Coulometric determination of NAD+ and NADH in normal and cancer cells using LDH, RVC and a polymer mediator

An electrochemical method for the measurement of NAD(+) and NADH in normal and cancer tissues using flow injection analysis (FIA) is reported. Reticulated vitreous carbon (RVC) electrodes with entrapped l-lactate dehydrogenase (LDH) and a new redox polymer containing covalently bound toluidine blue O (TBO) were employed for this purpose. Both NAD(+) and NADH were estimated coulometrically based on their reaction with LDH. The latter was immobilized on controlled pore glass (CPG) by cross-linking with glutaraldehyde and packed within the RVC. The concentrations of NAD(+) and NADH in the tissues, estimated using different electron mediators such as ferricyanide (FCN), meldola blue (MB) and TBO have also been compared. The effects of flow rate, pH, applied potential (versus Ag/AgCl reference) and adsorption of the mediators have also been investigated. Based on the measurements of NAD(+) and NADH in normal and cancer tissues it has been concluded that the NADH concentration is lower, while the NAD(+) concentration is higher in cancer tissues. Amongst the electron mediators TBO was found to be a more stable mediator for such measurements.     

Synthesen in der Naphthalinreihe: Methoxylierte Tetralone und Naphthole

Ohne ZusammenfassungHerrn Prof. Dr.A. Franke in aufrichtiger Verehrung zum 80. Geburtstag gewidmet.     

Thermal transformations of oligoarylenes

Journal of Thermal Analysis and Calorimetry - Thermal transformations of oligoarylenes, relating to polymers with conjugate systems, have been investigated in air and in vacuo, depending on the...     

Zu den Spektren aromatischer Azine. I Berechnung der Energieterme des Benzalazins mit Hilfe der LCAO-MO-Methode

Zusammenfassung Mit Hilfe der einfachen LCAO-MO-Methode werden die Energieterme der -Elektronen des Benzalazins, seiner Ammoniumionen und die von 12 weiteren Strukturen, die durch Verdrehung bestimmter Teile des Moleküls als isolierte Systeme auftreten können, berechnet. Die Diskussion der Lage der Energieterme im Termschema des Benzalazins und seiner Ionen an Hand der Säkulardeterminanten und der aus ihnen abgeleiteten Größen führt zu einer Eingrenzung der einzelnen Energieterme und der Anregungsenergien.Mit 4 AbbildungenMeinem verehrten Lehrer, Herrn, Prof. Dr.F. Wessely, zum 60. Geburtstag in Dankbarkeit gewidmet.     

Bifunctional monodisperse microspheres of copolymers of methyl methacrylate and N-vinylformamide

Emulsion copolymerization of methyl methacrylate and N-vinylformamide in the presence of azo initiators and dextran as a polymeric stabilizer was analyzed with the aim to prepare monodisperse polymer microspheres with a polyfunctional surface. Hydrolysis of comonomer units and cationic groups of the initiator residues in the surface layer of the particles to give amphoteric surfaces containing carboxy and amino groups was studied. The optimal conditions of formation of monodisperse microspheres with diameter varied in the 340–660 nm range and the conditions of their hydrolysis, which allow direct control of the amount and nature of functional groups on their surface, were found.     

Synthesis of Esters of Dioxane Alcohols and Their Performance as Plasticizers for Polyvinyl Chloride Compounds

A procedure was developed for preparing a plasticizer for polyvinyl chloride compounds from the fraction of dioxane alcohols. The main physicochemical properties of the new plasticizer were determined. Items prepared from formulations containing the new plasticizer were fabricated and tested in laboratory.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 6, 2005, pp. 972–976.Original Russian Text Copyright © 2005 by Glazko, Gur’yanova, Levanova, Kozlova, Neiman.     

Hetrocyclic Thiones and Their Analogs in Reactions of 1,3-Dipolar Addition: VI. Reactions of Thiazoline-2-thione with Nitrile Imines

Reactions of thiazoline-2-thione with C,N-disubstituted nitrile imines were investigated. The reaction products are substituted 2-(1,3,4-thiadiazol-2-ylideneamino)ethanethiols and bis[2-(1,3,4-thiadiazol-2-ylideneamino)ethyl] disulfides. The reaction of thiazoline-2-thione with a double excess of nitrile imine did not considerably change the process route. The structure of compounds obtained was proved by X-ray diffraction analysis. A presumable scheme is given describing the formation of compounds obtained.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 5, 2005, pp. 776–782.Original Russian Text Copyright © 2005 by Firsova, Dolgushina, Polukeev, Ioannisyan, Zavodnik, Stash, Bel’skii, Galishev.