RESUMEN
BACKGROUND: Chagas disease (CD) is considered by the World Health Organisation (WHO) a neglected disease endemic to the Americas, but it has spread throughout the world due to migrations. The disease is almost 100% curable if detected in time. Still, the lack of rapid diagnostic tests with sufficient sensitivity and specificity leads to a chronic phase with a mortality of about 50,000 people worldwide per year. METHODS: Using the total proteins extracted from serum samples of patients confirmed with chronic phase CD; we performed the Bio-SELEX strategy. The best aptamers were selected using next-generation sequencing (NGS) based on their most abundant sequences (reads and rpm). Then, selected aptamers were used to isolate potential biomarkers directly from serum samples of patients with chronic phase CD using pull-down and mass spectrometry experiments. RESULTS: CH1 aptamer was the aptamer selected after the NGS results analysis. The pull-down and mass spectrometry experiments identified the presence of the ATPase alpha subunit of T. cruzi circulating in serum samples of patients with chronic phase CD. CONCLUSIONS: We report the ATPase alpha subunit of T. cruzi as a potential biomarker for chronic phase CD and CH1 aptamer as a potential tool for diagnosing CD.
Asunto(s)
Enfermedad de Chagas , Trypanosoma cruzi , Humanos , Trypanosoma cruzi/genética , Adenosina Trifosfatasas , Enfermedad de Chagas/diagnóstico , Sensibilidad y Especificidad , BiomarcadoresRESUMEN
Adsorption methods have been developed for the removal of arsenic from solution motivated by the adverse health effects of this naturally occurring element. Iron exchanged natural zeolites are promising materials for this application. In this study we introduced iron species into a clinoptilolite-rich zeolitic tuff by the liquid exchange method using different organic and inorganic iron salts after pretreatment with NaCl and quantified the iron content in all trials by XRF spectroscopy. The materials were characterized by XRD, FTIR, FTIR-DR, UV-vis, cyclic voltammetry, ESR and Mössbauer spectroscopies before and after adsorption of arsenite and arsenate. The reached iron load in the sample T+Fe was %Fe(2)O(3)-2.462, n(Fe)/n(Al)=0.19, n(Si)/n(Fe)=30.9 using FeCl(3), whereby the iron leachability was 0.1-0.2%. The introduced iron corresponded to four coordinated species with tetrahedral geometry, primarily low spin ferric iron adsorbing almost 12 mug g(-1) arsenite (99% removal) from a 360 mug(As(III)) L(-1) and 6 mug g(-1) arsenate from a 230 mug(As(V)) L(-1). Adsorption of arsenite and arsenate reached practically a plateau at n(Fe)/n(Si)=0.1 in the series of exchanged tuffs. The oxidation of arsenite to arsenate in the solution in contact with iron modified tuff during adsorption was observed by speciation. The reduction of ferric iron to ferrous iron could be detected in the electrochemical system comprising an iron-clinoptilolite impregnated electrode and was not observed in the dried tuff after adsorption.
RESUMEN
An NP-HPLC method both with diode-array (DAD) and electrochemical detection (ED) was developed and validated for the determination of quercetin and kaempferol, the principal active constituents in phytopharmaceuticals of Ginkgo Biloba. Calculated retention of the two flavonoids was contrasted with experimental values in five different reversed phase columns for methanol-water, acetonitrile-water, THF-water and dioxane-hexane binary mixtures as mobile phases. The capacity factor k, selectivity alpha and asymmetry factor F were evaluated and compared in DAD-RP-HPLC, DAD-NP-HPLC, ED-RP-HPLC and ED-NP-HPLC. The methods were used for the quantitative analysis of acid hydrolyzed extracts of tablet phytopharmaceuticals. Calibration curves were linear within the range 10 and 40 microg ml(-1) for the DAD and 10-270 microg ml(-1) for the ED, whereby limits of detection ranged from 0.5 microg ml(-1) (quercetin) to 0.1 microg ml(-1) (kaempferol). The electrochemical method based on differential pulse voltammetry (DPV) with a C-PVC electrode resolved the quercetin and kaempferol peaks and exhibited a two orders higher sensitivity in comparison with a carbon fiber electrode. DPV calibration curves were linear within the range 96-300 microg ml(-1) for quercetin and 68-960 microg ml(-1) for kaempferol. The respective oxidation peaks appeared at 462 and 518+/-2 mV and were used in the direct determination of quercetin in extracts of commercial phytopharmaceuticals.
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Cromatografía Líquida de Alta Presión/métodos , Electroquímica/métodos , Quempferoles/análisis , Extractos Vegetales/análisis , Quercetina/análisis , Estabilidad de Medicamentos , Ginkgo biloba/química , Preparaciones Farmacéuticas/análisis , Extractos Vegetales/química , Reproducibilidad de los Resultados , ComprimidosRESUMEN
Validation of a PCR test to detect hilA gene sequences of Salmonella spp. was performed in blood and faeces samples from typhoid fever and salmonellosis patients. Sensitivity (S), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) of the PCR in blood samples were performed by testing: 37 patients with clinical diagnosis of typhoid fever, 34 of them confirmed by isolation of S. Typhi from blood cultures; 35 patients infected with other pathogens corroborated by blood culture (Klebsiella pneumoniae, 9; Serratia marcescens, 5; Escherichia coli, 4; Pseudomonas aeruginosa, 9; Providencia alcalifaciens, 4 and Enterobacter cloacae, 4) and blood samples from 150 healthy volunteers. To evaluate S, SP, PPV and NPV of the PCR in faeces samples we studied: 34 patients with enteritis due Salmonella spp. (S. Typhimurium, 21; S. Enteritidis, 9; S. Choleraesuis, 3 and S. Agona, 1); faeces samples from 35 patients with enteric infection due to Shigella sonnei (8), Shigella flexneri (10), enteropathogenic E. coli (12), Aeromonas hydrophila (5) and faeces samples from 150 healthy volunteers. The S, SP, PPV and NPV of the PCR in blood samples were all 100 %. PCR detected three patients with clinical diagnosis of typhoid fever and negative blood cultures. In faeces samples, S was 97 %, SP 100 %, PPV 100 % and NPV 99 %. The lowest number of c.f.u. ml(-1) detected by PCR in blood samples was 1 x 10(1) and in faeces samples 4 x 10(2).
Asunto(s)
Reacción en Cadena de la Polimerasa/métodos , Infecciones por Salmonella/diagnóstico , Salmonella enterica/aislamiento & purificación , Salmonella typhi/aislamiento & purificación , Fiebre Tifoidea/diagnóstico , Proteínas Bacterianas , Sangre/microbiología , Colombia , Heces/microbiología , Humanos , Valor Predictivo de las Pruebas , Infecciones por Salmonella/microbiología , Salmonella enterica/genética , Salmonella typhi/genética , Sensibilidad y Especificidad , Transactivadores/genética , Fiebre Tifoidea/microbiologíaRESUMEN
Basic yellow 28 (SLY) and Reactive black 5 (CBWB), which are respectively methine and sulfoazo textile dyes were individually exposed to electrochemical treatment using diamond-, aluminium-, copper- and iron-zinc alloy electrodes. The generated current was registered with time during electrolysis of the dye solutions and the color variation and the formation of degradation products were followed using HPLC with diode array detection. Four different electrodic materials were tested by applying different potentials in the range -1.0 to -2.5 V and presented 95% color removal and COD removal of up to 65-67% in the case of CBWB dye solution treated with the copper and iron electrodes. Efficiency was enhanced with stirring and flow in relation to the stationary regime. The kinetic parameter reaction rate was used to establish the effect of flow, potential, electrode nature and pH. The formation and characterization of the precipitate formed under certain conditions is reported and discussed.
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Colorantes/química , Electroquímica/métodos , Naftalenosulfonatos/química , Contaminación Química del Agua/prevención & control , Aleaciones/química , Cromatografía Líquida de Alta Presión , Diamante/química , Electrodos , Concentración de Iones de Hidrógeno , Cinética , Industria TextilRESUMEN
The adsorption of Cd2+, Cr3+, Cu2+, Fe3+, Ni2+, Pb2+ and Zn2+ from aqueous solution was used to study the sorption properties of the adsorbent CACMM2 extracted from a cactus. Quantitation of the cation concentrations was performed by HPLC with diode array detection using on-column complex formation with 8-hydroxyquinoline. Removal degree from 100 mg M(n+) l(-1) solutions followed the series: Cu>Cd>Fe>Ni>Cr>Zn. Henry and Freundlich constants were determined since adsorption did not reach saturation plateaux in the studied concentration interval. Sorption of chromium by CACMM2 was stronger than the sorption onto lignin, calcium oxalate and cellulose up to 1,000 mg Cr3+ l(-1). Copper and iron were desorbed to a greater extent, while lead adsorption was practically irreversible. CACMM2 was able to remove more than 83% of chromate in a freshly prepared and exhausted chromate commercial solution.
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Metales/aislamiento & purificación , Adsorción , Cationes , Cromatografía Líquida de Alta Presión , Soluciones , Agua/químicaRESUMEN
Several textile dyes were individually exposed to electrochemical treatment. Chromaticity variation and the formation of degradation products were followed using a UV spectrophotometer and HPLC with diode array detection. Dyes studied belong to the azo (color index, C.I. 15,510), methine (C.I. 48,013), indigo (C.I. 73,040), natural (C.I. 75,760) and arylmethane (C.I. 42,000) classes. Aliquots of the solutions treated at constant potential were analyzed and compared with control dye solutions. The final electrolysis solutions obtained by using different electrode materials: Pt, Ti and diamond presented different chromatograms. It was found that the novel (in this application) diamond electrode is efficient in studying the degradation of various dyes. Possible fragmentation and molecule moiety rearrangement are proposed as a result of the electrochemical treatment.