoplasias Pulmonares/cirurgia , Estadiamento de Neoplasias , Quimiorradioterapia , Terapia Combinada
6.
EJHaem ; 4(1): 165-173, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36819163

RESUMO

Several FLT3 inhibitors(i) are available to treat relapsed/refractory (R/R) FLT3-internal tandem duplicated acute myeloid leukemia (AML). This study analyzes the efficacies of various FLT3i (types 1 and 2) tested in clinical trials in treating R/R AML and high-risk myelodysplastic syndromes (HR-MDS). PubMed and EMBASE databases were searched for single/double-arm phase I/II/III R/R AML or HR-MDS clinical trials published between 1/1/2000 and 6/1/2021. The outcomes studied were composite response rate (CRc) and overall response rate (ORR). Toxicities were compared based on the organ system. The 28 studies analyzed had 1927 patients. The pooled ORR and (CRc) for all FLT3i were 53% (95% CI, 43%-63%) and 34% (95% CI, 26%-44%). Pooled ORR and CRc were 37% (95% CI, 25%-51%) and 35% (95% CI, 21%-52%) for type 1 and 58% (95% CI, 43%-71%) and 38% (95% CI, 27%-50%) for type 2, respectively. Gastrointestinal (GI) and hematological toxicity occurred in 22% (95% CI, 19%-25.4%) and 74.6% (95% CI, 70%-79%) with type 1 and 13.9% (95% CI, 12%-16%) and 57.7% (95% CI, 54.6%-60.8%) with type 2 FLT3i. QTc prolongation occurred in 2.06% (95% CI, 1.03%-3.65%) with type 1 and 7% (95% CI, 5.3%-9%) with type 2 FLT3i. Type 2 FLT3i had less GI toxicity but more QTc prolongation. Prospective studies are needed to compare the efficacy of type 1 and 2 FLT3i.

7.
Palliat Med Rep ; 3(1): 279-286, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36479547

RESUMO

Background: With recent improvements in survival of cancer patients and common use of high-value care at end of life, the management of cardiovascular disease (CVD) in patients with cancer is increasingly important. To our knowledge, there are no current U.S. data examining how the presence and extent of cancer influence cardiologists' decision making for common cardiovascular conditions. Methods: An anonymous online vignette-based survey of cardiologists was conducted at five U.S. institutions investigating how the extent of gastrointestinal and thoracic malignancies (prior/localized, metastatic) would influence treatment recommendations for atrial fibrillation (AF), aortic stenosis, unstable angina (UA), and obstructive coronary artery disease (CAD). Results: Thirty-three percent (86/259) of cardiologists completed the survey between September and November 2019. Participants were 67% male, 51% below age 40, and 58% had five or more years of clinical experience. Majority of cardiologists practiced at teaching hospitals (72%) and were noninterventional (63%). Cardiologists were more likely to recommend procedural interventions for patients with localized cancer than for those with metastatic disease: AF (left atrial appendage occlusion: 20% vs. 8%), atrial stenosis (aortic valve repair: 83% vs. 11%), UA (left heart catheter: 70% vs. 27%), and obstructive CAD (percutaneous coronary intervention: 81% vs. 38%). In patients with metastatic cancer, most cardiologists sought an oncology (82%) or a palliative care (69%) consultation. However, a persistent trend of undertreatment in patients with localized cancers and overtreatment in patients with end-of-life disease was apparent. Conclusions: Cardiologists were less likely to recommend invasive cardiovascular therapies to patients with metastatic cancer. This preference pattern likely reflects the influence of comorbidities and quality of life expectation on cardiologists' treatment recommendations but may also be related to the stigma of advanced cancer. Better communication between cardiologists and oncologists is necessary to provide a personalized care of patients with cancer and CVD that would maximize treatment benefit with least morbidity.

8.
Nat Astron ; 3(6): 553-560, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31187071

RESUMO

Cool subdwarfs are metal-poor low-mass stars that formed during the early stages of the evolution of our Galaxy. Because they are relatively rare in the vicinity of the Sun, we know of few cool subdwarfs in the solar neighbourhood, and none with both the mass and the radius accurately determined. This hampers our understanding of stars at the low-mass end of the main-sequence. Here we report the discovery of SDSS J235524.29+044855.7 as an eclipsing binary containing a cool subdwarf star, with a white dwarf companion. From the light-curve and the radial-velocity curve of the binary we determine the mass and the radius of the cool subdwarf and we derive its effective temperature and luminosity by analysing its spectral energy distribution. Our results validate the theoretical mass-radius-effective temperature-luminosity relations for low-mass low-metallicity stars.

9.
Nature ; 533(7603): 366-8, 2016 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-27193683

RESUMO

Interacting compact binary systems provide a natural laboratory in which to study irradiated substellar objects. As the mass-losing secondary (donor) in these systems makes a transition from the stellar to the substellar regime, it is also irradiated by the primary (compact accretor). The internal and external energy fluxes are both expected to be comparable in these objects, providing access to an unexplored irradiation regime. The atmospheric properties of donors are largely unknown, but could be modified by the irradiation. To constrain models of donor atmospheres, it is necessary to obtain accurate observational estimates of their physical properties (masses, radii, temperatures and albedos). Here we report the spectroscopic detection and characterization of an irradiated substellar donor in an accreting white-dwarf binary system. Our near-infrared observations allow us to determine a model-independent mass estimate for the donor of 0.055 ± 0.008 solar masses and an average spectral type of L1 ± 1, supporting both theoretical predictions and model-dependent observational constraints that suggest that the donor is a brown dwarf. Our time-resolved data also allow us to estimate the average irradiation-induced temperature difference between the dayside and nightside of the substellar donor (57 kelvin) and the maximum difference between the hottest and coolest parts of its surface (200 kelvin). The observations are well described by a simple geometric reprocessing model with a bolometric (Bond) albedo of less than 0.54 at the 2σ confidence level, consistent with high reprocessing efficiency, but poor lateral heat redistribution in the atmosphere of the brown-dwarf donor. These results add to our knowledge of binary evolution, in that the donor has survived the transition from the stellar to the substellar regime, and of substellar atmospheres, in that we have been able to test a regime in which the irradiation and the internal energy of a brown dwarf are comparable.

10.
Sci Adv ; 1(9): e1500686, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26601307

RESUMO

The central engines of disc-accreting stellar-mass black holes appear to be scaled down versions of the supermassive black holes that power active galactic nuclei. However, if the physics of accretion is universal, it should also be possible to extend this scaling to other types of accreting systems, irrespective of accretor mass, size, or type. We examine new observations, obtained with Kepler/K2 and ULTRACAM, regarding accreting white dwarfs and young stellar objects. Every object in the sample displays the same linear correlation between the brightness of the source and its amplitude of variability (rms-flux relation) and obeys the same quantitative scaling relation as stellar-mass black holes and active galactic nuclei. We also show that the most important parameter in this scaling relation is the physical size of the accreting object. This establishes the universality of accretion physics from proto-stars still in the star-forming process to the supermassive black holes at the centers of galaxies.

11.
Methods ; 79-80: 47-51, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25171961

RESUMO

Understanding transcriptional regulatory elements and particularly the transcription factor binding sites represents a significant challenge in computational biology. The chromatin immunoprecipitation followed by massive parallel sequencing (ChIP-seq) experiments provide an unprecedented opportunity to study transcription factor binding sites on the genome-wide scale. Here we describe a recently developed tool, SIOMICS, to systematically discover motifs and binding sites of transcription factors and their cofactors from ChIP-seq data. Unlike other tools, SIOMICS explores the co-binding properties of multiple transcription factors in short regions to predict motifs and binding sites. We have previously shown that the original SIOMICS method predicts motifs and binding sites of more cofactors in more accurate and time-effective ways than two popular methods. In this paper, we present the extended SIOMICS method, SIOMICS_Extension, and demonstrate its usage for systematic discovery of cofactor motifs and binding sites. The SIOMICS tool, including SIOMICS and SIOMICS_Extension, are available at http://hulab.ucf.edu/research/projects/SIOMICS/SIOMICS.html.


Assuntos
Imunoprecipitação da Cromatina/métodos , Biologia Computacional/métodos , Elementos Reguladores de Transcrição , Sítios de Ligação , DNA/química , Regulação da Expressão Gênica
12.
Nature ; 498(7455): 463-5, 2013 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-23803845

RESUMO

Low-mass white-dwarf stars are the remnants of disrupted red-giant stars in binary millisecond pulsars and other exotic binary star systems. Some low-mass white dwarfs cool rapidly, whereas others stay bright for millions of years because of stable fusion in thick surface hydrogen layers. This dichotomy is not well understood, so the potential use of low-mass white dwarfs as independent clocks with which to test the spin-down ages of pulsars or as probes of the extreme environments in which low-mass white dwarfs form cannot fully be exploited. Here we report precise mass and radius measurements for the precursor to a low-mass white dwarf. We find that only models in which this disrupted red-giant star has a thick hydrogen envelope can match the strong constraints provided by our data. Very cool low-mass white dwarfs must therefore have lost their thick hydrogen envelopes by irradiation from pulsar companions or by episodes of unstable hydrogen fusion (shell flashes). We also find that this low-mass white-dwarf precursor is a type of pulsating star not hitherto seen. The observed pulsation frequencies are sensitive to internal processes that determine whether this star will undergo shell flashes.

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