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1.
Nature ; 626(7999): 500-504, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38356071

RESUMEN

Magnetars are neutron stars with extremely high magnetic fields (≳1014 gauss) that exhibit various X-ray phenomena such as sporadic subsecond bursts, long-term persistent flux enhancements and variable rotation-period derivative1,2. In 2020, a fast radio burst (FRB), akin to cosmological millisecond-duration radio bursts, was detected from the Galactic magnetar SGR 1935+2154 (refs. 3-5), confirming the long-suspected association between some FRBs and magnetars. However, the mechanism for FRB generation in magnetars remains unclear. Here we report the X-ray observation of two glitches in SGR 1935+2154 within a time interval of approximately nine hours, bracketing an FRB that occurred on 14 October 20226,7. Each glitch involved a significant increase in the magnetar's spin frequency, being among the largest abrupt changes in neutron-star rotation8-10 observed so far. Between the glitches, the magnetar exhibited a rapid spin-down phase, accompanied by an increase and subsequent decline in its persistent X-ray emission and burst rate. We postulate that a strong, ephemeral, magnetospheric wind11 provides the torque that rapidly slows the star's rotation. The trigger for the first glitch couples the star's crust to its magnetosphere, enhances the various X-ray signals and spawns the wind that alters magnetospheric conditions that might produce the FRB.

2.
Cancer Treat Res ; 184: 61-73, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36449188

RESUMEN

Translating research findings into policy is important. Health policy researchers often testify before Congressional subcommittees and provide background on health policy issues. A rarely used, but important, tool for facilitating translation of research into policy is via filing a Citizen Petition.


Asunto(s)
Política de Salud , Estados Unidos , Humanos , United States Food and Drug Administration
3.
Cancer Treat Res ; 184: 113-127, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36449192

RESUMEN

Logistic regression is a statistical tool of paramount significance in the field of epidemiology1 and ranks as one of the most frequently published multivariable analyses for designs involving a single binary dependent variable and one or more independent variables in the fields of public health2,3 and medical4 research.


Asunto(s)
Aprendizaje Automático , Humanos
4.
Oncologist ; 26(8): e1418-e1426, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33586299

RESUMEN

Biosimilars are biologic drug products that are highly similar to reference products in analytic features, pharmacokinetics and pharmacodynamics, immunogenicity, safety, and efficacy. Biosimilar epoetin received Food and Drug Administration (FDA) approval in 2018. The manufacturer received an FDA nonapproval letter in 2017, despite receiving a favorable review by FDA's Oncologic Drugs Advisory Committee (ODAC) and an FDA nonapproval letter in 2015 for an earlier formulation. We discuss the 2018 FDA approval, the 2017 FDA ODAC Committee review, and the FDA complete response letters in 2015 and 2017; review concepts of litigation, naming, labeling, substitution, interchangeability, and pharmacovigilance; review European and U.S. oncology experiences with biosimilar epoetin; and review the safety of erythropoiesis-stimulating agents. In 2020, policy statements from AETNA, United Health Care, and Humana indicated that new epoetin oncology starts must be for biosimilar epoetin unless medical need for other epoetins is documented. Empirical studies report that as of 2012, reference epoetin use decreased from 40%-60% of all patients with cancer with chemotherapy-induced anemia to <5% of such patients because of safety concerns. Between 2018 and 2020, biosimilar epoetin use varied, increasing to 81% among one private insurer's patients covered by Medicare whose cancer care is administered with Oncology Analytics and to 41% with the same private insurer's patients with cancer covered by commercial health insurance and administered by the private insurer, to 0% in several Veterans Administration Hospitals, increasing to 100% in one large county hospital in California, and with yet-to-be-reported data from most oncology settings. We conclude that biosimilar epoetin appears to have overcome some barriers since 2015, although current uptake in the U.S. is variable. Pricing and safety considerations for all erythropoiesis-stimulating agents are primary determinants of biosimilar epoetin oncology uptake. IMPLICATIONS FOR PRACTICE: Few oncologists understand substitution and interchangeability of biosimilars with reference drugs. Epoetin biosimilar is new to the market, and physician and patient understanding is limited. The development of epoetin biosimilar is not familiar to oncologists.


Asunto(s)
Anemia , Antineoplásicos , Biosimilares Farmacéuticos , Neoplasias , Anciano , Anemia/inducido químicamente , Anemia/tratamiento farmacológico , Antineoplásicos/efectos adversos , Biosimilares Farmacéuticos/efectos adversos , Epoetina alfa/uso terapéutico , Humanos , Medicare , Neoplasias/complicaciones , Neoplasias/tratamiento farmacológico , Estados Unidos
5.
Phys Rev Lett ; 127(25): 251302, 2021 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-35029450

RESUMEN

We search for a first-order phase transition gravitational wave signal in 45 pulsars from the NANOGrav 12.5-year dataset. We find that the data can be modeled in terms of a strong first order phase transition taking place at temperatures below the electroweak scale. However, we do not observe any strong preference for a phase-transition interpretation of the signal over the standard astrophysical interpretation in terms of supermassive black hole mergers; but we expect to gain additional discriminating power with future datasets, improving the signal to noise ratio and extending the sensitivity window to lower frequencies. An interesting open question is how well gravitational wave observatories could separate such signals.

6.
Lancet Oncol ; 21(12): e575-e588, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33271114

RESUMEN

The EU, the USA, and Japan account for the majority of biological pharmacotherapy use worldwide. Biosimilar regulatory approval pathways were authorised in the EU (2006), in Japan (2009), and in the USA (2015), to facilitate approval of biological drugs that are highly similar to reference products and to encourage market competition. Between 2007 and 2020, 33 biosimilars for oncology were approved by the European Medicines Agency (EMA), 16 by the US Food and Drug Administration (FDA), and ten by the Japan Pharmaceuticals and Medical Devices Agency (PMDA). Some of these approved applications were initially rejected because of manufacturing concerns (four of 36 [11%] with the EMA, seven of 16 [44%] with the FDA, none of ten for the PMDA). Median times from initial regulatory submission before approval of oncology biosimilars were 1·5 years (EMA), 1·3 years (FDA), and 0·9 years (PMDA). Pharmacists can substitute biosimilars for reference biologics in some EU countries, but not in the USA or Japan. US regulation prohibits substitution, unless the biosimilar has been approved as interchangeable, a designation not yet achieved for any biosimilar in the USA. Japan does not permit biosimilar substitution, as prescribers must include the product name on each prescription and that specific product must be given to the patient. Policy Reviews published in 2014 and 2016 in The Lancet Oncology focused on premarket and postmarket policies for oncology biosimilars before most of these drugs received regulatory approval. In this Policy Review from the Southern Network on Adverse Reactions, we identify factors preventing the effective launch of oncology biosimilars. Introduction to the market has been more challenging with therapeutic than for supportive care oncology biosimilars. Addressing region-specific competition barriers and educational needs would improve the regulatory approval process and market launches for these biologics, therefore expanding patient access to these products in the EU, the USA, and Japan.


Asunto(s)
Antineoplásicos Inmunológicos/uso terapéutico , Biosimilares Farmacéuticos/uso terapéutico , Aprobación de Drogas , Hematínicos/uso terapéutico , Neoplasias/tratamiento farmacológico , United States Food and Drug Administration , Antineoplásicos Inmunológicos/efectos adversos , Bevacizumab/uso terapéutico , Biosimilares Farmacéuticos/efectos adversos , Aprobación de Drogas/legislación & jurisprudencia , Sustitución de Medicamentos , Eritropoyetina/análogos & derivados , Eritropoyetina/uso terapéutico , Europa (Continente) , Filgrastim/uso terapéutico , Hematínicos/efectos adversos , Humanos , Japón , Neoplasias/inmunología , Neoplasias/mortalidad , Seguridad del Paciente , Formulación de Políticas , Polietilenglicoles/uso terapéutico , Medición de Riesgo , Rituximab/uso terapéutico , Trastuzumab/uso terapéutico , Resultado del Tratamiento , Estados Unidos , United States Food and Drug Administration/legislación & jurisprudencia
7.
Oncologist ; 24(4): 537-548, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30842244

RESUMEN

Biosimilar filgrastims are primarily indicated for chemotherapy-induced neutropenia prevention. They are less expensive formulations of branded filgrastim, and biosimilar filgrastim was the first biosimilar oncology drug administered in European Union (EU) countries, Japan, and the U.S. Fourteen biosimilar filgrastims have been marketed in EU countries, Japan, the U.S., and Canada since 2008, 2012, 2015, and 2016, respectively. We reviewed experiences and policies for biosimilar filgrastim markets in EU countries and Japan, where uptake has been rapid, and in the U.S. and Canada, where experience is rapidly emerging. U.S. regulations for designating biosimilar interchangeability are under development, and such regulations have not been developed in most other countries. Pharmaceutical substitution is allowed for new filgrastim starts in some EU countries and in Canada, but not Japan and the U.S. In EU countries, biosimilar adoption is facilitated with favorable hospital tender offers. U.S. adoption is reportedly 24%, while the second filgrastim biosimilar is priced 30% lower than branded filgrastim and 20% lower than the first biosimilar filgrastim approved by the U.S. Food and Drug Administration. Utilization is about 60% in EU countries, where biosimilar filgrastim is marketed at a 30%-40% discount. In Japan, biosimilar filgrastim utilization is 45%, primarily because of 35% discounts negotiated by Central Insurance and hospital-only markets. Overall, biosimilar filgrastim adoption barriers are small in many EU countries and Japan and are diminishing in Canada in the U.S. Policies facilitating improved U.S. adoption of biosimilar filgrastim, based on positive experiences in EU countries and Japan, including favorable insurance coverage; larger price discount relative to reference filgrastim pricing; closing of the "rebate trap" with transparent pricing information; formal educational efforts of patients, physicians, caregivers, and providers; and allowance of pharmaceutical substitution of biosimilar versus reference filgrastim, should be considered. IMPLICATIONS FOR PRACTICE: We reviewed experiences and policies for biosimilar filgrastims in Europe, Japan, Canada, and the U.S. Postmarketing harmonization of regulatory policies for biosimilar filgrastims has not occurred. Acceptance of biosimilar filgrastims for branded filgrastim, increasing in the U.S. and in Canada, is commonplace in Japan and Europe. In the U.S., some factors, accepted in Europe or Japan, could improve uptake, including acceptance of biosimilars as safe and effective; larger cost savings, decreasing "rebate traps" where pharmaceutical benefit managers support branded filgrastim, decreased use of patent litigation/challenges, and allowing pharmacists to routinely substitute biosimilar for branded filgrastim.


Asunto(s)
Antineoplásicos/efectos adversos , Biosimilares Farmacéuticos/uso terapéutico , Ahorro de Costo/estadística & datos numéricos , Costos de los Medicamentos/legislación & jurisprudencia , Industria Farmacéutica/legislación & jurisprudencia , Filgrastim/uso terapéutico , Neutropenia/tratamiento farmacológico , Biosimilares Farmacéuticos/economía , Canadá/epidemiología , Europa (Continente)/epidemiología , Filgrastim/economía , Fármacos Hematológicos/economía , Fármacos Hematológicos/uso terapéutico , Humanos , Incidencia , Japón/epidemiología , Neoplasias/tratamiento farmacológico , Neutropenia/inducido químicamente , Neutropenia/epidemiología , Estados Unidos/epidemiología , United States Food and Drug Administration
8.
Biochim Biophys Acta ; 1849(10): 1277-88, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26291278

RESUMEN

Expression of the antioxidant gene heme oxygenase-1 (HO-1) is primarily induced through NF-E2-related factor 2 (Nrf2)-mediated activation of the antioxidant response element (ARE). Gene transcription is coordinately regulated by transcription factor activity at enhancer elements and epigenetic alterations such as the posttranslational modification of histone proteins. However, the role of histone modifications in the Nrf2-ARE axis remains largely uncharacterized. The environmental contaminant arsenite is a potent inducer of both HO-1 expression and phosphorylation of histone H3 serine 10 (H3S10); therefore, we investigated the relationships between Nrf2 and H3S10 phosphorylation in arsenite-induced, ARE-dependent, transcriptional activation of the human HO-1 gene. Arsenite increased phosphorylation of H3S10 both globally and at the HO-1 promoter concomitantly with HO-1 transcription in human HaCaT keratinocytes. Conversely, arsenite-induced H3S10 phosphorylation and HO-1 expression were blocked by N-acetylcysteine (NAC), the c-Jun N-terminal kinase (JNK) inhibitor SP600125, and JNK knockdown (siJNK). Interestingly, ablation of arsenite-induced H3S10 phosphorylation by SP600125 or siJNK did not inhibit Nrf2 nuclear accumulation nor ARE binding, despite inhibiting HO-1 expression. In response to arsenite, binding of Nrf2 to the HO-1 ARE preceded phosphorylation of H3S10 at the HO-1 ARE. Furthermore, arsenite-mediated occupancy of phosphorylated H3S10 at the HO-1 ARE was decreased in Nrf2-deficient mouse embryonic fibroblasts. These results suggest the involvement of H3S10 phosphorylation in the Nrf2-ARE axis by proposing that Nrf2 may influence H3S10 phosphorylation at the HO-1 ARE and additional promoter regions. Our data highlights the complex interplay between Nrf2 and H3S10 phosphorylation in arsenite-activated HO-1 transcription.


Asunto(s)
Elementos de Respuesta Antioxidante/genética , Hemo-Oxigenasa 1/biosíntesis , Histonas/genética , Factor 2 Relacionado con NF-E2/genética , Activación Transcripcional/genética , Animales , Arsenitos/farmacología , Regulación Enzimológica de la Expresión Génica , Hemo-Oxigenasa 1/genética , Hemo-Oxigenasa 1/metabolismo , Histonas/metabolismo , Humanos , Queratinocitos/metabolismo , Ratones , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo/genética , Fosforilación , Regiones Promotoras Genéticas , Unión Proteica , Transducción de Señal , Activación Transcripcional/efectos de los fármacos
9.
Toxicol Appl Pharmacol ; 289(3): 534-41, 2015 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-26472158

RESUMEN

Exposure to elevated levels of the toxic metals inorganic arsenic (iAs) and cadmium (Cd) represents a major global health problem. These metals often occur as mixtures in the environment, creating the potential for interactive or synergistic biological effects different from those observed in single exposure conditions. In the present study, environmental mixtures collected from two waste sites in China and comparable mixtures prepared in the laboratory were tested for toxicogenomic response in placental JEG-3 cells. These cells serve as a model for evaluating cellular responses to exposures during pregnancy. One of the mixtures was predominated by iAs and one by Cd. Six gene biomarkers were measured in order to evaluate the effects from the metal mixtures using dose and time-course experiments including: heme oxygenase 1 (HO-1) and metallothionein isoforms (MT1A, MT1F and MT1G) previously shown to be preferentially induced by exposure to either iAs or Cd, and metal transporter genes aquaporin-9 (AQP9) and ATPase, Cu(2+) transporting, beta polypeptide (ATP7B). There was a significant increase in the mRNA expression levels of ATP7B, HO-1, MT1A, MT1F, and MT1G in mixture-treated cells compared to the iAs or Cd only-treated cells. Notably, the genomic responses were observed at concentrations significantly lower than levels found at the environmental collection sites. These data demonstrate that metal mixtures increase the expression of gene biomarkers in placental JEG-3 cells in a synergistic manner. Taken together, the data suggest that toxic metals that co-occur may induce detrimental health effects that are currently underestimated when analyzed as single metals.


Asunto(s)
Intoxicación por Metales Pesados , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/genética , Placenta/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Arsénico/toxicidad , Cadmio/toxicidad , Línea Celular Tumoral , China , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Metalotioneína/metabolismo , Metales Pesados/toxicidad , Placenta/metabolismo , Intoxicación , Embarazo
10.
Chem Res Toxicol ; 28(6): 1144-55, 2015 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-26039340

RESUMEN

There is strong epidemiologic evidence linking chronic exposure to inorganic arsenic (iAs) to myriad adverse health effects, including cancer of the bladder. We set out to identify DNA methylation patterns associated with arsenic and its metabolites in exfoliated urothelial cells (EUCs) that originate primarily from the urinary bladder, one of the targets of arsenic-induced carcinogenesis. Genome-wide, gene-specific promoter DNA methylation levels were assessed in EUCs from 46 residents of Chihuahua, Mexico, and the relationship was examined between promoter methylation profiles and the intracellular concentrations of total arsenic and arsenic species. A set of 49 differentially methylated genes was identified with increased promoter methylation associated with EUC tAs, iAs, and/or monomethylated As (MMAs) enriched for their roles in metabolic disease and cancer. Notably, no genes had differential methylation associated with EUC dimethylated As (DMAs), suggesting that DMAs may influence DNA methylation-mediated urothelial cell responses to a lesser extent than iAs or MMAs. Further analysis showed that 22 of the 49 arsenic-associated genes (45%) are also differentially methylated in bladder cancer tissue identified using The Cancer Genome Atlas repository. Both the arsenic- and cancer-associated genes are enriched for the binding sites of common transcription factors known to play roles in carcinogenesis, demonstrating a novel potential mechanistic link between iAs exposure and bladder cancer.


Asunto(s)
Arsénico/toxicidad , Metilación de ADN/efectos de los fármacos , Neoplasias de la Vejiga Urinaria/inducido químicamente , Neoplasias de la Vejiga Urinaria/genética , Urotelio/citología , Urotelio/efectos de los fármacos , Adulto , Anciano , Arsénico/metabolismo , Transformación Celular Neoplásica/inducido químicamente , Metilación de ADN/genética , Femenino , Humanos , Persona de Mediana Edad , Neoplasias de la Vejiga Urinaria/patología , Adulto Joven
11.
Lancet Oncol ; 15(13): e594-e605, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25456378

RESUMEN

Biological oncology products are integral to cancer treatment, but their high costs pose challenges to patients, families, providers, and insurers. The introduction of biosimilar agents-molecules that are similar in structure, function, activity, immunogenicity, and safety to the original biological drugs-provide opportunities both to improve health-care access and outcomes, and to reduce costs. Several international regulatory pathways have been developed to expedite entry of biosimilars into global marketplaces. The first wave of oncology biosimilar use was in Europe and India in 2007. Oncology biosimilars are now widely marketed in several countries in Europe, and in Australia, Japan, China, Russia, India, and South Korea. Their use is emerging worldwide, with the notable exception of the USA, where several regulatory and cost barriers to biosimilar approval exist. In this Review, we discuss oncology biosimilars and summarise their regulatory frameworks, clinical experiences, and safety concerns.


Asunto(s)
Antineoplásicos/uso terapéutico , Biosimilares Farmacéuticos/normas , Biosimilares Farmacéuticos/uso terapéutico , Aprobación de Drogas/legislación & jurisprudencia , Neoplasias/tratamiento farmacológico , Humanos
12.
FASEB J ; 27(9): 3763-74, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23699174

RESUMEN

Antioxidant genes such as ferritin are transcriptionally activated in oxidative stress via the antioxidant responsive element (ARE), to which nuclear factor-E2-related factor 2 (Nrf2) binds and activates transcription. Histone modification plays a cooperative and essential role in transcriptional regulation; however, its role in antioxidant gene transcription remains elusive. Arsenic exposure activated ferritin transcription via the ARE concomitant with increased methylation of histones H4Arg3 (H4R3) and H3Arg17 (H3R17). To test our hypothesis that histone H4R3 and H3R17 methylation regulates ferritin transcription, H4R3 and H3R17 protein arginine (R) methyltransferases 1 and 4 (PRMT1 and PRMT4) were investigated. Arsenic exposure of human HaCaT keratinocytes induced nuclear accumulation of PRMT1 and PRMT4, histone H4R3 and H3R17 methylation proximal to the ARE, but not to the non-ARE regions of ferritin genes. PRMT1 or PRMT4 knockdown did not block Nrf2 nuclear accumulation but inhibited Nrf2 binding to the AREs by ∼40% (P<0.05), thus diminishing ferritin transcription in HaCaT and human primary keratinocytes and fibroblasts, causing enhanced cellular susceptibility to arsenic toxicity as evidenced by 2-fold caspase 3 activation. Focused microarray further characterized several oxidative stress response genes are subject to PRMT1 or PRMT4 regulation. Collectively, PRMT1 and PRMT4 regulate the ARE and cellular antioxidant response to arsenic.


Asunto(s)
Ferritinas/genética , Factor 2 Relacionado con NF-E2/metabolismo , Proteína-Arginina N-Metiltransferasas/metabolismo , Proteínas Represoras/metabolismo , Antioxidantes/metabolismo , Arsénico/toxicidad , Línea Celular , Células Cultivadas , Fibroblastos/citología , Fibroblastos/metabolismo , Histonas/metabolismo , Humanos , Queratinocitos/citología , Queratinocitos/metabolismo , Metilación , Factor 2 Relacionado con NF-E2/genética , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/genética , Proteína-Arginina N-Metiltransferasas/genética , Proteínas Represoras/genética , Transcripción Genética/efectos de los fármacos , Transcripción Genética/genética
13.
Biochemistry ; 52(30): 5075-83, 2013 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-23829535

RESUMEN

Resveratrol, a natural polyphenol, increases cellular antioxidant capacity by inducing the expression of a battery of cytoprotective genes through an antioxidant responsive element (ARE). However, upstream signaling events initiated by resveratrol leading to the activation of an ARE enhancer, particularly in immune cells, have not been fully elucidated. In this study, ARE-dependent transcriptional activation of the ferritin heavy chain (ferritin H) gene by resveratrol was further investigated in Jurkat T cells and human peripheral blood mononuclear cells. We found that AMP-activated protein kinase (AMPK) plays a key role in the activation of nuclear factor E2-related factor (Nrf2) and subsequent ARE-dependent ferritin H gene transcription by resveratrol. A chromatin immunoprecipitation assay for Nrf2 after AMPKα knockdown with siRNA revealed that Nrf2 nuclear accumulation and subsequent binding to the ferritin H ARE induced by resveratrol were dependent on activation of AMPKα, but not PI3K/AKT. Furthermore, AMPKα knockdown blocked resveratrol-induced phosphorylation of glycogen synthase kinase 3ß (GSK3ß) at Ser9 as well as ARE-dependent transcriptional activation of the ferritin H and HO-1 genes, suggesting that AMPKα is an upstream kinase for GSK3ß phosphorylation and activation of the Nrf2-ARE pathway. Consistently, GSK3ß knockdown by siRNA enhanced resveratrol-mediated ferritin H mRNA induction, and the inhibition of AMPKα by compound C or siRNA weakened the protective effect of resveratrol against oxidative stress-induced cytotoxicity in CD3+ T cells. Collectively, these results suggest that AMPKα plays a significant role in ARE-dependent transcription of ferritin H genes by resveratrol and may influence the redox status in immune cells.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Antioxidantes/farmacología , Apoferritinas/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Estilbenos/farmacología , Linfocitos T/efectos de los fármacos , Proteínas Quinasas Activadas por AMP/antagonistas & inhibidores , Proteínas Quinasas Activadas por AMP/química , Proteínas Quinasas Activadas por AMP/genética , Antioxidantes/química , Apoferritinas/genética , Activación Enzimática/efectos de los fármacos , Glucógeno Sintasa Quinasa 3/antagonistas & inhibidores , Glucógeno Sintasa Quinasa 3/genética , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Humanos , Células Jurkat , Células K562 , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo/efectos de los fármacos , Fosforilación/efectos de los fármacos , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Interferencia de ARN , Elementos de Respuesta/efectos de los fármacos , Resveratrol , Serina/metabolismo , Estilbenos/antagonistas & inhibidores , Linfocitos T/metabolismo
14.
J Gen Intern Med ; 27(12): 1697-703, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22692632

RESUMEN

Identification of serious adverse drug reactions (sADRS) associated with commonly used drugs can elude detection for years. Reye's syndrome (RS), nephrogenic systemic fibrosis (NSF), and pure red cell aplasia (PRCA) among chronic kidney disease (CKD) patients were recognized in 1951, 2000, and 1998, respectively. Reports associating these syndromes with aspirin, gadodiamide, and epoetin, were published 29, 6, and 4 years later, respectively. We obtained primary information from clinicians who identified causes of these sADRs and reviewed factors contributing to delayed identification of these toxicities. Overall, 3,500 aspirin-associated RS cases in the United States, 1,605 gadolinium-associated NSF cases, and 181 epoetin-associated PRCA cases were reported. Delays in FDA regulation of over-the- counter medications and administration of aspirin to children contributed to development of RS. For NSF, in 1996, the Danish Medicine Agency approved high-dose gadodiamide administration to chronic kidney disease (CKD) patients undergoing MR scans. Overall, 88 % of Danish NSF cases were from two hospitals and 97 % of United States' NSF cases were from 60 hospitals. These hospitals frequently administered high-doses of gadodiamide to CKD patients. Another factor was the decision to administer linear chelated contrast agents versus lower risk macrocyclic chelated agents. For PRCA, increased use of subcutaneous epoetin formulations to CKD patients, in part due to convenience and cost-savings considerations, and a European regulatory requirement requiring removal of albumin as a stabilizer, led to toxicity. Overall, 81, 13, and 17 years elapsed between drug introduction into practice and identification of a causal relationship for aspirin, erythropoietin, and gadodiamide, respectively. A substantial decline in new cases of these sADRs occurred within two years of identification of the offending drug. Clinicians should be vigilant for sADRs, even for frequently-prescribed pharmaceuticals, particularly in settings where formulation or regulatory changes have occurred, or when over-the-counter, off-label, or pediatric use is common.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/inducido químicamente , Dermopatía Fibrosante Nefrogénica/inducido químicamente , Aplasia Pura de Células Rojas/inducido químicamente , Síndrome de Reye/inducido químicamente , Aspirina/efectos adversos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/fisiopatología , Eritropoyetina/efectos adversos , Femenino , Gadolinio/efectos adversos , Humanos , Masculino , Dermopatía Fibrosante Nefrogénica/epidemiología , Dermopatía Fibrosante Nefrogénica/fisiopatología , Prevalencia , Pronóstico , Aplasia Pura de Células Rojas/epidemiología , Aplasia Pura de Células Rojas/fisiopatología , Síndrome de Reye/epidemiología , Síndrome de Reye/fisiopatología , Medición de Riesgo , South Carolina , Tasa de Supervivencia
15.
Nature ; 434(7029): 50-2, 2005 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-15744294

RESUMEN

Transient astronomical sources are typically powered by compact objects and usually signify highly explosive or dynamic events. Although high-time-resolution observations are often possible in radio astronomy, they are usually limited to quite narrow fields of view. The dynamic radio sky is therefore poorly sampled, in contrast to the situation in the X-ray and gamma-ray bands in which wide-field instruments routinely detect transient sources. Here we report a transient radio source, GCRT J1745-3009, which was detected during a moderately wide-field monitoring programme of the Galactic Centre region at 0.33 GHz. The characteristics of its bursts are unlike those known for any other class of radio transient. If located in or near the Galactic Centre, its brightness temperature (approximately 10(16) K) and the implied energy density within GCRT J1745-3009 vastly exceed those observed in most other classes of radio astronomical sources, and are consistent with coherent emission processes that are rarely observed. We conclude that it represents a hitherto unknown class of transient radio sources, the first of possibly many new classes that may be discovered by emerging wide-field radio telescopes.

16.
Science ; 372(6538): 187-190, 2021 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-33833123

RESUMEN

Giant radio pulses (GRPs) are sporadic bursts emitted by some pulsars that last a few microseconds and are hundreds to thousands of times brighter than regular pulses from these sources. The only GRP-associated emission outside of radio wavelengths is from the Crab Pulsar, where optical emission is enhanced by a few percentage points during GRPs. We observed the Crab Pulsar simultaneously at x-ray and radio wavelengths, finding enhancement of the x-ray emission by 3.8 ± 0.7% (a 5.4σ detection) coinciding with GRPs. This implies that the total emitted energy from GRPs is tens to hundreds of times higher than previously known. We discuss the implications for the pulsar emission mechanism and extragalactic fast radio bursts.

17.
EClinicalMedicine ; 31: 100693, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33554084

RESUMEN

BACKGROUND: Adverse drug/device reactions (ADRs) can result in severe patient harm. We define very serious ADRs as being associated with severe toxicity, as measured on the Common Toxicity Criteria Adverse Events (CTCAE)) scale, following use of drugs or devices with large sales, large financial settlements, and large numbers of injured persons. We report on impacts on patients, clinicians, and manufacturers following very serious ADR reporting. METHODS: We reviewed clinician identified very serious ADRs published between 1997 and 2019. Drugs and devices associated with reports of very serious ADRs were identified. Included drugs or devices had market removal discussed at Food and Drug Advisory (FDA) Advisory Committee meetings, were published by clinicians, had sales > $1 billion, were associated with CTCAE Grade 4 or 5 toxicity effects, and had either >$1 billion in settlements or >1,000 injured patients. Data sources included journals, Congressional transcripts, and news reports. We reviewed data on: 1) timing of ADR reports, Boxed warnings, and product withdrawals, and 2) patient, clinician, and manufacturer impacts. Binomial analysis was used to compare sales pre- and post-FDA Advisory Committee meetings. FINDINGS: Twenty very serious ADRs involved fifteen drugs and one device. Legal settlements totaled $38.4 billion for 753,900 injured persons. Eleven of 18 clinicians (61%) reported harms, including verbal threats from manufacturer (five) and loss of a faculty position (one). Annual sales decreased 94% from $29.1 billion pre-FDA meeting to $4.9 billion afterwards (p<0.0018). Manufacturers of four drugs paid $1.7 billion total in criminal fines for failing to inform the FDA and physicians about very serious ADRs. Following FDA approval, the median time to ADR reporting was 7.5 years (Interquartile range 3,13 years). Twelve drugs received Box warnings and one drug received a warning (median, 7.5 years following ADR reporting (IQR 5,11 years). Six drugs and 1 device were withdrawn from marketing (median, 5 years after ADR reporting (IQR 4,6 years)). INTERPRETATION: Because very serious ADRs impacts are so large, policy makers should consider developing independently funded pharmacovigilance centers of excellence to assist with clinician investigations. FUNDING: This work received support from the National Cancer Institute (1R01 CA102713 (CLB), https://www.nih.gov/about-nih/what-we-do/nih-almanac/national-cancer-institute-nci; and two Pilot Project grants from the American Cancer Society's Institutional Grant Award to the University of South Carolina (IRG-13-043-01) https://www.cancer.org/ (SH; BS).

18.
Mon Not R Astron Soc ; 498(4): 4605-4614, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33149372

RESUMEN

PSR J0537-6910, also known as the Big Glitcher, is the most prolific glitching pulsar known, and its spin-induced pulsations are only detectable in X-ray. We present results from analysis of 2.7 years of NICER timing observations, from 2017 August to 2020 April. We obtain a rotation phase-connected timing model for the entire timespan, which overlaps with the third observing run of LIGO/Virgo, thus enabling the most sensitive gravitational wave searches of this potentially strong gravitational wave-emitting pulsar. We find that the short-term braking index between glitches decreases towards a value of 7 or lower at longer times since the preceding glitch. By combining NICER and RXTE data, we measure a long-term braking index n = -1.25 ± 0.01. Our analysis reveals 8 new glitches, the first detected since 2011, near the end of RXTE, with a total NICER and RXTE glitch activity of 8.88 × 10-7 yr-1. The new glitches follow the seemingly unique time-to-next-glitch-glitch-size correlation established previously using RXTE data, with a slope of 5 d µHz-1. For one glitch around which NICER observes two days on either side, we search for but do not see clear evidence of spectral nor pulse profile changes that may be associated with the glitch.

19.
PLoS One ; 15(6): e0234541, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32584835

RESUMEN

Erythropoisis stimulating agent (ESA) use was addressed in Food and Drug Administration (FDA) Oncology Drug Advisory Committee (ODAC) meetings between 2004 and 2008. FDA safety-focused regulatory actions occurred in 2007 and 2008. In 2007, black box warnings advised of early death and venous thromboembolism (VTE) risks with ESAs in oncology. In 2010, a Risk Evaluation Strategies (REMS) was initiated, with cancer patient consent that mortality and VTE risks were noted with ESAs. We report warnings and REMS impacts on ESA utilization among Veterans Administration (VA) cancer patients with chemotherapy-induced anemia (CIA). Data were from Veterans Affairs database (2003-2012). Epoetin and darbepoetin use were primary outcomes. Segmented linear regression was used to estimate changes in ESA use levels and trends, clinical appropriateness, and adverse events (VTEs) among chemotherapy-treated cancer patients. To estimate changes in level of drug prescription rate after policy actions, model-specific indicator variables as covariates based on specific actions were included. ESA use fell by 95% and 90% from 2005, for epoetin and darbepoetin, from 22% and 11%, respectively, to 1% and 1%, respectively, among cancer patients with CIA, respectively (p<0.01). Following REMS in 2010, mean hematocrit levels at ESA initiation decreased from 30% to 21% (p<0.01). Black box warnings preceded decreased ESA use among VA cancer patients with CIA. REMS was followed by reduced hematocrit levels at ESA initiation. Our findings contrast with privately- insured and Medicaid insured cancer patient data on chemotherapy-induced anemia where ESA use decreased to 3% to 7% by 2010-2012. By 2012, the era of ESA administration to VA to cancer patients had ended but the warnings remain relevant and significant. In 2019, oncology/hematology national guidelines (ASCO/ASH) recommend that cancer patients with chemotherapy-induced anemia should receive ESAs or red blood cell transfusions after risk-benefit evaluation.


Asunto(s)
Anemia/epidemiología , Antineoplásicos/efectos adversos , Hematínicos/efectos adversos , Neoplasias/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anemia/inducido químicamente , Anemia/patología , Anemia/prevención & control , Antineoplásicos/uso terapéutico , Etiquetado de Medicamentos , Femenino , Hematínicos/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/epidemiología , Neoplasias/patología , Estados Unidos/epidemiología , United States Department of Veterans Affairs , Tromboembolia Venosa , Adulto Joven
20.
Free Radic Biol Med ; 44(9): 1762-71, 2008 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-18325346

RESUMEN

Tight regulation of intracellular iron levels in response to mitochondrial dysfunction is an important mechanism that prevents oxidative stress, thereby limiting cellular damage. Here, we describe a cytoprotective response involving transcriptional activation of the ferritin H gene in response to the mitochondrial complex I inhibitor and neurotoxic compound rotenone. Rotenone exposure increased ferritin H mRNA and protein synthesis in NIH3T3 fibroblasts and SH-SY5Y neuroblastoma cells. Transient transfection of a ferritin H promoter-luciferase reporter into NIH3T3 cells showed that ferritin H was transcriptionally activated by rotenone through an antioxidant-responsive element (ARE). Chromatin immunoprecipitation assays showed that rotenone treatment enhanced binding of Nrf2 and JunD transcription factors to the ARE. In addition, rotenone induced production of reactive oxygen species (ROS), and pretreatment with N-acetylcysteine abrogated ferritin H mRNA induction by rotenone, suggesting that this response is oxidative stress-mediated. Furthermore, reduced ferritin H expression by siRNA sensitized cells to rotenone-induced apoptosis with increased ROS production and annexin V-positive cells. Taken together, these results suggest that ferritin H transcription is activated by rotenone via an oxidative stress-mediated pathway leading to ARE activation and may be critically important to protect cells from mitochondrial dysfunction and oxidative stress.


Asunto(s)
Apoferritinas/química , Regulación de la Expresión Génica , Estrés Oxidativo , Rotenona/farmacología , Animales , Antioxidantes/metabolismo , Línea Celular Tumoral , Humanos , Ratones , Mitocondrias/metabolismo , Modelos Biológicos , Factor 2 Relacionado con NF-E2/metabolismo , Células 3T3 NIH , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-jun , Desacopladores/farmacología
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