89 research outputs found
Consensus-Based Technical Recommendations for Clinical Translation of Renal Phase Contrast MRI
BACKGROUND:
Phase-contrast (PC) MRI is a feasible and valid noninvasive technique to measure renal artery blood flow, showing potential to support diagnosis and monitoring of renal diseases. However, the variability in measured renal blood flow values across studies is large, most likely due to differences in PC-MRI acquisition and processing. Standardized acquisition and processing protocols are therefore needed to minimize this variability and maximize the potential of renal PC-MRI as a clinically useful tool.
PURPOSE:
To build technical recommendations for the acquisition, processing, and analysis of renal 2D PC-MRI data in human subjects to promote standardization of renal blood flow measurements and facilitate the comparability of results across scanners and in multicenter clinical studies.
STUDY TYPE:
Systematic consensus process using a modified Delphi method.
POPULATION:
Not applicable.
SEQUENCE FIELD/STRENGTH:
Renal fast gradient echo-based 2D PC-MRI.
ASSESSMENT:
An international panel of 27 experts from Europe, the USA, Australia, and Japan with 6 (interquartile range 4–10) years of experience in 2D PC-MRI formulated consensus statements on renal 2D PC-MRI in two rounds of surveys. Starting from a recently published systematic review article, literature-based and data-driven statements regarding patient preparation, hardware, acquisition protocol, analysis steps, and data reporting were formulated.
STATISTICAL TESTS:
Consensus was defined as ≥75% unanimity in response, and a clear preference was defined as 60–74% agreement among the experts.
RESULTS:
Among 60 statements, 57 (95%) achieved consensus after the second-round survey, while the remaining three showed a clear preference. Consensus statements resulted in specific recommendations for subject preparation, 2D renal PC-MRI data acquisition, processing, and reporting.
DATA CONCLUSION:
These recommendations might promote a widespread adoption of renal PC-MRI, and may help foster the set-up of multicenter studies aimed at defining reference values and building larger and more definitive evidence, and will facilitate clinical translation of PC-MRI.
LEVEL OF EVIDENCE:
1
TECHNICAL EFFICACY STAGE:
Vacinação contra hepatite B e exposição ocupacional no setor saúde em Belo Horizonte, Minas Gerais
OBJETIVO: Identificar fatores associados à vacinação contra hepatite B em trabalhadores da saúde. MÉTODOS: Estudo transversal com 1.808 trabalhadores da saúde do setor público de Belo Horizonte, MG, em 2009. Questionário autoadministrado foi usado e a situação vacinal foi analisada considerando características sociodemográficas, estilo de vida, características e condições de trabalho. Análises estatísticas univariada (p < 0,20) e múltipla foram realizadas utilizando regressão de Poisson (p < 0,05) para avaliação de fatores associados à vacinação. RESULTADOS: Declararam ter sido vacinados 85,6% dos trabalhadores, 74,9% dos quais receberam esquema completo da vacina. Não ter sido vacinado associou-se a não ter companheiro, a escolaridade em nível médio/técnico ou superior incompleto e a características do trabalho, como atuar na vigilância ou setor administrativo/serviços gerais e não utilizar equipamentos de proteção individual. CONCLUSÕES: Foram identificados grupos com menor cobertura vacinal. São necessários esforços para garantir o acesso e a adesão à vacinação a todos os grupos ocupacionais.OBJECTIVE: To identify factors associated with vaccination against hepatitis B among healthcare workers. METHODS: This was a cross-sectional study on 1,808 public-sector healthcare workers in Belo Horizonte, Southeastern Brazil, in 2009. A self-administered questionnaire was used and the vaccination situation was analyzed taking sociodemographic characteristics, lifestyle and working conditions and characteristics into consideration. Univariate (p < 0.20) and multiple (p < 0.05) statistical analyses were performed using Poisson regression to evaluate factors associated with vaccination. RESULTS: Of the workers, 85.6% declared that they had been vaccinated, although only 74.9% of the vaccinated professionals had received a complete imunization schedule. Not having been vaccinated was associated with not having a partner; having high school, technical or incomplete higher education level; work characteristics such as working in surveillance or the administrative/general services sector; and not using personal protection equipment. CONCLUSIONS: Groups with lower vaccination coverage were identified. Efforts are required to ensure access and adherence to vaccination among healthcare workers, such as awareness-raising mechanisms.OBJETIVO: Identificar factores asociados con la vacunación contra hepatitis B en trabajadores de la salud. MÉTODOS: Estudio transversal con 1.808 trabajadores de la salud del sector público de Belo Horizonte, Sudeste de Brasil, en 2009. Se usó cuestionario auto-administrado y se analizó la situación de la vacunación considerando características sociodemográficas, estilo de vida, características y condiciones de trabajo. Se realizaron análisis estadísticos univariado (p< 0,20) y múltiple utilizando regresión de Poisson (p< 0,05) para evaluación de factores asociados con la vacunación. RESULTADOS: Declararon haber sido vacunados 85,6% de los trabajadores, 74,9% recibieron esquema completo de vacunación. No haber sido vacunado se asoció a no tener compañero, a la escolaridad en nivel medio/técnico o superior incompleto y a características de trabajo, como actuar en la vigilancia o sector administrativo/servicios generales y no utilizar equipamientos de protección individual. CONCLUSIONES: Se identificaron grupos con menor cobertura de vacunación. Son necesarios esfuerzos para garantizar el acceso y la adhesión a la vacunación entre los trabajadores de la salud, como ejemplo de mecanismos de sensibilización
Lutzomyia umbratilis, the Main Vector of Leishmania guyanensis, Represents a Novel Species Complex?
BACKGROUND: Lutzomyia umbratilis is an important Leishmania guyanensis vector in South America. Previous studies have suggested differences in the vector competence between L. umbratilis populations situated on opposite banks of the Amazonas and Negro Rivers in the central Amazonian Brazil region, likely indicating a species complex. However, few studies have been performed on these populations and the taxonomic status of L. umbratilis remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: Phylogeographic structure was estimated for six L. umbratilis samples from the central Amazonian region in Brazil by analyzing mtDNA using 1181 bp of the COI gene to assess whether the populations on opposite banks of these rivers consist of incipient or distinct species. The genetic diversity was fairly high and the results revealed two distinct clades ( = lineages) with 1% sequence divergence. Clade I consisted of four samples from the left bank of the Amazonas and Negro Rivers, whereas clade II comprised two samples from the right bank of Negro River. No haplotypes were shared between samples of two clades. Samples within clades exhibited low to moderate genetic differentiation (F(ST) = -0.0390-0.1841), whereas samples between clades exhibited very high differentiation (F(ST) = 0.7100-0.8497) and fixed differences. These lineages have diverged approximately 0.22 Mya in the middle Pleistocene. Demographic expansion was detected for the lineages I and II approximately 30,448 and 15,859 years ago, respectively, in the late Pleistocene. CONCLUSIONS/SIGNIFICANCE: The two genetic lineages may represent an advanced speciation stage suggestive of incipient or distinct species within L. umbratilis. These findings suggest that the Amazonas and Negro Rivers may be acting as effective barriers, thus preventing gene flow between populations on opposite sides. Such findings have important implications for epidemiological studies, especially those related to vector competence and anthropophily, and for vector control strategies. In addition, L. umbratilis represents an interesting example in speciation studies
Excessive substance use in bipolar disorder is associated with impaired functioning rather than clinical characteristics, a descriptive study
<p>Abstract</p> <p>Background</p> <p>There is a strong association between bipolar disorder (BD) and substance use disorder (SUD). The clinical and functional correlates of SUD in BD are still unclear and little is known about the role of excessive substance use that does not meet SUD criteria. Thus, the aims of the current study were to investigate lifetime rates of illicit substance use in BD relative to the normal population and if there are differences in clinical and functional features between BD patients with and without excessive substance use.</p> <p>Methods</p> <p>125 consecutively recruited BD in- and outpatients from the Oslo University Hospitals and 327 persons randomly drawn from the population in Oslo, Norway participated. Clinical and functional variables were assessed. Excessive substance use was defined as DSM-IV SUD and/or excessive use according to predefined criteria.</p> <p>Results</p> <p>The rate of lifetime illicit substance use was significantly higher among patients compared to the reference population (OR = 3.03, CI = 1.9-4.8, p < .001). Patients with excessive substance use (45% of total) had poorer educational level, occupational status, GAF-scores and medication compliance, with a trend towards higher suicidality rates, compared to patients without. There were no significant group differences in current symptom levels or disease course between groups.</p> <p>Conclusion</p> <p>The percentage of patients with BD that had tried illicit substances was significantly higher than in the normal population. BD patients with excessive substance use clearly had impaired functioning, but not a worse course of illness compared to patients without excessive substance use. An assessment of substance use beyond SUD criteria in BD is clinically relevant.</p
Effort-reward imbalance at work is predicted by temporal and energetic characteristics of behavior: A population-based study
Objective: Personality dispositions may influence perceptions of work stress. The paper examines the relationship between temperament in terms of Strelau's Regulative Theory of Temperament and the effort-reward imbalance and its components. Material and Methods: There were 890 participants (360 men) aged 37.9 years on average. Temperament traits of briskness and perseveration (temporal characteristics of behavior), sensory sensitivity, emotional reactivity, endurance and activity (energetic characteristics of behavior) were measured by Strelau & Zawadzki's Formal Characteristics of Behavior-Temperament Inventory (FCB-TI) in 1997 and 2001. Effort and reward at work were assessed with the original effortreward imbalance (ERI) questionnaire of 2007. Results: Higher ERI at work was predicted by higher emotional reactivity, higher perseveration, lower briskness, and lower endurance. Higher effort and lower rewards at work were predicted by higher perseveration and lower endurance. The FCB-TI temperament characteristics accounted for 5.2%, 4.8% and 6.5% of the variance in the ERI, effort and reward, respectively. Lower emotional reactivity, lower perseveration, higher briskness and higher endurance predicted higher esteem at work, job promotion and job security. Conclusions: Individual differences in arousability, reflected in temporal and energetic characteristics of behavior, may predispose to or to protect from an effort-reward imbalance at work. Individual differences should be acknowledged in work stress prevention and developing interventions
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory. The probability of the near-simultaneous temporal and spatial observation of GRB 170817A and GW170817 occurring by chance is . We therefore confirm binary neutron star mergers as a progenitor of short GRBs. The association of GW170817 and GRB 170817A provides new insight into fundamental physics and the origin of short GRBs. We use the observed time delay of between GRB 170817A and GW170817 to: (i) constrain the difference between the speed of gravity and the speed of light to be between and times the speed of light, (ii) place new bounds on the violation of Lorentz invariance, (iii) present a new test of the equivalence principle by constraining the Shapiro delay between gravitational and electromagnetic radiation. We also use the time delay to constrain the size and bulk Lorentz factor of the region emitting the gamma-rays. GRB 170817A is the closest short GRB with a known distance, but is between 2 and 6 orders of magnitude less energetic than other bursts with measured redshift. A new generation of gamma-ray detectors, and subthreshold searches in existing detectors, will be essential to detect similar short bursts at greater distances. Finally, we predict a joint detection rate for the Fermi Gamma-ray Burst Monitor and the Advanced LIGO and Virgo detectors of 0.1-1.4 per year during the 2018-2019 observing run and 0.3-1.7 per year at design sensitivity
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