Surveillance of Candida spp Bloodstream Infections: Epidemiological Trends and Risk Factors of Death in Two Mexican Tertiary Care Hospitals

Introduction: Larger populations at risk, broader use of antibiotics and longer hospital stays have impacted on the incidence of Candida sp. bloodstream infections (CBSI).Objective: To determine clinical and epidemiologic characteristics of patients with CBSI in two tertiary care reference medical institutions in Mexico City.Design: Prospective and observational laboratory-based surveillance study conducted from 07/2008 to 06/2010.Methods: All patients with CBSI were included. Identification and antifungal susceptibility were performed using CLSI M27-A3 standard procedures. Frequencies, Mann-Whitney U test or T test were used as needed. Risk factors were determined with multivariable analysis and binary logistic regression analysis.Results: CBSI represented 3.8% of nosocomial bloodstream infections. Cumulative incidence was 2.8 per 1000 discharges (incidence rate: 0.38 per 1000 patient-days). C. albicans was the predominant species (46%), followed by C. tropicalis (26%). C. glabrata was isolated from patients with diabetes (50%), and elderly patients. Sixty-four patients (86%) received antifungals. Amphotericin-B deoxycholate (AmBD) was the most commonly used agent (66%). Overall mortality rate reached 46%, and risk factors for death were APACHE II score >= 16 (OR = 6.94, CI95% = 2.34-20.58, p<0.0001), and liver disease (OR = 186.11, CI95% = 7.61-4550.20, p = 0.001). Full susceptibility to fluconazole, AmBD and echinocandins among C. albicans, C. tropicalis, and C. parapsilosis was observed.Conclusions: the cumulative incidence rate in these centers was higher than other reports from tertiary care hospitals from Latin America. Knowledge of local epidemiologic patterns permits the design of more specific strategies for prevention and preemptive therapy of CBSI.Pfizer Inc.Salvador Zubiran Natl Inst Med Sci & Nutr, Dept Med, Mexico City, DF, MexicoHosp Escuela Tegucigalpa, Tegucigalpa, HondurasUniversidade Federal de São Paulo, Escola Paulista Med, Div Infect Dis, São Paulo, BrazilNatl Canc Inst, Div Infect Dis, Mexico City, DF, MexicoUniv Nacl Colombia, Dept Internal Med, Bogota, ColombiaUniv Peruana Cayetano Heredia, Dept Med, Lima, PeruHosp Vargas Caracas, Caracas, VenezuelaCtr Med Caracas, Caracas, VenezuelaUniv Fed Rio de Janeiro, Univ Hosp, Rio de Janeiro, BrazilUniv Texas Med Sch Houston, Mem Hermann Texas Med Ctr, Dept Med, Houston, TX USAUniv Fed Parana, Hosp Clin, BR-80060000 Curitiba, Parana, BrazilUniv Chile, Fac Med, Hosp Luis Calvo Mackenna, Dept Pediat, Santiago 7, ChileUniv Desarrollo, Clin Alemana, Dept Med, Santiago, ChileHosp Clin Jose San Martin, Infect Dis Unit, Buenos Aires, DF, ArgentinaPontificia Univ Catolica Ecuador, Fac Med, Hosp Vozandes, Quito, EcuadorUniversidade Federal de São Paulo, Escola Paulista Med, Div Infect Dis, São Paulo, BrazilPfizer Inc.: INF-168Web of Scienc

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Pre-concentration of rare earths using silica gel loaded with 1-(2-pyridylazo)-2-naphthol (PAN) and determination by energy dispersive X-ray fluorescence

The determination of a single rare earth element in a mixture with other species of this family is a very challenging problem in analytical chemistry due to the close similarity of their chemical properties. In this work, a liquid-solid extraction procedure for praseodymium, neodymium, samarium and yttrium mixtures and subsequent determination by energy dispersive X-ray fluorescence spectrometry is described. The pre-concentration procedure, which involves the use of silica modified with 1-(2-pyridyrazo)-2-naphthol, permits complete recovery of the ran earths and significant sensitivity enhancement in comparison with direct determination in the aqueous phase. Determinations in quaternary mixtures show typical precisions and accuracies of 3% and 5%, respectively. (C) 1998 Elsevier Science B.V. All rights reserved.4661371137

Determination of some rare earth elements by EDXRF and artificial neural networks

This paper describes the simultaneous determination of Pr, Nd and Sm by EDXRF spectrometry using mixtures of oxides of these metals in a silica matrix. The data were treated by distinct neural network algorithms: back-propagation (BP), Levenberg-Marquardt (LM) and two variations of back-propagation (called BP-SC, single component, and BP-MC, multiple component), using results from the PLS model (partial least square regression) for comparison. The best applied model was the BP-SC neural network, which produced relative standard errors of prediction of 17.5% for Pr, 12.5% for Nd and 12.6% for Sm. Copyright (C) 2003 John Wiley Sons, Ltd.32642342

Chemometric Alternatives For Resolution Of Classical Analytical Problems: Spectrophotometric Determination Of Lanthanide Mixtures

The simultaneous determination of lanthanide family elements is one of the greatest problems in analytical chemistry, due to the close similarity of their chemical properties. Spectrophotometric methods are generally of limited use, due to the various mutual spectral interferences involved. By using multivariate calibration methods (partial least-squares regression, PLSR), it was possible to obtain a model that adjusts itself perfectly to the values of the mixture concentrations used in the calibration. The model used absorption spectra in the 290-800 nm range for a set of 20 different mixtures of Ce, Pr, Nd and Sm, and made possible the determination of Ce, Pr and Nd concentrations of a commercial rare-earth product, with significantly greater precision than the conventional univariate calibration method. Determination of the Sm concentrations was not possible, since its concentration was below the concentrations used in the model definition.441018151822Moeller, T., (1976) The Chemistry of the Lanthanides, Pergamon Texts in Inorganic Chemistry, 26, p. 1Barbieri, Z.L., (1982) Anais do VI Simpósio Anual da ACIESP, 1, p. 110Fassel, V.A., Curry, R.H., Kniseley, R.N., (1962) Spectrochim. Acta, 18, p. 1127Vickery, R.C., (1961) Analytica Chemistry of the Rare Earths, , Pergamon Press, OxfordLajunen, L.H.J., Choppin, G.R., (1989) Rev. Anal. Chem., 9, p. 3Gao, J., He, J., Wane, X., Wane, Z., Bai, E., (1987) Analyst, 112, p. 1081Heidel, R.H., Fassel, V.A., (1958) Anal. Chem., 30, p. 176Jackson, W.M., Gleason, G.I., Hammons, P.J., (1970) Anal. Chem., 42, p. 1243Jackson, W.M., Gleason, G.I., (1973) Anal. Chem., 45, p. 2125Robards, K., Clarke, S., Patsalides, E., (1988) Analyst, 113, p. 1757D'Silva, A.P., Kniseley, R.N., Fassel, V.A., Curry, R.H., Myers, R.B., (1964) Anal. Chem., 36, p. 532Fassel, V.A., Curry, R.H., Kniseley, R.N., (1962) Spectrochim. Acta, 18, p. 1127Bhattacharya, S., Lyle, S., Maghzian, R., (1980) R. Talanta, 27, p. 59Lyle, S.J., Zatar, N.A., (1982) Anal. Chim. Acta., 135, p. 327Poluektov, N.S., Sandu, M.A.J., (1970) J. Anal. Chem. USSR, 25, p. 1302Spitsyn, P.K., Shvarev, V.S.J., (1970) J. Anal. Chem. USSR, 25, p. 1297Banks, C.V., Klisgman, D.W., (1956) Anal. Chim. Acta, 15, p. 356Stewart, D.C., Kato, D., (1958) Anal. Chem., 30, p. 164Martens, H., Naes, T., (1993) Multivariate Calibration, , Wiley, ChichesterSalinas, F., Espinosa-Mansilla, A., Lopez De Alba, P.L., (1995) Anal. Lett., 28, p. 193Lyle, S.J., Rahman, M., (1963) Talanta, 10, p. 1177Wise, B.M., Gallagher, (1995) PLS - Toolbox for use with Matlab, Version 1.5.

Determination of manganese by flame atomic absorption spectrometry after its adsorption onto naphthalene modified with 1-(2-pyridylazo)-2-naphthol (PAN)

A system for determination of manganese, after preconcentration with 3% (w/w) 1-(2-pyridylazo)-2-naphthol (PAN), adsorbed on microcrystalline naphthalene is proposed. An amount of 200 mg of this complexing mixture is placed in a glass column and conditioned with a NH4Cl/NH4OH buffer solution (pH 9.5). The aqueous sample, containing manganese, is treated with an ammonium tartrate solution, then with a hydroxylammonium chloride solution and, finally, with a buffer solution. The resulting solution is passed through the column containing microcrystalline naphthalene modified with 1-(2-pyridylazo)-2-naphthol (PAN) where Mn(II) is retained. The column is first washed with deionized water and then with 10.0 ml of dimethylformamide to dissolve the Mn(II)-PAN/naphthalene complex. Manganese is determined by air-acetylene flame atomic absorption spectrometry. About 1 mu g of manganese can be concentrated from 200 ml of aqueous sample, allowing a preconcentration factor of 20, a limit of quantification of 5 ng ml(-1) and R.S.D. of 3.8%. The accuracy was ascertained using certified reference materials, including samples of urine and glass. Water samples were also analysed and the results are in good agreement with those obtained by graphite furnace atomic absorption spectrometry. (c) 2006 Elsevier B.V. All rights reserved.7131252125

Pre-concentration Of Rare Earths Using Silica Gel Loaded With 1-(2-pyridylazo)-2-naphthol (pan) And Determination By Energy Dispersive X-ray Fluorescence.

The determination of a single rare earth element in a mixture with other species of this family is a very challenging problem in analytical chemistry due to the close similarity of their chemical properties. In this work, a liquid-solid extraction procedure for praseodymium, neodymium, samarium and yttrium mixtures and subsequent determination by energy dispersive X-ray fluorescence spectrometry is described. The pre-concentration procedure, which involves the use of silica modified with 1-(2-pyridylazo)-2-naphthol, permits complete recovery of the rare earths and significant sensitivity enhancement in comparison with direct determination in the aqueous phase. Determinations in quaternary mixtures show typical precisions and accuracies of 3% and 5%, respectively.461371-

Zirconium And Hafnium Determination By Energy Dispersive X-ray Fluorescence With Solid Phase Preconcentration.

Two preconcentration methods has been developed for simultaneous determination of zirconium and hafnium by energy dispersive X-ray fluorescence (EDXRF). The first method is a liquid-solid extraction procedure with the use of an anionic exchange resin modified with xylenol orange. The second is a precipitation procedure carried out in the presence of lanthanum. Both methods permit significant enhancement of sensitivity in comparison with direct measurement in the aqueous phase. The applicability of both procedures for the preconcentration of Zr and Hf prior to their determination by EDXRF was demonstrated by analyzing synthetic mixtures and a sample of zirconium ore. The results obtained with the use of the modified resin show relative standard deviation of about 4% and good agreement with those obtained by spectrographic analysis.44811-