144 research outputs found
Non-immune fetal hydrops: etiology and outcome according to gestational age at diagnosis.
OBJECTIVE: Fetal hydrops is associated with increased perinatal morbidity and mortality. The etiology and outcome of fetal hydrops may differ according to the gestational age at diagnosis. The aim of this study was to evaluate the cause, evolution and outcome of non-immune fetal hydrops (NIFH), according to the gestational age at diagnosis. METHODS: This was a retrospective cohort study of all singleton pregnancies complicated by NIFH, at the Fetal Medicine Unit at St George's University Hospital, London, UK, between 2000 and 2018. All fetuses had detailed anomaly and cardiac ultrasound scans, karyotyping and infection screening. Prenatal diagnostic and therapeutic intervention, gestational age at diagnosis and delivery, as well as pregnancy outcome, were recorded. Regression analysis was used to test for potential association between possible risk factors and perinatal mortality. RESULTS: We included 273 fetuses with NIFH. The etiology of the condition varied significantly in the three trimesters. Excluding 30 women who declined invasive testing, the cause of NIFH was defined as unknown in 62 of the remaining 243 cases (25.5%). Chromosomal aneuploidy was the most common cause of NIFH in the first trimester. It continued to be a significant etiologic factor in the second trimester, along with congenital infection. In the third trimester, the most common etiology was cardiovascular abnormality. Among the 152 (55.7%) women continuing the pregnancy, 48 (31.6%) underwent fetal intervention, including the insertion of pleuroamniotic shunts, fetal blood transfusion and thoracentesis. Fetal intervention was associated significantly with lower perinatal mortality (odds ratio (OR), 0.30 (95% CI, 0.14-0.61); P 0.05). CONCLUSIONS: An earlier gestational age at diagnosis of NIFH was associated with an increased risk of aneuploidy and worse pregnancy outcome, including a higher risk of perinatal loss. Fetal therapy was associated significantly with lower perinatal mortality. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology
Bioinformática : base de datos de matrices de expresión génica para su análisis vía web
El IBB ha desarrollado un servidor de aplicaciones: http://revolutionresearch.uab.es para el análisis de microarrays. Estas microarrays las obtienen y las suben a la base de datos local los usuarios de la aplicación. En la presente memoria se detalla el proceso realizado para automatizar la subida de microarrays públicas a la base de datos local. Estas microarrays se obtendrán del NCBI. El proceso de descarga de microarrays se realizará cada dos meses y estará sincronizado con un proceso de descarga de genes marcadores de microarrays del NCBI. En la memoria también se describen las fases realizadas para crear la interfaz web para gestionar estas microarrays públicas y las modificaciones realizadas sobre el aplicativo web para permitir realizar análisis con estas microarrays.L' IBB ha desenvolupat un servidor d'aplicacions: http://revolutionresearch.uab.es per l'anàlisi de microarrays. Aquestes microarrays les obtenen y les pugen a la base de dades local els usuaris de l'aplicació. En la present memòria es detalla el procés realitzat para automatitzar la pujada de microarrays públiques a la base de dades local. Aquestes microarrays s'obtindran del NCBI. El procés de descarrega de microarrays es realitzarà cada dos mesos y estarà sincronitzat amb un procés de descarrega de gens marcadors de microarrays del NCBI. A la memòria també es descriuen las fases realitzades per crear la interfície web para gestionar aquestes microarrays públiques y las modificacions realitzades sobre l'aplicatiu web per permetre realitzar anàlisis amb aquestes microarrays.The IBB center has developed a application server: http://revolutionresearch.uab.es to analyze the microarrays. These microarrays are obtained and uploaded to the local database by the application users. This report details the process undertaken in order to automate the public microarrays upload to the local database. These microarrays will obtain from the NCBI. The download process will perform every two months and will be synchronized with a download process of gene markers of the NCBI. The report also describes the steps taken to create the web interface to manage these public microarrays and the changes made on the web application to allow these microarray analysis
Prospective cohort study of procalcitonin levels in children with cancer presenting with febrile neutropenia
BACKGROUND: Febrile neutropenia (FNP) causes significant morbidity and mortality in children undergoing treatment for cancer. The development of clinical decision rules to help stratify risks in paediatric FNP patients and the use of inflammatory biomarkers to identify high risk patients is an area of recent research. This study aimed to assess if procalcitonin (PCT) levels could be used to help diagnose or exclude severe infection in children with cancer who present with febrile neutropenia, both as a single measurement and in addition to previously developed clinical decision rules. METHODS: This prospective cohort study of a diagnostic test included patients between birth and 18 years old admitted with febrile neutropenia to the Paediatric Oncology and Haematology Ward in Leeds between 1(st) October 2012 and 30(th) September 2013. Each admission with FNP was treated as a separate episode. Blood was taken for a procalcitonin level at admission with routine investigations. 'R' was used for statistical analysis. Likelihood ratios were calculated and multivariable logistic regression. RESULTS: Forty-eight episodes from 27 patients were included. PCT >2 ng/dL was strongly associated with increased risk of severe infection (likelihood ratio of 26 [95% CI 3.5, 190]). The data suggests that the clinical decision rules are largely ineffective at risk stratification, frequently over-stating the risk of individual episodes. High procalcitonin levels on admission are correlated with a greatly increased risk of severe infection. CONCLUSIONS: This study does not show a definitive benefit in using PCT in FNP though it supports further research on its use. The benefit of novel biomarkers has not been proven and before introducing new tests for patients it is important their benefit above existing features is proven, particularly due to the increasing importance of health economics
B-type supergiants in the SMC: Rotational velocities and implications for evolutionary models
High-resolution spectra for 24 SMC and Galactic B-type supergiants have been
analysed to estimate the contributions of both macroturbulence and rotation to
the broadening of their metal lines. Two different methodologies are
considered, viz. goodness-of-fit comparisons between observed and theoretical
line profiles and identifying zeros in the Fourier transforms of the observed
profiles. The advantages and limitations of the two methods are briefly
discussed with the latter techniques being adopted for estimated projected
rotational velocities (\vsini) but the former being used to estimate
macroturbulent velocities. Only one SMC supergiant, SK 191, shows a significant
degree of rotational broadening (\vsini 90 \kms). For the remaining
targets, the distribution of projected rotational velocities are similar in
both our Galactic and SMC samples with larger values being found at earlier
spectral types. There is marginal evidence for the projected rotational
velocities in the SMC being higher than those in the Galactic targets but any
differences are only of the order of 5-10 \kms, whilst evolutionary models
predict differences in this effective temperature range of typically 20 to 70
\kms. The combined sample is consistent with a linear variation of projected
rotational velocity with effective temperature, which would imply rotational
velocities for supergiants of 70 \kms at an effective temperature of 28 000 K
(approximately B0 spectral type) decreasing to 32 \kms at 12 000 K (B8 spectral
type). For all targets, the macroturbulent broadening would appear to be
consistent with a Gaussian distribution (although other distributions cannot be
discounted) with an half-width varying from approximately 20 \kms
at B8 to 60 \kms at B0 spectral types.Comment: 4 figures, 8 pages, submitted to Astronomy and Astrophysic
Current status of NLTE analysis of stellar atmospheres
Various available codes for NLTE modeling and analysis of hot star spectra
are reviewed. Generalizations of standard equations of kinetic equilibrium and
their consequences are discussed.Comment: in Determination of Atmospheric Parameters of B-, A-, F- and G-Type
Stars, E. Niemczura et al. eds., Springer, in pres
Terminal velocities of luminous, early-type SMC stars
Ultraviolet spectra from the Space Telescope Imaging Spectrograph (STIS) are
used to determine terminal velocities for 11 O and B-type giants and
supergiants in the Small Magellanic Cloud (SMC) from the Si IV and C IV
resonance lines. Using archival data from observations with the Goddard
High-Resolution Spectrograph and the International Ultraviolet Explorer
telescope, terminal velocities are obtained for a further five B-type
supergiants. We discuss the metallicity dependence of stellar terminal
velocities, finding no evidence for a significant scaling between Galactic and
SMC metallicities for Teff < 30,000 K, consistent with the predictions of
radiation driven wind theory for supergiant stars. A comparison of the
ratio between the SMC and Galactic samples, while
consistent with the above statement, emphasizes that the uncertainties in the
distances to galactic O-stars are a serious obstacle to a detailed comparison
with theory. For the SMC sample there is considerable scatter in this ratio at
a given effective temperature, perhaps indicative of uncertainties in stellar
masses.Comment: 28 pages, 8 figures, accepted by ApJ; minor revisions prior to
acceptanc
Atmospheric parameters and rotational velocities for a sample of Galactic B-type supergiants
High resolution optical spectra of 57 Galactic B-type supergiant stars have
been analyzed to determine their rotational and macroturbulent velocities. In
addition, their atmospheric parameters (effective temperature, surface gravity
and microturbulent velocity) and surface nitrogen abundances have been
estimated using a non-LTE grid of model atmospheres. Comparisons of the
projected rotational velocities have been made with the predictions of stellar
evolutionary models and in general good agreement was found. However for a
small number of targets, their observed rotational velocities were
significantly larger than predicted, although their nitrogen abundances were
consistent with the rest of the sample. We conclude that binarity may have
played a role in generating their large rotational velocities. No correlation
was found between nitrogen abundances and the current projected rotational
velocities. However a correlation was found with the inferred projected
rotational velocities of the main sequence precursors of our supergiant sample.
This correlation is again in agreement with the predictions of single star
evolutionary models that incorporate rotational mixing. The origin of the
macroturbulent and microturbulent velocity fields is discussed and our results
support previous theoretical studies that link the former to sub-photospheric
convection and the latter to non-radial gravity mode oscillations. In addition,
we have attempted to identify differential rotation in our most rapidly
rotating targets.Comment: Submitted to MNRAS, 16 page
MY Camelopardalis, a very massive merger progenitor
Context. The early-type binary MY Cam belongs to the young open cluster
Alicante 1, embedded in Cam OB3. Aims. MY Cam consists of two early-O type
main-sequence stars and shows a photometric modulation suggesting an orbital
period slightly above one day. We intend to confirm this orbital period and
derive orbital and stellar parameters. Methods. Timing analysis of a very
exhaustive (4607 points) light curve indicates a period of 1.1754514 +-
0.0000015 d. High- resolution spectra and the cross-correlation technique
implemented in the TODCOR program were used to derive radial velocities and
obtain the corresponding radial velocity curves for MY Cam. Modelling with the
stellar atmosphere code FASTWIND was used to obtain stellar parameters and
create templates for cross-correlation. Stellar and orbital parameters were
derived using the Wilson-Devinney code, such that a complete solution to the
binary system could be described. Results. The determined masses of the primary
and secondary stars in MY Cam are 37.7 +- 1.6 and 31.6 +- 1.4 Msol,
respectively. The corresponding temperatures, derived from the model atmosphere
fit, are 42 000 and 39 000 K, with the more massive component being hotter.
Both stars are overfilling their Roche lobes, sharing a common envelope.
Conclusions. MY Cam contains the most massive dwarf O-type stars found so far
in an eclipsing binary. Both components are still on the main sequence, and
probably not far from the zero-age main sequence. The system is a likely merger
progenitor, owing to its very short period.Comment: 8 pages, 6 figures, photometric data available on-line, Astronomy and
Astrophysics, 201
Epidemiology of Candidemia in Latin America: A Laboratory-Based Survey
Background: the epidemiology of candidemia varies depending on the geographic region. Little is known about the epidemiology of candidemia in Latin America.Methods: We conducted a 24-month laboratory-based survey of candidemia in 20 centers of seven Latin American countries. Incidence rates were calculated and the epidemiology of candidemia was characterized.Results: Among 672 episodes of candidemia, 297 (44.2%) occurred in children (23.7% younger than 1 year), 36.2% in adults between 19 and 60 years old and 19.6% in elderly patients. the overall incidence was 1.18 cases per 1,000 admissions, and varied across countries, with the highest incidence in Colombia and the lowest in Chile. Candida albicans (37.6%), C. parapsilosis (26.5%) and C. tropicalis (17.6%) were the leading agents, with great variability in species distribution in the different countries. Most isolates were highly susceptible to fluconazole, voriconazole, amphotericin B and anidulafungin. Fluconazole was the most frequent agent used as primary treatment (65.8%), and the overall 30-day survival was 59.3%.Conclusions: This first large epidemiologic study of candidemia in Latin America showed a high incidence of candidemia, high percentage of children, typical species distribution, with C. albicans, C. parapsilosis and C. tropicalis accounting for the majority of episodes, and low resistance rates.independent medical grant from Pfizer Inc.Univ Fed Rio de Janeiro, Univ Hosp, Rio de Janeiro, BrazilUniv Fed Parana, Hosp Clin, BR-80060000 Curitiba, Parana, BrazilHosp Escuela Tegucigalpa, Tegucigalpa, HondurasHosp Clin Jose San Martin, Buenos Aires, DF, ArgentinaUniv Nacl Colombia, Dept Internal Med, Bogota, ColombiaPontificia Univ Catolica Ecuador, Fac Med, Hosp Vozandes, Quito, EcuadorHosp Vargas de Caracas, Caracas, VenezuelaCtr Med Caracas, Caracas, VenezuelaUniv Chile, Fac Med, Dept Pediat, Hosp Luis Calvo Mackenna, Santiago 7, ChileUniv Desarrollo, Clin Alemana, Dept Med, Infect Dis Unit, Santiago, ChileInst Nacl Ciencias Med & Nutr Salvador Zubiran, Mexico City, DF, MexicoUniv Peruana Cayetano Heredia, Dept Med, Lima, PeruUniversidade Federal de São Paulo, Escola Paulista Med, Div Infect Dis, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Div Infect Dis, São Paulo, BrazilWeb of Scienc
- …