Biomedical subjects

Sergey Zaitsev

Publications and source records attributed to Sergey Zaitsev.

4 recordsLinked to original sources

PubMed2006

P-glycoprotein effect on the properties of its natural lipid environment probed by Raman spectroscopy and Langmuir-Blodgett technique.

Behavior of P-glycoprotein (Pgp) natural lipid environment within the membrane of CEM cells expressing Pgp in the quantities varying from 0% to 32% of the total amount of all membrane proteins is described for the first time. Observed cooperative effect of Pgp-induced increase of membrane stability, decrease of the temperature of gel-to-crystal lipids transition and predominance of the lipid liquid crystalline phase at physiological temperatures should have an impact in development of multidrug resistance phenotype of tumor cells by favoring the Pgp intercellular transfer and Pgp ATPase activity.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2004

Polyelectrolyte nanoparticles mediate vascular gene delivery.

PURPOSE: The purpose is to develop a non-viral gene delivery system that meets the requirements of colloidal stability of DNA complexes expressed in terms of no particle aggregation under physiologic conditions. The system should be used to transfect cardiovascular tissues. METHODS: We used a strategy based on the formation of polyelectrolyte nanoparticles by deposition of alternatively charged polyelectrolytes onto a DNA core. Polyelectrolytes were transfer RNA as well as the synthetic polyanion, polyvinyl sulfate (PVS), and the polycation polyethylenimine (PEI). The PEI/DNA complex formed the DNA core. RESULTS: We observed that the DNA is condensed by polycations and further packaged by association with a polyanion. These nanoparticles exhibited negative surface charge and low aggregation tendency. In vivo rat carotid artery experiments revealed high transfection efficiency, not only with the reporter gene but also with the gene encoding human urokinase plasminogen activator (Hu-uPA). Hu-uPA is one of the proteins involved in the recovery of the blood vessels after balloon catheter injury and therefore clinically relevant. CONCLUSIONS: A strategy for in vivo gene transfer is proposed that uses the incorporation of polyanions as RNA or PVS into PEI/DNA complexes in order to overcome colloidal instability and to generate a negative surface charge. The particles proved to be transfectionally active in vascular gene transfer.

Animals↗

PubMed2002

Myopathy-dependent changes in activity of ATPase, SDH and GPDH and NOS expression in the different fibre types of hamster muscles.

Proximal (vastus lateralis) and distal (gastrocnemius) muscles of 100-day-old normal and myopathic BIO TO-2 hamsters were analysed to study the effects of myopathy on the different muscle fibre types: SO (slow oxidative), FOG (fast oxidative glycolytic) and FG (fast glycolytic). Cytophotometric measurements of enzyme activities (myofibrillic adenosine triphosphatase, succinate dehydrogenase and glycerol-3-phosphate dehydrogenase), Western blot analysis of nitric oxide synthase (NOS) I, II, III isoforms and NOS II immunohistochemistry were performed. The following alterations were found in myopathic muscle fibres: all fibre types of both proximal and distal myopathic muscles showed decreased myofibrillic adenosine triphosphatase activity indicating depressed contractility. This was associated with depressed oxidative activity of the muscle fibres. A shift to more glycolytic metabolism was observed, mainly in FG fibres of proximal muscle. We found an increased NOS II expression in both myopathic muscle types investigated. It means that increased NO production inhibits force generation in myopathic muscle. NOS II immunoreactivity was found mainly in the cytoplasm of FG fibres. NOS I and NOS III expression was not significantly effected by this form of myopathy. Our findings demonstrate that muscle fibres of proximal and distal skeletal muscles of 100-day-old cardiomyopathic BIO TO-2 hamsters are altered with respect to contractility, metabolism and NOS II expression. FG fibres of the proximal muscle were effected most strongly.

Adenosine Triphosphatases↗

PubMed2002

Cytophotometrical and immunohistochemical analysis of soft palate muscles of children with isolated cleft palate and combined cleft lip and palate.

Palatal muscle biopsies from the cleft margin of children were subjected to cytophotometrical and immunohistochemical analysis. Muscle fiber types were classified according to the enzyme activity of myofibrillic adenosine triphosphatase, glycerol-3-phosphate-dehydrogenase and succinate dehydrogenase assessed cytophotometrically. Fiber type-related immunoreactivity of nitric oxide synthase (NOS) isoforms I, II, III, as a physiological modulator of skeletal muscle function, was related to the oxidative and glycolytic activity of the muscle fibers. Fast oxidative glycolytic fibers with high oxidative activity showed strong NOS I immunoreactivity, whereas fast glycolytic fibers with high glycolytic activity were stronger immunolabelled for NOS III. NOS II expression was similar in all fiber types. No differences in NOS immunoreactivity were found between the two investigated forms of deformity. Additionally to the usual skeletal muscle fiber types, a slow tonic fiber type was for the first time identified in cleft palate muscles. Comparison of two forms of cleft palate, isolated cleft palate and combined cleft lip and palate has shown decreased enzyme activities in muscle fibers of palatal muscles from combined cleft lip and palate. Fast oxidative glycolytic fibers were mainly effected. Cytophotometrical and immunohistochemical analysis indicated a depressed performance of the cleft palatal muscles from combined cleft lip and palate as a stronger deformity compared with isolated cleft palate.

Adenosine Triphosphatases↗