69 research outputs found

    Mortality and Advanced Support Requirement for Patients With Cancer With COVID-19 : A Mathematical Dynamic Model for Latin America

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    PURPOSE: In the midst of a global pandemic, evidence suggests that similar to other severe respiratory viral infections, patients with cancer are at higher risk of becoming infected by COVID-19 and have a poorer prognosis. METHODS: We have modeled the mortality and the intensive care unit (ICU) requirement for the care of patients with cancer infected with COVID-19 in Latin America. A dynamic multistate Markov model was constructed. Transition probabilities were estimated on the basis of published reports for cumulative probability of complications. Basic reproductive number (R0) values were modeled with R using the EpiEstim package. Estimations of days of ICU requirement and absolute mortality were calculated by imputing number of cumulative cases in the Markov model. RESULTS: Estimated median time of ICU requirement was 12.7 days, median time to mortality was 16.3 days after infection, and median time to severe event was 8.1 days. Peak ICU occupancy for patients with cancer was calculated at 16 days after infection. Deterministic sensitivity analysis revealed an interval for mortality between 18.5% and 30.4%. With the actual incidence tendency, Latin America would be expected to lose approximately 111,725 patients with cancer to SARS-CoV-2 (range, 87,116-143,154 patients) by the 60th day since the start of the outbreak. Losses calculated vary between < 1% to 17.6% of all patients with cancer in the region. CONCLUSION: Cancer-related cases and deaths attributable to SARS-CoV-2 will put a great strain on health care systems in Latin America. Early implementation of interventions on the basis of data given by disease modeling could mitigate both infections and deaths among patients with cancer

    Variability of the air temperature and its comparison with MODIS Land Surface Temperature in the Hurd Peninsula of the Livingston Island, Antarctica, between 2000 and 2016

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    Ponencia presentada en: XVIII Congreso de la Asociación Española de Teledetección celebrado en Valladolid del 24 al 27 septiembre 2019.[ES]En los ambientes polares, tan vulnerables al cambio climático, el estudio de la temperatura es imprescindible. Por ello, y en el marco del proyecto PERMASNOW, en este trabajo hemos estudiado en detalle la variación de la temperatura del aire (Ta) en la península Hurd de la isla Livingston (Antártida) y hemos tratado de estimarla a partir de los datos de temperatura de la superficie terrestre (LST, por sus siglas en inglés) del sensor MODIS entre los años 2000 y 2016. Utilizamos datos de Ta media diaria obtenidos en seis puntos, tres estaciones meteorológicas de AEMET y tres estaciones del proyecto PERMASNOW: Juan Carlos I (JCI), Glaciar Johnson (GJ), Glaciar Hurd (GH), Incinerador (INC), Reina Sofía (RS) y Collado Ramos (CR), respectivamente. Los datos MODIS LST son los diurnos y nocturnos de los satélites Terra y Aqua. La tendencia en Ta se ha analizado mediante la regresión localmente ponderada (LOESS, por sus siglas en inglés) y la relación Ta -LST con regresiones lineales múltiples. Concluimos que Ta en el área de estudio varía: se observa en la estación JCI, más cercana a la costa, una tendencia al enfriamiento con valores entre –2,3 y –3,0°C década–1. En cambio, las estaciones más alejadas de la costa y de mayor altitud muestran una tendencia al calentamiento (entre +0,2 y +0,8°C década-1). Los mejores modelos de estimación de Ta a partir de LST y variables temporales se obtienen con los datos diurnos de Terra (R2 = 0,5-0,7; RSE = 2°C), exceptuando GJ, donde la variable LST no es significativa. Con la validación cruzada (CV) se aprecian también, excepto en GJ, mejores resultados con los datos diurnos de Terra (R2 CV = 0,5-0,6; RMSECV = 2,5-2,6°C). Finalmente, concluimos que los datos MODIS LST son útiles para estimar tendencias de Ta a largo plazo en el área de estudio.[EN]In polar zones, where satellite data are very useful due to the limited in situ data, it is therefore essential to study the air temperature behaviour. In the framework of the PERMASNOW project we estimated the air temperature (Ta) in the Hurd Peninsula of Livingston Island (Antarctica) from the land surface temperature (LST) data of the MODIS between 2000 and 2016. We worked with Ta data obtained at six stations (3 AEMET meteorological stations and 3 PERMASNOW project stations: Juan Carlos I (JCI), Johnson Glacier (JG), Hurd Glacier (HG), Incinerator (INC), Reina Sofia (RS) and Collado Ramos (CR), respectively. In addition, we analyzed daytime and nighttime LST data from the Terra and Aqua satellites. Locally weighted regression (LOESS) and multiple linear regressions were used for statistical analysis. We conclude that the Ta in the study area varies: a cooling trend with values between –2.3 and –3.0°C decade-1 is observed in JCI, which is closer to the coast. On the other hand, the stations farther from the coast and at higher altitudes show a warming trend (between +0.2 and +0.8°C decade-1). The best Ta models are obtained with Terra daytime data (R2 = 0.5-0.7 and RSE = 2°C), except JG, where the LST variable is not significant. With cross validation (CV), better results are also seen, except in JG, with the daytime Terra data (R2 CV = 0.5-0.6, RMSECV = 2.5-2.6°C). In summary, MODIS LST data are useful for estimating long-term Ta trends in the study area.Esta investigación fue posible gracias a la financiación de la Agencia Estatal de Investigación a través del proyecto PERMASNOW [CTM2014-52021-R], la ayuda de la Universidad de Oviedo al Grupo de Investigación RSApps en 2018 [PAPI-18-GR-2016-0005] y las ayudas obtenidas por A.C.-P. (“Severo Ochoa” del Gobierno del Principado de Asturias [BP17-151] y “Ayuda Predoctoral” de la Universidad de Oviedo)

    A phase II study of docetaxel in patients with metastatic squamous cell carcinoma of the head and neck

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    This study was designed to evaluate the activity, safety and tolerance of docetaxel (D) in a selected population with metastatic squamous cell carcinoma of the head and neck (SCCHN). Twenty-four patients with no prior palliative therapy were enrolled and received D 100 mg m−2 by 1 h of infusion, every 3 weeks. All but two patients had been evaluated for efficacy on lung metastatic sites. No prophylactic administration of anti-emetics or growth factors was given. A pharmacokinetic study was performed in 22 patients. Twenty-one patients were assessable for response and 24 for toxicity. One hundred and four cycles were administered with a median of 4.5 (range 1–9) per patient. The median cumulative dose was 449 mg m−2. Partial responses were achieved in five patients with a median duration of 18.7 weeks (range 13.1–50.3). The overall response rate was 20.8% with a median duration of 11.0 weeks (range 2.4–52.6). The most frequent side-effect was neutropenia (79.2% grade IV) but with a short duration (median 4 days) and no febrile neutropenia. The incidence of moderate/severe fluid retention was 29.2% with one treatment discontinuation. Other toxicities (all grades) were common (skin 75%, asthenia 50%, infection 29.2%, nausea 16.7%, diarrhoea 12.5%, stomatitis 16.7%, vomiting 8.3% and HSR 8.3%). A mean clearance of 19.6 l h−1 m−2 and an area under the curve of 6.00 μg ml−1 h−1 was found in the pharmacokinetic analysis. Docetaxel is active in this selected population with metastatic SCCHN, with a good tolerance. © 1999 Cancer Research Campaig

    Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. VI. Variability of NGC 3783 from ground-based data

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    The Seyfert 1 galaxy NGC 3783 was intensely monitored between 1991 December and 1992 August. We present the results from the ground-based observations in the optical and near-IR, which complement the data-set from the IUE, discussed elsewhere. Spectroscopic and photometric data from many observatories were combined in order to obtain well sampled light curves of the continuum and of H-Beta. During the campaign the source varied significantly. The light curves of the optical continuum and of H-Beta are similar to those obtained with the IUE. The near-IR flux did not vary significantly except for an increase at the end of the campaign. The optical continuum and the flux of H-Beta lag the UV continuum by 1 day or less and by 8 days respectively. These results confirm that the continuum variations are simultaneous or have a very small lag across the entire UV-optical range, and that the lines of NGC 3783 respond to ionizing continuum variations with less delay than those of NGC 5548. As in NGC 5548, the lag of H-Beta is greater than those of the high ionization lines.Comment: 34 pages in LaTeX, 7 postscript figures available on request from [email protected] or 37907::stirpe, BAP#10-1993-035-OA

    Multiwavelength observations of short time-scale variability in NGC 4151. I. Ultraviolet observations

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    We present the results of an intensive ultraviolet monitoring campaign on the Seyfert 1 galaxy NGC 4151, as part of an effort to study its short time-scale variability over a broad range in wavelength. The nucleus of NGC 4151 was observed continuously with the {\it International Ultraviolet Explorer} (IUE) for 9.3 days, yielding a pair of LWP and SWP spectra every \sim70 minutes, and during four-hour periods for 4 days prior to and 5 days after the continuous monitoring period. The sampling frequency of the observations is an order of magnitude higher than that of any previous UV monitoring campaign on a Seyfert galaxy. The continuum fluxes in bands from 1275 \AA\ to 2688 \AA\ went through four significant and well-defined ``events'' of duration 2 -- 3 days during the continuous monitoring period. We find that the amplitudes of the continuum variations decrease with increasing wavelength, which extends a general trend for this and other Seyfert galaxies to smaller time scales (i.e., a few days). The continuum variations in all of the UV bands are {\it simultaneous} to within an accuracy of about 0.15 days, providing a strict constraint on continuum models. The emission-line light curves show only one major event during the continuous monitoring (a slow rise followed by a shallow dip), and do not correlate well with continuum light curves over the (short) duration of the campaign, because the time scale for continuum variations is apparently smaller than the response times of the emission lines.Comment: 39 pages, LaTeX, including 7 PostScript figures; To appear in the ApJ (October 20, 1996) Vol. 47

    Multiwavelength observations of short time-scale variability in NGC 4151. IV. Analysis of multiwavelength continuum variability

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    This paper combines data from the three preceding papers in order to analyze the multi-waveband variability and spectral energy distribution of the Seyfert~1 galaxy NGC~4151 during the December 1993 monitoring campaign. The source, which was near its peak historical brightness, showed strong, correlated variability at X-ray, ultraviolet, and optical wavelengths. The strongest variations were seen in medium energy (\sim1.5~keV) X-rays, with a normalized variability amplitude (NVA) of 24\%. Weaker (NVA = 6\%) variations (uncorrelated with those at lower energies) were seen at soft γ\gamma-ray energies of \sim100~keV. No significant variability was seen in softer (0.1--1~keV) X-ray bands. In the ultraviolet/optical regime, the NVA decreased from 9\% to 1\% as the wavelength increased from 1275~\AA\ to 6900~\AA. These data do not probe extreme ultraviolet (1200~\AA\ to 0.1~keV) or hard X-ray (2--50~keV) variability. The phase differences between variations in different bands were consistent with zero lag, with upper limits of \ls0.15~day between 1275~\AA\ and the other ultraviolet bands, \ls0.3~day between 1275~\AA\ and 1.5~keV, and \ls1~day between 1275~\AA\ and 5125~\AA. These tight limits represent more than an order of magnitude improvement over those determined in previous multi-waveband AGN monitoring campaigns. The ultraviolet fluctuation power spectra showed no evidence for periodicity, but were instead well-fitted with a very steep, red power-law (a=2.5 a = -2.5 ). If photons emitted at a ``primary" waveband are absorbed by nearby material and ``reprocessed" to produce emission at a secondary waveband, causality arguments require that variations in the secondary band follow those in the primary band. The tight interband correlation and limits on the ultraviolet andComment: 35 pages, LaTeX (including aaspp4), including 7 PostScript figures; To appear in the ApJ (October 20, 1996) Vol. 47

    Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 5: Variability of the ultraviolet continuum and emission lines of NGC 3783

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    We report on the results of intensive ultraviolet spectral monitoring of the Seyfert 1 galaxy NGC 3783. The nucleus of NGC 3783 was observed with the International Ultraviolet Explorer satellite on a regular basis for a total of 7 months, once every 4 days for the first 172 days and once every other day for the final 50 days. Significant variability was observed in both continuum and emission-line fluxes. The light curves for the continuum fluxes exhibited two well-defined local minima or 'dips,' the first lasting is less than or approximately 20 days and the second is less than or approximately 4 days, with additional episodes of relatively rapid flickering of approximately the same amplitude. As in the case of NGC 5548 (the only other Seyfert galaxy that has been the subject of such an intensive, sustained monitoring effort), the largest continuum variations were seen at the shortest wavelengths, so that the continuum became 'harder' when brighter. The variations in the continuum occurred simultaneously at all wavelengths (delta(t) is less than 2 days). Generally, the amplitude of variability of the emission lines was lower than (or comparable to) that of the continuum. Apart from Mg II (which varied little) and N V (which is relatively weak and badly blended with Ly(alpha), the light curves of the emission lines are very similar to the continuum light curves, in each case with a small systematic delay or 'lag.' As for NGC 5548, the highest ionization lines seem to respond with shorter lags than the lower ionization lines. The lags found for NGC 3783 are considerably shorter than those obtained for NGC 5548, with values of (formally) approximately 0 days for He II + O III), and approximately 4 days for Ly(alpha) and C IV. The data further suggest lags of approximately 4 days for Si IV + O IV) and 8-30 days for Si III + C III). Mg II lagged the 1460 A continuum by approximately 9 days, although this result depends on the method of measuring the line flux and may in fact be due to variability of the underlying Fe II lines. Correlation analysis further shows that the power density spectrum contains substantial unresolved power over timescales of is less than or approximately 2 days, and that the character of the continuum variability may change with time

    A small fraction of dermatan sulfate with significantly increased anticoagulant activity was selected by interaction with the first complement protein

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    Dermatan sulfate (DS) is a member of the family of structurally complex, sulfated, linear heteropolysaccharides called glycosaminoglycans (GAGs). It has a similar structure to heparin and heparan sulfate (HS), but with acetylgalactosamine replacing glucosamine, and the uronic acid moiety, mainly iduronic, joined 1→3 to the hexosamine. We are studying the relationships between structure and activities of dermatan sulfate, in particular those associated with the thrombin inhibition mediated by heparin cofactor II (HCII). As we have demonstrated with heparin, a small fraction of dermatan sulfate was isolated by precipitation with the first component of the complement system, under very specific conditions of low ionic strength, and the presence of calcium ions. The sulfate content and the anticoagulant activity of the dermatan sulfate fraction isolated in the precipitate were three and four times greater respectively than the starting material. Our in vivo studies showed that this fraction has threefold higher thrombolytic activity than the DS. All these results suggest that this fraction could be used as a therapeutic agent for thrombi dissolution. © 2004 Elsevier Ltd. All rights reserved.Fil: Calabrese, Graciela Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; ArgentinaFil: Alberto, Maria Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Tubio, Maria Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; ArgentinaFil: Marani, Mariela Mirta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; ArgentinaFil: Fernández De Recondo, Marta E.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas; ArgentinaFil: Lazzari, María Ángela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Recondo, Eduardo F.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentin
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