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1.
J Biomed Biotechnol ; 2011: 158094, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-20886062

RESUMEN

We report the successful classification, by artificial neural networks (ANNs), of (1)H NMR spectroscopic data recorded on whole-cell culture samples of four different lung carcinoma cell lines, which display different drug resistance patterns. The robustness of the approach was demonstrated by its ability to classify the cell line correctly in 100% of cases, despite the demonstrated presence of operator-induced sources of variation, and irrespective of which spectra are used for training and for validation. The study demonstrates the potential of ANN for lung carcinoma classification in realistic situations.


Asunto(s)
Células/clasificación , Espectroscopía de Resonancia Magnética/métodos , Metabolómica/métodos , Redes Neurales de la Computación , Línea Celular , Humanos , Análisis de Componente Principal , Reproducibilidad de los Resultados
2.
Bull Entomol Res ; 101(2): 165-75, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20961466

RESUMEN

Artificial neural networks (ANN) methodology, molecular analyses and comparative morphology of the male postabdomen were used successfully in parallel for species identification and resolution of some taxonomic problems concerning West Palaearctic species of the genus Tachina Meigen, 1803. Supervised feed-forward ANN with back-propagation of errors was applied on morphometric and qualitative characters to solve known taxonomic discrepancies. Background molecular analyses based on mitochondrial markers CO I, Cyt b, 12S and 16S rDNA and study of male postabdominal structures were published separately. All three approaches resolved taxonomic doubts with identical results in the following five cases: case 1, the four presently recognized subgenera of the genus Tachina were confirmed and the description of a new subgenus was recommended; case 2, the validity of a new boreo-alpine species (sp.n.) was confirmed; case 3, the previously supposed presence of T. casta (Rondani, 1859) in central Europe was not supported; case 4, West Palaearctic T. nupta (Rondani, 1859) was contrasted with East Palaearctic specimens from Japan, which seem to represent a valid species not conspecific with central European specimens; T. nupta needs detailed further study; case 5, T. nigrohirta (Stein, 1924) resurrected recently from synonymy with T. ursina Meigen, 1824 was confirmed as a valid species. This parallel application of three alternative methods has enabled the principle of 'polyphasic taxonomy' to be tested and verified using these separate results. For the first time, the value of using the ANN approach in taxonomy was justified by two non-mathematical methods (molecular and morphological).


Asunto(s)
ADN Mitocondrial/genética , Dípteros/clasificación , Redes Neurales de la Computación , Anatomía Comparada , Animales , Grupo Citocromo b/genética , Dípteros/anatomía & histología , Dípteros/genética , Europa (Continente) , Genes de Insecto , Masculino , Datos de Secuencia Molecular , ARN Ribosómico/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Especificidad de la Especie
3.
Heliyon ; 7(12): e08524, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34934840

RESUMEN

A new Cotton@Fe-BTC composite formed by Fe-BTC (BTC-H3: trimesic acid) metal framework (Fe-BTC MOF loading as high 38 wt %) supported by cellulose fiber is synthesized in aqueous media using a simple and green preparation method, described for the first time in this manuscript. This new strategy relies on the synergetic effect of the pure cellulose and MOFs frameworks resulting in hybrid nanofibers of MOFs@cellulose composite. A complete characterization of the composite material reveals its structural similarity to MIL-100(Fe), a Fe-BTC material. The Cotton@Fe-BTC composite potential use as an eco-friendly and low-cost adsorbent was evaluated for its adsorptive performance for the removal of dye belonging to the triarylmethane dye family (Malachite Green (MQ), Brilliant Green (BG), Pararosaniline (PR), Basic Fuchsine (BF), Crystal Violet (CV), Methyl Green (Met-G), Victoria Blue B (VB), Acid Fuchsin (AF) and Aniline Blue (AB)) in aqueous solution. The fast kinetics and high dye removal efficiencies (>90%) obtained in aqueous solutions. The structure of Cotton@Fe-BTC network, contributed to the remarkable adsorption properties towards a variety of triphenylmethanedye. The interparticle studies showed two main steps in the dye adsorption processes, with the exception of AF and BG. The equilibrium adsorption capacities qe (mg/g) follow the order: AF (3.64)

4.
J Vet Pharmacol Ther ; 33(1): 76-83, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20444029

RESUMEN

Chlortetracycline HCl (CTC) has impacted profitable livestock production since 1945. However, pharmacokinetic parameters for CTC in ruminating cattle are unavailable in peer-reviewed literature. A total of 18 steers were randomized to 4.4, 11, or 22 mg/kg/day p.o. CTC treatment groups (n = 6). Chlortetracycline treatment was offered as one-half of the daily dose b.i.d. (160 total doses/group) for 80 days. Blood samples were collected at selected time points throughout an 83-day study and analyzed with a solid phase extraction technique and novel ultrahigh performance liquid chromatography-mass spectroscopy/mass spectroscopy analytical method. Noncompartmental analysis (NCA) determined individual pharmacokinetic parameters by treatment group with coefficient of variation (CV %) estimates. A one-compartment open model with first order absorption and elimination, where absorption rate constant was equal to elimination rate constant, was fitted using nonlinear mixed effects modeling (NLMEM). NLMEM determined the primary pharmacokinetic parameters: volume of distribution (V/F, 40.9 L/kg) and rate constant (k, 0.0478 h(-1)), and the secondary parameters: dose-normalized area under the curve (AUC/D, 0.29 h x microg/L), clearance (Cl/F, 1.8 L/kg/h), elimination half-life (t(1/2), 16.2 h), C(max/Dose) (4.5 ng/mL), and time of C(max) (T(max), 23.3 h) with improved CV estimates over NCA. Dose linearity was confirmed by anova of parameters derived from NCA by treatment group. Further studies are necessary for determining absolute bioavailability and pharmacokinetic-pharmacodynamic relationships of CTC in group fed, ruminating cattle.


Asunto(s)
Crianza de Animales Domésticos , Antibacterianos/farmacocinética , Bovinos/sangre , Bovinos/metabolismo , Clortetraciclina/farmacocinética , Administración Oral , Animales , Antibacterianos/administración & dosificación , Antibacterianos/sangre , Área Bajo la Curva , Clortetraciclina/administración & dosificación , Clortetraciclina/sangre , Relación Dosis-Respuesta a Droga , Semivida , Masculino
5.
Talanta ; 207: 120275, 2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-31594592

RESUMEN

The magnetic metal-organic framework Fe3O4@(Fe-(benzene-1,3,5-tricarboxylic acid) (MMOF) was prepared, characterized and studied as a magnetic sorbent for the dispersive solid-phase extraction (DSPE) of several widely used blood lipid regulators (i.e., bezafibrate, clofibric acid, clofibrate, gemfibrozil and fenofibrate) from water samples. Characterization of the synthesized Fe3O4@Fe-BTC magnetic nanomaterial was performed by Fourier transform infrared spectroscopy, powder X-ray diffractometry, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. The magnetic nanocomposite was found to be chemically stable and to possess a large surface area (803.62 m2/g) and pore volume (0.59 cm³/g). The concentrations of fibrates in different water samples were determined using HPLC-UV-Vis and confirmed by UPLC-MS/MS. Parameters affecting the extraction efficiency of magnetic-DSPE were studied and optimized. The maxima absorption capacities (Qmax) were determined to be (in mg/g) 197.0 for bezafibrate, 620.3 for clofibric acid, 537.6 for clofibrate, 288.7 gemfibrozil and 223.2 for fenofibrate. Validations of the optimized magnetic DSPE method for analyses at two fibrate concentrations in spiked water samples produced relative recovery values ≤ 70% for clofibrate and within the range of 80-100% for bezafibrate, clofibric acid, gemfibrozil and fenofibrate. LODs ranging from 4 µg/L for fenofibrate to 99 µg/L for gemfibrozil were obtained. The validated methodology produced recovery values ranging from 70 to 112% (relative standard deviations < 7%).


Asunto(s)
Benceno/química , Hierro/química , Reguladores del Metabolismo de Lípidos/aislamiento & purificación , Estructuras Metalorgánicas/química , Extracción en Fase Sólida/métodos , Ácidos Tricarboxílicos/química , Agua/química , Reguladores del Metabolismo de Lípidos/sangre , Nanopartículas de Magnetita/química , Contaminantes Químicos del Agua/aislamiento & purificación
6.
J Clin Invest ; 57(2): 329-40, 1976 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-176179

RESUMEN

Splanchnic metabolism was studied to quantify changes underlying the fatty liver, hyperlipemia, and hypoglycemia produced by ethanol. Four subjects fasted for 15 h were compared with five subjects fasted for 69 h under basal conditions and during continuous intravenous infusion of sufficient ethanol to give a concentration of 3-5 mM in arterial blood plasma. Splanchnic storage of fatty acids was estimated from the difference between uptake of FFA and secretion of derived products. Basal values for splanchnic uptake of FFA were twofold higher after the 69-h fast while splanchnic storage of fatty acids and production of ketone bodies increased threefold. Values for basal secreation into the blood of triglycerides derived from FFA were similar in the two groups. In both nutritional states, the fraction of FFA taken up in the splanchnic region oxidized to ketone bodies and to CO2 fell when ethanol was given because of preferential oxidation of ethanol to acetate, and the fraction esterified rose. However, systemic transport and splanchnic uptake of FFA fell with ethanol in subjects fasted 15 h, so that neither storage of triglycerides in splanchnic tissues nor secretion into the blood increased. In subjects fasted 69 h, ethanol increased transport of FFA and splanchnic storage of fat. In all but one subject it also increased secretion of triglycerides into the blood. The concentration of glucose in blood fell during ethanol infusion in all five subjects undergoing the 69-h fast. Mean splanchnic glucose production was maintained at about one-half of the pre-ethanol value, despite virtual cessation of splanchnic uptake of lactate and of those amino acids that are metabolized via malate. Quantitative estimates of extrasplanchnic metabolism suggest that enhanced formation of alpha-glycerophosphate from glucose, in addition to impaired hepatic gluconeogenesis, may contribute to ethanol-induced hypoglycemia in man.


Asunto(s)
Abdomen/irrigación sanguínea , Aminoácidos/sangre , Carbohidratos/sangre , Etanol/farmacología , Ayuno , Acetoacetatos/sangre , Adulto , Glucemia/análisis , Humanos , Hidroxibutiratos/sangre , Cetonas/sangre , Lactatos/sangre , Lipoproteínas VLDL/sangre , Masculino , Oxígeno/metabolismo , Piruvatos/sangre , Triglicéridos/sangre
7.
Oncogenesis ; 6(9): e381, 2017 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-28945219

RESUMEN

PRAS40 has been shown to have a crucial role in the repression of mammalian target of rapamycin (mTOR). Nonetheless, PRAS40 appears to have an oncogenic function in cancer cells. Whether PRAS40 mediates signaling independent of mTOR inhibition in cancer cells remains elusive. Here PRAS40 overexpression in lung adenocarcinoma and cutaneous melanoma was significantly correlated to worse prognosis. And we identified an unexpected role for PRAS40 in the regulation of nuclear factor (NF)-κB signaling. P65, a subunit of the NF-κB transcription factor complex, was confirmed to associate with PRAS40 by glutathione S-transferase co-precipitation. Importantly, we found that PRAS40 can enhance NF-κB transcriptional activity in a manner dependent upon PRAS40-P65 association. Furthermore, we found that a small p65-derived peptide can disrupt the PRAS40-P65 association and significantly decrease NF-κB transcriptional activity. These findings may help elucidate the pleiotropic functions of PRAS40 in cells and suggest a novel therapeutic strategy in cancer patients with high expression of PRAS40 and NF-κB.

8.
Meat Sci ; 74(2): 296-302, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22062839

RESUMEN

A total of 115 pork liver pastes were randomly collected in local markets from different brands, countries and containers. The concentrations of nine heavy metals (Cu, Ni, Cd, Fe, Mn, Pb, Cr, Co and Zn), determined by atomic absorption spectrometry, and some qualitative variables described on the labelling constituted the data set. Chemometrics analysis was performed combining principal components analysis (PCA), factor analysis (FA) and typical classification techniques, such as linear discriminant analysis (LDA) and potential curves (PoCu) to classify pork liver pastes. Origin of the sample, manufacturer and effect of manufacturing process were taken into account to verify traceability, which is an important issue in food safety policies.

9.
Soud Lek ; 51(3): 42-6, 2006 Jul.
Artículo en Cs | MEDLINE | ID: mdl-16948447

RESUMEN

Scanning electron microscope improves the possibility of investigation of surroundings near of gunshot wounds in forensic medicine, it is the next subsequent method for differentiating of area of entrance and exit wound, supplemental method for determination of firing distance, permit of detection (GSR) on the hand of shooter and ensured describing of samples and their stored. Detection of GSR provides many information about composition of bullet and primer. Authors are demonstrating the possibility of detection of GSR on experimental shooting to the krupon (pigs' skin) in different situation (such as in a room and in outside area) and using of different weapon (hand gun CZ No.75 and machine gun No.58).


Asunto(s)
Traumatismos Craneocerebrales/patología , Balística Forense , Microscopía Electrónica de Rastreo , Heridas por Arma de Fuego/patología , Animales , Patologia Forense , Humanos , Fantasmas de Imagen , Porcinos
10.
Chemosphere ; 150: 659-666, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26879292

RESUMEN

Silver nanoparticles (AgNP) are emerging pollutants. The use of novel materials such as Cu-(benzene 1,3,5-tricarboxylate, BTC) Metal-Organic Framework (MOFs), for AgNP adsorption and their removal from aqueous solutions has been studied. The effect of different parameters was followed and isotherm model was suggested. MOFs adsorbed fast and efficiently AgNP in the range C0 < 10 mg L(-1), being Freundlich isotherm (R = 0.993) these data fitted to. Among studied parameters a remarkable effect of chloride on sorption was found, thus their possible interactions were considered. The high adsorption efficiency of AgNP was achieved and it was found to be very fast. The feasibility of adsorption on Cu-(BTC) was proved in spiked waters. The results showed the potential interest of new material as adsorbent for removing AgNP from environment.


Asunto(s)
Cobre/química , Nanopartículas del Metal/análisis , Compuestos Organometálicos/química , Plata/análisis , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Adsorción , Coloides , Estructuras Metalorgánicas
11.
J Chromatogr A ; 1084(1-2): 7-12, 2005 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-16114229

RESUMEN

Huperzine A, natural product from Huperzia serrata, is quite an important compound used to treat the Alzheimer's disease as a food supplement and also proposed as a prospective and prophylactic antidote against organophosphate poisoning. In this work, simple and fast capillary electrophoresis (CE) procedure with UV detection (at 230 nm) for determination of Huperzine A was developed and optimized. Capillary electrophoresis determination of Huperzine A was optimized using a combination of the experimental design (ED) and the artificial neural networks (ANN). In the first stage of optimization, the experiments were done according to the appropriate ED. Data evaluated by ANN allowed finding the optimal values of several analytical parameters (peak area, peak height, and analysis time). Optimal conditions found were 50 mM acetate buffer, pH 4.6, separation voltage 10 kV, hydrodynamic injection time 10 s and temperature 25 degrees C. The developed method shows good repeatability as relative standard division (R.S.D. = 0.9%) and it has been applied for determination of Huperzine A in various pharmaceutical products and in biological liquids. The limit of detection (LOD) in aqueous media was 0.226 ng/ml and 0.233 ng/ml for determination in the serum.


Asunto(s)
Electroforesis Capilar/métodos , Redes Neurales de la Computación , Sesquiterpenos/análisis , Alcaloides , Humanos , Reproducibilidad de los Resultados , Sesquiterpenos/sangre , Rayos Ultravioleta
12.
J Chromatogr A ; 1081(1): 48-54, 2005 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-16013597

RESUMEN

The polyphenols (some of them are also called phytoalexins, flavonols, flavanons, flavanonols, flavons, flavanols, and anthocyanines) are usually marked as potent antioxidants or radical scavengers which assist the body cells against oxidation. Polyphenols in wine are also considered to explain so called French paradox (long life aging and low number of coronary diseases despite of high alcohol and fat consumption). The total polyphenolic content (TPC) and total antioxidant potential (TAP) were determined by photometry and found strongly correlated. This finding suggests that the determination of TAP can be replaced by a more simple procedure of TPC determination. Capillary zone electrophoresis (CZE) with preconcentration by solid phase extraction (SPE) was applied for some polyphenols determination and for obtaining electropherograms of the SPE extracts (fingerprints). From mathematical evaluation of the fingerprints, prediction of cultivars and vintage using artificial neural networks (ANN) was done with more than 90% correct prediction. The study was performed on a set of 47 samples of young wines (vintage 1999-2002) from south Moravia (Czech Republic) and New South Wales (Australia).


Asunto(s)
Antioxidantes/análisis , Electroforesis Capilar/métodos , Flavonoides/análisis , Redes Neurales de la Computación , Fenoles/análisis , Vino/análisis , Vino/clasificación , Flavonoides/aislamiento & purificación , Fenoles/aislamiento & purificación , Fotometría/métodos , Polifenoles
13.
Oncogene ; 34(12): 1487-98, 2015 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-24704832

RESUMEN

The ribosomal protein (RP)-HDM2-p53 pathway has been shown to have key roles in oncogene-induced apoptosis and senescence, but the mechanism regulating this pathway remains elusive. The proline-rich Akt substrate of 40 kDa (PRAS40) has recently been identified as a binding partner and inhibitor of the mechanistic (formerly referred to as mammalian) target of rapamycin complex 1 (mTORC1). Although other inhibitors of mTORC1 are known tumor suppressors, PRAS40 promotes cell survival and tumorigenesis. Here we demonstrate that Akt- and mTORC1-mediated phosphorylation of PRAS40 at T246 and S221, respectively, promotes nuclear-specific association of PRAS40 with ribosomal protein L11 (RPL11). Importantly, silencing of PRAS40 induces upregulation of p53 in a manner dependent on RPL11. This effect is rescued by wild-type PRAS40, but not by the RPL11-binding-null PRAS40T246A mutant. We found that PRAS40 negatively regulates the RPL11-HDM2-p53 nucleolar stress response pathway and suppresses induction of p53-mediated cellular senescence. This work identifies nuclear PRAS40 as a dual-input signaling checkpoint that links cell growth and proliferation to inhibition of cellular senescence. These findings may help to explain the protumorigenic effect of PRAS40 and identify the PRAS40-RPL11 complex as a promising target for p53-restorative anticancer drug discovery.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Núcleo Celular/metabolismo , Complejos Multiproteicos/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Línea Celular Tumoral , Citoplasma/metabolismo , Células HeLa , Humanos , Diana Mecanicista del Complejo 1 de la Rapamicina , Mutación , Fosforilación , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteínas Ribosómicas/metabolismo , Transducción de Señal , Proteína p53 Supresora de Tumor/metabolismo
14.
FEMS Microbiol Lett ; 62(2-3): 163-9, 1991 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-2040426

RESUMEN

Cocultures consisting of strains converting chlorobiphenyls to the respective benzoates or catechols and of chlorobenzoate degraders were investigated for the mineralization of chlorobiphenyls. Stable mixed cultures were obtained with 4-chlorobiphenyl, while those with 2-chloro- or 3-chlorobiphenyl were found to be unstable and released only low yields of chloride. When both sets of enzyme sequences were combined in one organism, Pseudomonas cepacia strain JH230, by conjugative transfer of genes of the biphenyl degradation sequence, the total degradation of 2-chloro-, 3-chloro-, 4-chloro-, 2,4-dichloro-, and 3,5-dichlorobiphenyl was achieved.


Asunto(s)
Compuestos de Bifenilo/metabolismo , Pseudomonas/metabolismo , Arocloros/metabolismo , Benzoatos/metabolismo , Biodegradación Ambiental , Catecoles/metabolismo , Hibridación Genética , Cinética , Pseudomonas/aislamiento & purificación
15.
FEMS Microbiol Lett ; 108(2): 211-7, 1993 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-7683620

RESUMEN

The hybrid Pseudomonas cepacia strain JHR22 was tested for its ability to degrade Aroclor 1221 in soil. The influence of supplements--mineral salts and trace elements--on the degradation was investigated. Disappearance of Aroclor 1221 congeners, occurrence of metabolites, and release of chloride were measured under different conditions. After 45 days the hybrid organism, strain JHR22, was still present at high numbers in soil, independently of whether the soil had been sterilized prior to inoculation or not. There was only a minor difference in degradation efficiency between sterilized and untreated soil with about 70% release of chloride when 10(7) cells/g soil were inoculated. The whole hybrid pathway, originating from three different strains, was found to be stable under the conditions tested. Mineral salts did not significantly affect the degradation rate or survival of the hybrid strain.


Asunto(s)
Arocloros/metabolismo , Burkholderia cepacia/metabolismo , Microbiología del Suelo , Biodegradación Ambiental , Burkholderia cepacia/genética , Burkholderia cepacia/crecimiento & desarrollo , Quimera , Cloruros/metabolismo , Clorobenzoatos/metabolismo
16.
J Chromatogr A ; 834(1-2): 321-7, 1999 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-10189692

RESUMEN

The thiocyanate complexes of Pd(II), Pt(II) and Pt(IV) were studied by capillary zone electrophoresis. Pd(II) can be detected in the form of the thiocyanate complex at 305 nm with higher sensitivity than in the form of its chloro complex (absorption maximum 214 nm). A detection limit equal to 5 ppb for Pd has been finally achieved. The possibility of simultaneous determination of Pd(II) and Pt(IV) in the form of thiocyanate complexes has also been demonstrated. When the method optimized for the determination of Pt(II) was applied to the drugs Cykloplatin and Ribocarbo (containing carboplatin) and Platidiam (containing cisplatin), good agreement of the platinum content with the declared value was obtained. Samples of vehicle exhaust particulates (National Institute for Environmental Studies, Japan, No. 8 reference material) were also analyzed.


Asunto(s)
Antineoplásicos/análisis , Carboplatino/análisis , Electroforesis Capilar , Paladio/análisis , Platino (Metal)/análisis , Tiocianatos/análisis , Cisplatino/análisis , Espectrofotometría , Emisiones de Vehículos/análisis
17.
J Chromatogr A ; 772(1-2): 271-6, 1997 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-9226929

RESUMEN

In this work a new sensitive capillary zone electrophoresis method for the direct determination of procainamide (PA) and N-acetylprocainamide (NAPA) in pharmaceutical formulations and urine samples without any extraction and/or preconcentration steps has been developed. The determination was carried out in a fused-silica capillary of 43.5 cm (35.9 cm length to the detector) x 0.75 micron J.D. Phosphate 0.05 M buffer was used as the background electrolyte and 10 kV separation voltage was applied. The separation of PA and NAPA is possible in a wide range of pH from 1.7 to 9.7. However, in order to avoid the effect of the urine matrix, it is optimal to work at pH 7.7. The determination of PA and NAPA takes less than 5 min while high resolution is achieved. The detection limits obtained, 1.235 micrograms/ml and 0.359 microgram/ml for PA and NAPA respectively, are lower than those for GC method normally reported.


Asunto(s)
Acecainida/análisis , Electroforesis Capilar , Procainamida/análisis , Acecainida/orina , Animales , Antiarrítmicos/análisis , Antiarrítmicos/farmacología , Antiarrítmicos/orina , Cápsulas , Química Farmacéutica , Electroquímica , Concentración de Iones de Hidrógeno , Estructura Molecular , Procainamida/orina , Ratas , Espectrofotometría
18.
J Chromatogr A ; 895(1-2): 345-50, 2000 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-11105880

RESUMEN

Capillary zone electrophoresis has been used for the characterization and separation of humic acids. It was found that addition of saccharides like alpha-, beta-, gamma-cyclodextrins, maltose, hydroxyethylcellulose or dextran sulfate in the background electrolyte (50 mM Na2 B4 O7, pH 9.6) yields better separation patterns and highly reproducible electropherograms. Electropherograms with higher numbers of peaks and high reproducibility were obtained with alpha- and beta-cyclodextrins or with a mixture of alpha- + gamma-cyclodextrin-modified background electrolytes. Separation was carried out with the cathode at the detector end of the column. Adsorption of humic acids to the capillary wall was diminished using an epoxy-coated capillary tube.


Asunto(s)
Ciclodextrinas/química , Electrólitos/química , Electroforesis Capilar/métodos , Sustancias Húmicas/análisis , Oligosacáridos/química , Reproducibilidad de los Resultados
19.
J Chromatogr A ; 802(1): 121-8, 1998 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-9588015

RESUMEN

A new capillary zone electrophoresis (CZE) method for the determination of tacrine (THA), 7-methoxytacrine (7-MTHA) and their basic metabolites (THAm, 7-MTHAm) in pharmaceutical and biological samples (urine and serum) was developed. Separation of all compounds by CZE was carried out using a 46.6 cm untreated fused-silica capillary applying 20 kV separation voltage using 50 mM phosphate buffer of pH 2.8 for THA and THAm and of pH 7.8 for 7-MTHA and 7-MTHAm as background electrolyte (BGE). Detection was carried out at 240 nm (THA and THAm) and 248 nm (7-MTHA and 7-MTHAm). THA and THAm were separated in less than 4 min while 7-MTHA and 7-MTHAm were separated in less than 7 min. The detection limits (SIN = 3) obtained were 3 ppb for THA and 4 ppb for 7-MTHA in aqueous solutions; 50 ppb for THA and 47 ppb for 7-MTHA for the determination in urine (diluted 1:10); 52 ppb for THA and 56 ppb for 7-MTHA, in deproteinized serum samples. The methods are suitable for therapeutic drug monitoring of the drugs.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Inhibidores de la Colinesterasa/análisis , Electroforesis Capilar/métodos , Nootrópicos/análisis , Tacrina/análisis , Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/orina , Calibración , Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/metabolismo , Concentración de Iones de Hidrógeno , Nootrópicos/química , Nootrópicos/metabolismo , Sensibilidad y Especificidad , Tacrina/química , Tacrina/metabolismo
20.
J Chromatogr A ; 874(1): 111-9, 2000 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-10768505

RESUMEN

A method for separation and determination of polyphenols in wine by capillary zone electrophoresis (CZE) without any preconcentration step is described. The sensitivity and limits of detection for gentisic and p-coumaric acid are better than those previously published. The effect of a possible C18 solid-phase extraction prior to the CZE analysis was examined. The developed optimized method (without any extraction step) was applied to the analysis of wines from Tenerife, Canary Islands.


Asunto(s)
Electroforesis Capilar/métodos , Flavonoides , Fenoles/aislamiento & purificación , Polímeros/aislamiento & purificación , Vino/análisis , Polifenoles
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