Репозиторий Университета

© 2019, © 2019 Informa UK Limited, trading as Taylor  &  Francis Group. Human polymorphonuclear leukocytes (PMNLs, neutrophils) play a major role in the immune response to bacterial and fungal infections and eliminate pathogens through phagocytosis. During phagocytosis of microorganisms, the 5-lipoxygenase (5-LOX) pathway is activated resulting in generation of leukotrienes, which mediate host defense. In this study, a library of oligodeoxyribonucleotides (ODNs) with varying numbers of human telomeric repeats (d(TTAGGG)n) and their analogues with phosphorothioate internucleotide linkages and single-nucleotide substitutions was designed. These ODNs with the potential to fold into G-quadruplex structures were studied from structural and functional perspectives. We showed that exogenous G-quadruplex-forming ODNs significantly enhanced 5-LOX metabolite formation in human neutrophils exposed to Salmonella Typhimurium bacteria. However, the activation of leukotriene synthesis was completely lost when G-quadruplex formation was prevented by substitution of guanosine with 7-deazaguanosine or adenosine residues at several positions. To our knowledge, this study is the first to demonstrate that G-quadruplex structures are potent regulators of 5-LOX product synthesis in human neutrophils in the presence of targets of phagocytosis. Communicated by Ramaswamy H. Sarma.

© 2018 Vladimir A. Chistyakov, Alexander V. Usatov, Aleksander I. Klimenko, Maria A. Kolosova, Eugenia V. The abundance of potential genotoxins makes it necessary to improve microbial test systems that allow to identify these substances quickly. At the same time, the methodology of metabolic activation of promutagens in vitro is very important. Microsomal preparations of rodents, which are generally used for that, have significant disadvantages associated with the potential health risks of the inducers of the metabolism of microsomal cytochromes. For the metabolic activation of promutagens, we have developed a protocol of microsomal homogenate fraction (S-9) preparation. We propose to complement the set of methods for quality control of feeds for valuable and rare chicken breeds with the Ames test (Salmonella/microsome) using the activated chicken hepatic S-9 homogenate fraction.

© 2018 Media Sphera Publishing Group.All Rights Reserved. The article describes the clinical observation with an unfavorable outcome of the generalized form of salmonella infection caused by Salmonella typhimurium group B in a woman of 60 years without immunodeficiency, complicated by the development of multiple abscesses of the lower parts of abdominal cavity, probably of appendicular origin. In a short literary review, the pathogenetic mechanisms that contribute to the formation of generalized and extraintestinal forms of salmonella infection are discussed.