Biomedical subjects

Anna Kisiel

Publications and source records attributed to Anna Kisiel.

4 recordsLinked to original sources

PubMed2006

Plastic reference electrodes and plastic potentiometric cells with dispersion cast poly(3,4-ethylenedioxythiophene) and poly(vinyl chloride) based membranes.

A simple procedure of preparing low cost, planar and disposable reference electrodes for potentiometric applications is presented. This method is essentially the same as used for obtaining all-plastic ion-selective electrodes and thus promising for simple fabrication of complete cells. Commercially available aqueous dispersion of poly(3,4-ethylenedioxythiophene) doped by poly(4-styrenesulfonate) ions (PEDOT-PSS, Baytron P) is simply cast on a non-conducting plastic support (transparent foil for laser printers). This layer is covered by a non-selective poly(vinyl chloride) based membrane containing solid AgCl and KCl, added to obtain a stable potential. The conducting polymer layer plays a double role, of electrical contact and ion-to-electron transducer, enhancing the potential stability. The reference electrodes obtained exhibit independence of the kind and concentration of electrolyte applied as well as very low sensitivity to interferences: redox reactants and H+ ions; they are also characterized by both potential stability and low polarisability, sufficient for potentiometric applications. Cells of plastic electrodes (indicator and reference ones) are tested using an arrangement with Pb2+ or Ca2+ selective sensors. Potentiometric characteristic of such cells is satisfactory, well comparable with that using a classical electrode arrangement.

Biosensing Techniques↗

PubMed2005

All-solid-state reference electrodes based on conducting polymers.

A novel construction of solution free (pseudo)reference electrodes, compatible with all-solid-state potentiometric indicator electrodes, has been proposed. These electrodes use conducting polymers (CP): polypyrrole (PPy) or poly(3,4-ethylenedioxythiophene) (PEDOT). Two different arrangements have been tested: solely based on CP and those where the CP phase is covered with a poly(vinyl chloride) based outer membrane of tailored composition. The former arrangement was designed to suppress or compensate cation- and anion-exchange, using mobile perchlorate ions and poly(4-styrenesulfonate) or dodecylbenzenesulfonate anions as immobilized dopants. The following systems were used: (i) polypyrrole layers doped simultaneously by two kinds of anions, both mobile and immobilized in the polymer layer; (ii) bilayers of polypyrrole with anion exchanging inner layer and cation-exchanging outer layer; (iii) polypyrrole doped by surfactant dodecylbenzenesulfonate ions, which inhibit ion exchange on the polymer/solution interface. For the above systems, recorded potentials have been found to be practically independent of electrolyte concentration. The best results, profound stability of potentials, have been obtained for poly(3,4-ethylenedioxythiophene) or polypyrrole doped by poly(4-styrenesulfonate) anions covered by a poly(vinyl chloride) based membrane, containing both anion- and cation-exchangers as well as solid potassium chloride and silver chloride with metallic silver. Differently to the cases (i)-(iii) these electrodes are much less sensitive to the influence of redox and pH interferences. This arrangement has been also characterized using electrochemical impedance spectroscopy and chronopotentiometry.

Chromatography, Ion Exchange↗

PubMed2004

[Neutrophils and selected cytokines in ulcerative colitis pathomechanism].

The aim of the study was to assess receptor CD11b and CD62L expression on neutrophils and IL-1beta, IL-6 and IL-8 level in children with ulcerative colitis. Thirty children aged 8-17 years were included in the study. The investigations were performed in the acute phase, prior to the treatment and during remission, 2 months after clinical improvement was obtained. The control group consisted of 12 children with chronic obstipation. IL-1beta, IL-6 and IL-8 serum level and receptor CD11b expression, especially on resting neutrophils, in children with severe and moderate course of the disease were statistically significantly higher; whereas CD62L expression was significantly lower in comparison with the controls and got back to normal during remission. Increased IL-1beta level was observed only in children with severe disease course. In children with mild process the results of the investigations were similar to the control group. In children with severe disease activity the proinflammatory cytokines levels in serum were elevated. The neutrophils in children with severe course of the disease manifested priming in peripheral blood before leaving the circulation.

Adolescent↗

PubMed2004

[Mucus physicochemical properties in children with ulcerative colitis].

The aim of the study was to estimate colonic mucus physicochemical state in children with ulcerative colitis. Investigations were performed in 36 children, aged 10-17 years, allotted into three groups dependently on the severity of the disease. The severity of the disease was estimated basing on Truelove-Witts criteria. Mucus analysis was performed with polyacrylamide gel electrophoresis (SDS-PAGE), electron paramagnetic resonance (EPR) and spectrophotometric method. Mucus fraction dissolved in normal saline was subject of investigations. Protein content was determined in this fraction with Lowry's method. The obtained results demonstrated different mucus solubility dependent on the severity of the disease. Mucus protein concentration increased whereas mucus viscosity decreased with the severity of the disease. Colonic mucus physicochemical properties change dependently on the disease severity. Determination of soluble protein fraction in mucus may be a useful marker in the estimation of the disease severity.

Adolescent↗