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1.
J Cutan Pathol ; 2024 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-38797972

RESUMEN

Cutaneous spindle cell neoplasms can be challenging to diagnose using routine histopathological techniques alone, and the growing repertoire of molecular studies can assist in diagnosis. We describe a cutaneous spindle cell neoplasm characterized by a COL3A1::PDGFRA rearrangement predicted to lead to constitutive activation of the PDGFRA kinase domain. The lesion shows some similarities to dermatofibrosarcoma protuberans and also benign and epithelioid fibrous histiocytomas but is distinct from these entities histopathologically and molecularly. This tumor is considered to represent an entity in the spectrum of PDGFR-driven cutaneous mesenchymal neoplasms.

2.
Am Fam Physician ; 107(2): 145-151, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36791445

RESUMEN

Acute otitis externa is an inflammatory condition that affects the external ear canal. It is usually of rapid onset and is generally caused by bacterial infection. The primary bacterial infections are Pseudomonas aeruginosa and Staphylococcus aureus. Acute otitis externa presents with pain (otalgia), redness, and swelling of the canal. It is more common in children and young adults. Tenderness on movement of the pinna or tragus is the classic finding. Analgesics and topical antibiotics are the mainstays of therapy. Topical medications include acetic acid 2%, aminoglycosides, polymyxin B, and quinolones with and without corticosteroids. There is no evidence that any one preparation is clinically superior to another, and the choice of treatment is based on factors such as cost, whether the tympanic membrane is intact, and patient adherence. Oral antibiotics are indicated only if evidence of cellulitis occurs outside of the ear canal or if associated conditions such as immunocompromise, diabetes mellitus, or conditions that would not allow for the use of topical treatment are found. Duration of topical treatment is usually seven to 10 days. Keys to prevention include avoiding injury to the ear canal and keeping it free of water.


Asunto(s)
Otitis Externa , Niño , Humanos , Adulto Joven , Ácido Acético/uso terapéutico , Enfermedad Aguda , Analgésicos/uso terapéutico , Antibacterianos/uso terapéutico , Conducto Auditivo Externo , Otitis Externa/diagnóstico , Otitis Externa/tratamiento farmacológico , Otitis Externa/microbiología
3.
Radiology ; 298(3): 640-651, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33464181

RESUMEN

Background Proton density fat fraction (PDFF) estimated by using chemical shift-encoded (CSE) MRI is an accepted imaging biomarker of hepatic steatosis. This work aims to promote standardized use of CSE MRI to estimate PDFF. Purpose To assess the accuracy of CSE MRI methods for estimating PDFF by determining the linearity and range of bias observed in a phantom. Materials and Methods In this prospective study, a commercial phantom with 12 vials of known PDFF values were shipped across nine U.S. centers. The phantom underwent 160 independent MRI examinations on 27 1.5-T and 3.0-T systems from three vendors. Two three-dimensional CSE MRI protocols with minimal T1 bias were included: vendor and standardized. Each vendor's confounder-corrected complex or hybrid magnitude-complex based reconstruction algorithm was used to generate PDFF maps in both protocols. The Siemens reconstruction required a configuration change to correct for water-fat swaps in the phantom. The MRI PDFF values were compared with the known PDFF values by using linear regression with mixed-effects modeling. The 95% CIs were calculated for the regression slope (ie, proportional bias) and intercept (ie, constant bias) and compared with the null hypothesis (slope = 1, intercept = 0). Results Pooled regression slope for estimated PDFF values versus phantom-derived reference PDFF values was 0.97 (95% CI: 0.96, 0.98) in the biologically relevant 0%-47.5% PDFF range. The corresponding pooled intercept was -0.27% (95% CI: -0.50%, -0.05%). Across vendors, slope ranges were 0.86-1.02 (vendor protocols) and 0.97-1.0 (standardized protocol) at 1.5 T and 0.91-1.01 (vendor protocols) and 0.87-1.01 (standardized protocol) at 3.0 T. The intercept ranges (absolute PDFF percentage) were -0.65% to 0.18% (vendor protocols) and -0.69% to -0.17% (standardized protocol) at 1.5 T and -0.48% to 0.10% (vendor protocols) and -0.78% to -0.21% (standardized protocol) at 3.0 T. Conclusion Proton density fat fraction estimation derived from three-dimensional chemical shift-encoded MRI in a commercial phantom was accurate across vendors, imaging centers, and field strengths, with use of the vendors' product acquisition and reconstruction software. © RSNA, 2021 See also the editorial by Dyke in this issue.


Asunto(s)
Hígado Graso/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Fantasmas de Imagen , Algoritmos , Biomarcadores , Humanos , Procesamiento de Imagen Asistido por Computador , Imagenología Tridimensional , Estudios Prospectivos , Protones , Reproducibilidad de los Resultados , Estados Unidos
4.
Nat Mater ; 19(2): 195-202, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31792424

RESUMEN

Membranes with fast and selective ion transport are widely used for water purification and devices for energy conversion and storage including fuel cells, redox flow batteries and electrochemical reactors. However, it remains challenging to design cost-effective, easily processed ion-conductive membranes with well-defined pore architectures. Here, we report a new approach to designing membranes with narrow molecular-sized channels and hydrophilic functionality that enable fast transport of salt ions and high size-exclusion selectivity towards small organic molecules. These membranes, based on polymers of intrinsic microporosity containing Tröger's base or amidoxime groups, demonstrate that exquisite control over subnanometre pore structure, the introduction of hydrophilic functional groups and thickness control all play important roles in achieving fast ion transport combined with high molecular selectivity. These membranes enable aqueous organic flow batteries with high energy efficiency and high capacity retention, suggesting their utility for a variety of energy-related devices and water purification processes.

6.
Magn Reson Med ; 86(3): 1194-1211, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33847012

RESUMEN

PURPOSE: A standard MRI system phantom has been designed and fabricated to assess scanner performance, stability, comparability and assess the accuracy of quantitative relaxation time imaging. The phantom is unique in having traceability to the International System of Units, a high level of precision, and monitoring by a national metrology institute. Here, we describe the phantom design, construction, imaging protocols, and measurement of geometric distortion, resolution, slice profile, signal-to-noise ratio (SNR), proton-spin relaxation times, image uniformity and proton density. METHODS: The system phantom, designed by the International Society of Magnetic Resonance in Medicine ad hoc committee on Standards for Quantitative MR, is a 200 mm spherical structure that contains a 57-element fiducial array; two relaxation time arrays; a proton density/SNR array; resolution and slice-profile insets. Standard imaging protocols are presented, which provide rapid assessment of geometric distortion, image uniformity, T1 and T2 mapping, image resolution, slice profile, and SNR. RESULTS: Fiducial array analysis gives assessment of intrinsic geometric distortions, which can vary considerably between scanners and correction techniques. This analysis also measures scanner/coil image uniformity, spatial calibration accuracy, and local volume distortion. An advanced resolution analysis gives both scanner and protocol contributions. SNR analysis gives both temporal and spatial contributions. CONCLUSIONS: A standard system phantom is useful for characterization of scanner performance, monitoring a scanner over time, and to compare different scanners. This type of calibration structure is useful for quality assurance, benchmarking quantitative MRI protocols, and to transition MRI from a qualitative imaging technique to a precise metrology with documented accuracy and uncertainty.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Fantasmas de Imagen , Relación Señal-Ruido
7.
J Magn Reson Imaging ; 51(2): 331-338, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31355502

RESUMEN

The need for a guidance document on MR safe practices arose from a growing awareness of the MR environment's potential risks and adverse event reports involving patients, equipment, and personnel. Initially published in 2002, the American College of Radiology White Paper on MR Safety established de facto industry standards for safe and responsible practices in clinical and research MR environments. The most recent version addresses new sources of risk of adverse events, increases awareness of dynamic MR environments, and recommends that those responsible for MR medical director safety undergo annual MR safety training. With regular updates to these guidelines, the latest MR safety concerns can be accounted for to ensure a safer MR environment where dangers are minimized. Level of Evidence: 1 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2020;51:331-338.


Asunto(s)
Imagen por Resonancia Magnética , Humanos
8.
J Synchrotron Radiat ; 26(Pt 6): 1986-1995, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31721744

RESUMEN

Synthesis and immobilization of caltrop cupric particles onto a Si substrate using X-ray radiolysis directly from a liquid solution of Cu(COOCH3)2 is demonstrated. Caltrop cupric oxide particles are formed in the X-ray radiolysis of aqueous solutions of Cu(COOCH3)2, which also contain methanol, ethanol, 2-propanol or 1-propanol as ^\bulletOH scavenger. The blade lengths of the caltrop particles are dependent on the alcohol chain length. In particular, it was found that an alkyl alcohol whose chain length is longer than four is unable to synthesize any particles in aqueous solutions of Cu(COOCH3)2 in X-ray radiolysis. These results are attributed to the alkyl alcohol chain length influencing the rate of reaction of radicals and determines the solvable ratio of its alcohol into water. In addition, it was found that the synthesized particle geometric structure and composition can also be controlled by the pH of the aqueous solution in the X-ray radiolysis. This study may open a door to understanding and investigating a novel photochemical reaction route induced under X-ray irradiation. The development of the X-ray radiolysis process enables us to achieve the rapid and easy process of synthesis and immobilization of higher-order nano/microstructure consisting of various materials.

9.
J Magn Reson Imaging ; 49(7): e101-e121, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30451345

RESUMEN

Physiological properties of tumors can be measured both in vivo and noninvasively by diffusion-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging. Although these techniques have been used for more than two decades to study tumor diffusion, perfusion, and/or permeability, the methods and studies on how to reduce measurement error and bias in the derived imaging metrics is still lacking in the literature. This is of paramount importance because the objective is to translate these quantitative imaging biomarkers (QIBs) into clinical trials, and ultimately in clinical practice. Standardization of the image acquisition using appropriate phantoms is the first step from a technical performance standpoint. The next step is to assess whether the imaging metrics have clinical value and meet the requirements for being a QIB as defined by the Radiological Society of North America's Quantitative Imaging Biomarkers Alliance (QIBA). The goal and mission of QIBA and the National Cancer Institute Quantitative Imaging Network (QIN) initiatives are to provide technical performance standards (QIBA profiles) and QIN tools for producing reliable QIBs for use in the clinical imaging community. Some of QIBA's development of quantitative diffusion-weighted imaging and dynamic contrast-enhanced QIB profiles has been hampered by the lack of literature for repeatability and reproducibility of the derived QIBs. The available research on this topic is scant and is not in sync with improvements or upgrades in MRI technology over the years. This review focuses on the need for QIBs in oncology applications and emphasizes the importance of the assessment of their reproducibility and repeatability. Level of Evidence: 5 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2019;49:e101-e121.


Asunto(s)
Biomarcadores , Imagen de Difusión por Resonancia Magnética/métodos , Neoplasias/diagnóstico por imagen , Adulto , Anciano , Encéfalo/diagnóstico por imagen , Ensayos Clínicos como Asunto , Medios de Contraste , Femenino , Humanos , Hígado/diagnóstico por imagen , Masculino , Oncología Médica/normas , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Neuroimagen/métodos , Fantasmas de Imagen , Próstata/diagnóstico por imagen , Reproducibilidad de los Resultados
11.
AIDS Behav ; 23(11): 2936-2945, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31321638

RESUMEN

This project established a faith-based, university-community partnership with the African Methodist Episcopal (AME) church in Alabama to develop a statewide training model to address HIV knowledge and stigma, promote discussion and generate action plans to address HIV in the Deep South. A community-engaged research team consisting of church leadership and university researchers developed and implemented the model, "Love with No Exceptions." Mixed methods were used to evaluate the model delivered in 3-h sessions in five state regions (N = 146 clergy and laity). The majority of participants reported feeling better prepared to serve those living with or affected by HIV and would implement education and awareness activities in their churches. Participants' HIV knowledge increased from pre- to post-training. Stigma-related attitudes showed minor changes from baseline. These results reflect that partnerships between academic institutions and churches can deliver promising steps towards impactful HIV education in the Deep South.


Asunto(s)
Negro o Afroamericano/psicología , Clero , Infecciones por VIH/prevención & control , Infecciones por VIH/psicología , Educación en Salud/métodos , Conocimientos, Actitudes y Práctica en Salud , Religión , Estigma Social , Adulto , Anciano , Alabama , Creación de Capacidad , Investigación Participativa Basada en la Comunidad , Discriminación en Psicología , Femenino , Infecciones por VIH/etnología , Promoción de la Salud/métodos , Humanos , Liderazgo , Amor , Masculino , Persona de Mediana Edad , Estados Unidos , Universidades
12.
AIDS Behav ; 23(Suppl 3): 319-330, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31444712

RESUMEN

Nearly half of HIV infections in the United States are concentrated among African Americans, and over half of new HIV infections occur in the South. African Americans have poorer outcomes in the entire continua of HIV and PrEP care. Complex social, structural, and behavioral factors contribute to our nation's alarming racial disparities in HIV infection, particularly in the Deep South. Despite the importance of faith, spirituality and religious practice in the lives of many African Americans, there has been little scientific investment exploring how African Americans' religious participation, faith and spirituality may impact our nation's HIV epidemic. This article summarizes the state of the science on this critical issue. We also identify opportunities for new scholarship on how faith, spirituality and religious participation may impact HIV care continuum outcomes in the South and call for greater federal research investment on these issues.


Asunto(s)
Negro o Afroamericano/psicología , Continuidad de la Atención al Paciente , Organizaciones Religiosas , Infecciones por VIH/etnología , Infecciones por VIH/psicología , Negro o Afroamericano/estadística & datos numéricos , Epidemias , Infecciones por VIH/prevención & control , Humanos , Espiritualidad , Estados Unidos
13.
Sociol Health Illn ; 41(3): 484-501, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30450606

RESUMEN

The advancements of "treatment as prevention" (TasP), "undetectable viral load" (UVL) and "pre-exposure prophylaxis" (PrEP) are redefining HIV prevention standards. Relying on the concept of biosociality, this article explores how gay men rally around, debate, and sometimes disagree about these emerging HIV prevention technologies. This article is based on data from the Resonance Project, a Canadian community-based research project. Twelve focus groups (totalling 86 gay and bisexual men) were held in three Canadian cities (Montreal, Toronto, Vancouver) in 2013-2014. Respondents view UVL and PrEP through the prism of their generational experience of HIV prevention. In this respect, biosocialities highlight an experiential dimension that is tied to the context of the HIV epidemic. The biosocialities of HIV prevention are also built around serological identities. However, our study shows the diversity of these positions. Analysis grounded in biosocialities is useful for better understanding how scientific information circulates, is made sense of, and generates debate among gay men.


Asunto(s)
Antirretrovirales/administración & dosificación , Bisexualidad/psicología , Infecciones por VIH/prevención & control , Homosexualidad Masculina/psicología , Profilaxis Pre-Exposición/métodos , Minorías Sexuales y de Género/psicología , Adulto , Canadá , Investigación Participativa Basada en la Comunidad , Grupos Focales , Infecciones por VIH/virología , Humanos , Masculino , Persona de Mediana Edad , Grupos Raciales , Conducta de Reducción del Riesgo , Asunción de Riesgos , Responsabilidad Social , Carga Viral
14.
Magn Reson Med ; 79(1): 48-61, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29083101

RESUMEN

The MRI community is using quantitative mapping techniques to complement qualitative imaging. For quantitative imaging to reach its full potential, it is necessary to analyze measurements across systems and longitudinally. Clinical use of quantitative imaging can be facilitated through adoption and use of a standard system phantom, a calibration/standard reference object, to assess the performance of an MRI machine. The International Society of Magnetic Resonance in Medicine AdHoc Committee on Standards for Quantitative Magnetic Resonance was established in February 2007 to facilitate the expansion of MRI as a mainstream modality for multi-institutional measurements, including, among other things, multicenter trials. The goal of the Standards for Quantitative Magnetic Resonance committee was to provide a framework to ensure that quantitative measures derived from MR data are comparable over time, between subjects, between sites, and between vendors. This paper, written by members of the Standards for Quantitative Magnetic Resonance committee, reviews standardization attempts and then details the need, requirements, and implementation plan for a standard system phantom for quantitative MRI. In addition, application-specific phantoms and implementation of quantitative MRI are reviewed. Magn Reson Med 79:48-61, 2018. © 2017 International Society for Magnetic Resonance in Medicine.


Asunto(s)
Mapeo Encefálico/métodos , Imagen por Resonancia Magnética/métodos , Fantasmas de Imagen , Algoritmos , Biomarcadores/metabolismo , Calibración , Medios de Contraste/química , Elasticidad , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Lineales , Modelos Teóricos , Perfusión , Valores de Referencia , Reproducibilidad de los Resultados , Relación Señal-Ruido
15.
Mol Ther ; 24(9): 1627-33, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27375160

RESUMEN

Oncolytic viruses (OV) could become the most powerful and selective cancer therapies. However, the limited transport of OV into and throughout tumors following intravenous injection means their clinical administration is often restricted to direct intratumoral dosing. Application of physical stimuli, such as focused ultrasound, offers a means of achieving enhanced mass transport. In particular, shockwaves and microstreaming resulting from the instigation of an ultrasound-induced event known as inertial cavitation can propel OV hundreds of microns. We have recently developed a polymeric cup formulation which, when delivered intravenously, provides the nuclei for instigation of sustained inertial cavitation events within tumors. Here we report that exposure of tumors to focused ultrasound after intravenous coinjection of cups and oncolytic vaccinia virus , leads to substantial and significant increases in activity. When cavitation was instigated within SKOV-3 or HepG2 xenografts, reporter gene expression from vaccinia virus was enhanced 1,000-fold (P < 0.0001) or 10,000-fold (P < 0.001), respectively. Similar increases in the number of vaccinia virus genomes recovered from tumors were also observed. In survival studies, the application of cup mediated cavitation to a vaccinia virus expressing a prodrug converting enzyme provided significant (P < 0.05) retardation of tumor growth. This technology could improve the clinical utility of all biological therapeutics including OV.


Asunto(s)
Técnicas de Transferencia de Gen , Vectores Genéticos/genética , Viroterapia Oncolítica , Virus Oncolíticos/genética , Virus Vaccinia/genética , Animales , Línea Celular Tumoral , Modelos Animales de Enfermedad , Fluorouracilo/farmacología , Vectores Genéticos/administración & dosificación , Humanos , Ratones , Neoplasias/genética , Neoplasias/patología , Neoplasias/terapia , Viroterapia Oncolítica/métodos , Transducción Genética , Resultado del Tratamiento , Carga Tumoral/efectos de los fármacos , Carga Tumoral/genética , Ensayos Antitumor por Modelo de Xenoinjerto
16.
J Appl Clin Med Phys ; 18(6): 275-287, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29125231

RESUMEN

PURPOSE: The education and training landscape has been profoundly reshaped by the ABR 2012/2014 initiative and the MedPhys Match. This work quantifies these changes and summarizes available reports, surveys, and statistics on education and training. METHODS: We evaluate data from CAMPEP-accredited program websites, annual CAMPEP graduate and residency program reports, and surveys on the MedPhys Match and Professional Doctorate degree (DMP). RESULTS: From 2009-2015, the number of graduates from CAMPEP-accredited graduate programs rose from 210 to 332, while CAMPEP-accredited residency positions rose from 60 to 134. We estimate that approximately 60% of graduates of CAMPEP-accredited graduate programs intend to enter clinical practice, however, only 36% of graduates were successful in acquiring a residency position in 2015. The maximum residency placement percentage for a graduate program is 70%, while the median for all programs is only 22%. Overall residency placement percentage for CAMPEP-accredited program graduates from 2011-2015 was approximately 38% and 25% for those with a PhD and MS, respectively. The disparity between the number of clinically oriented graduates and available residency positions is perceived as a significant problem by over 70% of MedPhys Match participants responding to a post-match survey. Approximately 32% of these respondents indicated that prior knowledge of this situation would have changed their decision to pursue graduate education in medical physics. CONCLUSION: These data reveal a substantial disparity between the number of residency training positions and graduate students interested in these positions, and a substantial variability in residency placement percentage across graduate programs. Comprehensive data regarding current and projected supply and demand within the medical physics workforce are needed for perspective on these numbers. While the long-term effects of changes in the education and training infrastructure are still unclear, available survey data suggest that these changes could negatively affect potential entrants to the profession.


Asunto(s)
Competencia Clínica , Educación de Postgrado en Medicina/métodos , Física Sanitaria/educación , Internado y Residencia/normas , Oncología por Radiación/educación , Habilitación Profesional , Evaluación Educacional , Humanos
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