Репозиторий Университета

© 2019 Elsevier B.V. A validated approach to determine various methionine cycle metabolites (S-adenosylmethionine, S-adenosylhomocysteine, and methylthioadenosine) in human blood plasma is offered. The approach is based on solid-phase extraction (with grafted phenylboronic acid) and derivatization with chloroacetaldehyde followed by ultra-performance liquid chromatography with fluorescence detection. We used a 100 × 2.1 mm × 1.8 μm C18 column for the selective separation of analytes. Chromatographic separation was achieved with gradient elution of acetonitrile (flow rate 0.2 mL/min) from 2 to 20%. The eluent was initially composed of 10 mM KH2PO4 with 10 mM acetic acid and 25 μM heptafluorobutyric acid. The total analysis time was 11 min. Validation of the method included detection of the limit of detection (2 nM), limit of quantification (5 nM), accuracy (97.2–101%), and intra- and interday precision (2.2–9.0%). Analysis of plasma samples from healthy volunteers revealed that the average levels of S-adenosylmethionine, S-adenosylhomocysteine, and methylthioadenosine were 93.6, 20.9 and 14.8 nM, respectively.

© 2019, Springer Science+Business Media, LLC, part of Springer Nature. The effects of inhalation exposure to a mixture containing acetone, acetaldehyde, and ethanol in concentrations typical of closed environment in space vehicles on the structure of mesenteric lymph nodes in F1 male mice were studied by histological technique. The long-term exposure to modeled atmosphere led to pronounced structural changes in these nodes that were clearly seen on day 22 and increased by day 36 of the experiment. The thickness of the capsule and trabeculae of mesenteric lymph nodes as well as diameter of lymphatic sinuses did not differ from the control values up to day 8, but then increased on days 22-70. Starting from day 22, the thickness of the medullary cords decreased and attained the minimum to the end of the experiments, which can indicate depletion of immunocytopoiesis and inhibition of humoral immunity. The present data are important for the space medicine, because they indicate structural changes in the peripheral lymphoid organs, the key elements of immune system.