Alexander A. Sergievich

Influence of multi-walled carbon nanotubes on the cognitive abilities of Wistar rats

Studies of the neurobehavioral effects of carbon nanomaterials, particularly those of multi-walled carbon nanotubes (MWCNTs), have concentrated on cognitive effects, but data are scarce. The aim of this study was to assess the influence of MWCNTs on a number of higher nervous system functions of Wistar rats. For a period of 10 days, two experimental groups were fed with MWCNTs of different diameters (MWCNT-1 group, 8–10 nm; MWCNT-2 group, 18–20 nm) once a day at a dosage of 500 mg/kg. In the open-field test, reductions of integral indications of researching activity were observed for the two MWCNT-treated groups, with a parallel significant (P<0.01) increase in stress levels for these groups compared with the untreated control group. In the elevated plus-maze test, integral indices of researching activity in the MWCNT-1 and MWCNT-2 groups reduced by day 10 by 51 and 62%, respectively, while rat stress levels remained relatively unchanged. In the universal problem solving box test, reductions in motivation and energy indices of researching activity were observed in the two experimental groups. Searching activity in the MWCNT-1 group by day 3 was reduced by 50% (P<0.01) and in the MWCNT-2 group the relevant reduction reached 11.2%. By day 10, the reduction compared with controls, was 64% (P<0.01) and 58% (P<0.01) for the MWCNT-1 and MWCNT-2 groups, respectively. In conclusion, a series of specific tests demonstrated that MWCNT-treated rats experienced a significant reduction of some of their cognitive abilities, a disturbing and worrying finding, taking into consideration the continuing and accelerating use of carbon nanotubes in medicine and science.

A guide to acquired vitamin K coagulophathy diagnosis and treatment: the Russian perspective

Physicians often come across with cases of vitamin K antagonists–dependent coagulopathy for reasons such as accidental use of the vitamin K antagonists (VKA), excessive administration of prescribed anticoagulants of indirect action or not reported administration of vitamin K antagonists due to memory impairment and/or other mental disorders, even deliberate use thereof (attempt to murder or suicide). Rodenticide-poisoning (coumarins, warfarins) via food or occupational accidents are difficult to diagnose. This article discusses different types of acquired vitamin K-dependent coagulopathy. Differential diagnosis is primarily based on patient statements before additional causes of vitamin K deficiency are explored. Even when pathological vitamin K deficiency is not determined, appropriate and urgent medical treatment is necessary: administration of fresh frozen plasma or concentrated factors of the prothrombin complex, administration of vitamin K remedies along with symptomatic therapy. With early diagnosis and prescription of appropriate therapy, prognosis is favorable.Graphical abstractReasons for vitamin K antagonists–dependent coagulopathy cases

Oral application of carbon nanofibers in rats increases blood concentration of IL6 and IL10 and decreases locomotor activity

Carbon nanofibers (CNF) are versatile nanomaterials that are widely used in various fields of science and technology. As a consequence, animals as well as humans may be exposed to such compounds via different routes. We hypothesized that oral intake of CNF will lead to an inflammatory reaction and consequently induce behavioral impairments. To address this issue, rats were fed with 500mg/kgCNF for 14days and their locomotor activity, emotional status and cognition were quantified by testing the animals in an open field set-up, elevated plus maze and in the universal problem solving box which provides information about motivation and cognition. The behavioral tests were performed 3 times within 10days. At the end of the experiment, blood samples were collected and the plasma concentrations of IL-6, IL-8, IL-1β, IL-10 and IL-18 were measured. Our results demonstrated an inflammatory reaction determined by a significantly elevated IL-6 concentration. This, however, was counteracted by an even more pronounced increase in IL-10. The behavioral effects were restricted mainly to a decrease in locomotor activity which was significant in the open field test, as well as the elevated plus maze. Other parameters indicative of cognitive performance were not influenced and also the emotional status was largely unaffected. In conclusion, our results revealed that oral intake of 500mg/kgCNF induced some adverse effects, which, however, can be still partially compensated by the organism.

Results of geological and geochemical investigations of Kaplanov kudurs in Sikhote-Alin, Russian Far East

A series of studies was carried out at the Kaplanov kudurs in the upper reaches of the Kolumbe river (the territory of Sikhote-Alin biosphere reserve, Russia) in order to confirm the “rare earth” hypothesis as one of the possible causes of geophagy and consumption of mineralized spring water on kudurs. The mineral and chemical content of spring water and mineral soils of lithogenic substances, consumed by animals at the Kaplanov kudurs in the upper reaches of the Kolumbe river (the territory of Sikhote-Alin biosphere reserve, Russia). Previously unknown data on microelement composition of the minerals consumed by animals was received. It was found that the composition of water of various kudurs differs immensely and forms mainly in restored gley environments (sometimes in restored environments with high concentrations of sulfates). It was also found out that the microelement composition in spring waters can significantly vary over time. When this happens, the most variable are Al, Fe, Co, Ni, Cu, Zn, Ba, Sr, and some rare metals from the rare earth elements (REE) group and lanthanides. It was confirmed that one of the elements which attracts the animals in spring water and in “edible” subsoils is Na. However, Na is not the only element, which is searched by the animals at the kudurs, as consumed water and soil on some kudur contain an insignificant amount of it with simultaneously increased concentrations of a number of trace elements, including from the group REE.

Results of mineralogical–geochemical researches of two high-mountain kudurs within territory of Caucasus

The article focuses on the development of the reasons of the consumption by the wild herbivorous animals of the subsurface rocks in the apical part of Alous and Atamagu mountains, situated on the territory of the Caucasian State Biosphere Reserve. It was investigated the mineralogical and geochemical peculiarities of the eaten and not eaten rocks, the chemical composition of their water extracts and also the chemical composition of vegetation. It was determined that the consumed rocks mainly consist of the clay mineral illite, crystalline silica, hydrous micas and chlorites and are the derivatives of eolation of the Paleozoic granitoids in one case, and argillite–aleurolites of the Jurassic age in the second case. The chemical composition of the aqueous extracts demonstrated the relatively low contents of natrium and other macrocomponents in comparison with the non-consumed rocks, and also the increased content of lanthanides. The elicited facts are not compatible with the hypothesis that the pursuance for geophagia in animals at Caucasus can be connected with the peculiarities of elements change from lanthanide group in the organism.