Vol 74, No 2 (2019)

Study into the effect of vitamins A and E on total and differential leukocyte count, as well as morphometric parameters of lymphocytes in three carnivorous species—dark brown American mink (Neovison vison, Mustelidae), blue fox (Vulpes lagopus, Canidae), and silver fox (V. vulpes, Canidae)—was conducted. The highest white blood cells count (WBC count) and the largest surface area of lymphocytes and their nuclei in the peripheral blood were observed in mink, while the lowest indices were found in silver fox. Additional supplementation with vitamins A and E for 14 days had no effect on the WBC and differential leukocyte count, except for silver foxes receiving vitamin E, in which a decrease in relative eosinophils and monocytes content was observed. The action of vitamins was mainly manifested in changes in the lymphocytes’ morphometric parameters. The addition of vitamin A into the diet of mink and silver fox and vitamin E into only mink’s diet led to an increase in the surface area of lymphocytes and, in some cases, their nuclei, which was accompanied by a rise in the cytoplasm size in mink cells. In blue fox, on the contrary, both vitamins induced a decrease in the surface area of the lymphocytes and their nuclei. The observed changes may be associated with the immunomodulatory effects of vitamins A and E of the studied species of carnivorous mammals, while the found differences may be associated with features of the morphologic and functional organization of lymphocytes and the immune status.

Cultivation of diatom algae is associated with many problems, one of which concerns the contamination of cultures with various microorganisms. A representative of kinetoplastids, the free-living bacteriotroph Bodo saltans Ehrenberg, 1832, can often be found among contaminants. In the case when B. saltans reaches a high abundance, diatom cells cease to divide, some of them die, becoming a substrate for the development of bacteria, and then the substrate for the next trophic link: kinetoplastids. For the decontamination of diatom cultures, we used amphotericin B, a polyene macrocyclic antibiotic active against some protozoa and fungi. The effect of the drug on B. saltans in cultures of eight species of diatoms, including Ardissonea crystallina (C. Agardh) Grunow, Climaconeis scalaris (Brébisson) E.J. Cox, Entomoneis paludosa (W. Smith) Reimer, Haslea karadagensis Davidovich, Gastineau & Mouget, Pleurosigma aestuarii (Brébisson ex Kützing) W. Smith, Pleurosigma sp., Pseudo-nitzschia calliantha Lundholm, Moestrup & Hasle, and P. pungens (Grunow ex P.T. Cleve) Hasle, was investigated. The rate of division of diatom cells exposed to amphotericin B, depending on the dose and duration of exposure, was experimentally determined. Recommendations on the use of amphotericin B for the decontamination of diatom cultures from B. saltans are given.

Non-denaturing fluorescent in situ hybridization (ND FISH) is a convenient method of cytogenetic research. Compared to the standard method, ND FISH is fast and easy to perform and requires less time, reagents, and tools. Thus, it is gaining increasing popularity among different groups of scientists and is used to accomplish various scientific tasks. However, when using this method to visualize the chromosomes of wheat and its wild relatives, we faced some peculiarities of its application when oligonucleotide probes are used. In this paper, we compare the three following methods: two different versions of denaturating and non-denaturating FISH. In the standard procedure and its modifications, chromosomes are treated with formamide at high temperature that results in the denaturation of supercoiled DNA of plant chromosomes. In the non-denaturing FISH, this step is omitted, which makes it possible to keep the native chromosome structure and, thus, is more time and cost effective. In our work, all methods demonstrated their efficiency. Non-denaturing FISH is characterized by ease and convenience but less reproducibility in a series of experiments. The standard protocol and its modifications are most stable and reliable, but negatively affect chromosome morphology. In successive hybridizations on the same slide (sequential FISH), we recommend a combination of these methods, with primary testing using a standard protocol and subsequent hybridization using the ND-FISH method.

Male hybrid mice (F1 CBA × C57BL/6J) were kept for 1.5 h at 39.5°С. In cognitive tests (extrapolation and puzzle-box elementary logic task solution), mice of the experimental groups (after exposure to an elevated temperature) solved the tasks more quickly and more successfully, while their activity in the “small open field” (in which no stress-inducing stimuli were present) and in the Porsolt test (unescapable swimming) was higher than in control mice. In separate experiments, the temporary impairment in the adult neurogenesis (the decrease of new cell numbers detected immunо-histochemically by the marker Ki67) after elevated temperature exposure was demonstrated in both the subgranular area of dentate fascia and in the subventricular proliferative zone of the forebrain. The heating treatment was accompanied by the increase of HSP-70 expression at the time point 3 h after the treatment, while no differences from control were found after 24 h.

Coupling of EEG rhythms is an important indicator of the functional state of the human brain. There currently exist three theories explaining this coupling: (1) communication of neuronal populations, (2) neuronal coupling, and (3) coupling between generators of the frequencies being studied. It is known that the theta rhythm is associated with the functioning of cortico-hippocampal and alpha-rhythm-thalamo-cortical systems, and the beta rhythm can be included in the activity of both cortico-subcortical systems. The present work may clarify the features of the above-mentioned cortico-subcortical systems. There is a number of publications devoted to the study of EEG rhythm coupling in various types of psychical activity. At the same time, a concern for coupling of the rhythms at different sleep stages appeared in recent years. The task of our work included the study of coupling between theta, alpha, and beta EEG rhythms at the first stage of sleep. The study involved 22 subjects from 18 to 22 years old. Multichannel EEG was recorded during daytime sleep of the experiment participants. EEG segments with well-expressed theta rhythm were selected for the processing since it is “dominant” at the first stage of sleep. Bandpass filtering of the EEG signal was then performed. The following rhythms were discriminated: theta rhythm (4–7 Hz), alpha rhythm (8–13 Hz), beta-1 (14–19 Hz), and beta-2 (20–25 Hz) rhythms. Afterwards, for each range at each second, the average amplitude was calculated as the square root of the EEG signal dispersion. The Pearson correlation coefficient was used as a measure to evaluate coupling of EEG rhythms. As a result, it was established that the first stage of sleep is characterized by: (1) a lack of connections between the theta rhythm and other rhythms, (2) the presence of alpha–beta-1, alpha–beta-2, and beta-1–beta-2 links, (3) the increase in theta amplitude, and (4) the decrease in the amplitudes of alpha and beta rhythms. As was noted above, the theta rhythm is associated with functioning of the cortico-hippocampal system, and the alpha rhythm is associated with the thalamo-cortical system. In our work, two coexisting types of functioning of these systems are shown: (1) the “independent” one of the cortico-hippocampal circuit and (2) the thalamo-cortical one, connected with other rhythms, particularly with the beta rhythm. This heterogeneity is probably a condition for the first stage of sleep to be potentially unstable. An increase in theta rhythm amplitude at the first stage of sleep against the state of quiet wakefulness is shown. This is traditionally associated with the increase in ascending effects of limbic structures of the brain. Amplitudes of alpha and beta rhythms at the first stage of sleep significantly decreased, which indicates an attenuation of the influence of prefrontal cortical regions on posterior hypothalamus centers. Hence, it can be assumed that the onset of the first stage of sleep can be provided by the heterogenous character of rhythm coupling, and, correspondingly, different functioning of cortico-hippocampal and thalamo-cortical systems.

The paper is a systematic review of using the pharmaceutical substance, Carnoy’s solution, to reduce the number of recurrences of such tumors as keratocystic odontogenic tumor and ameloblastoma. These are benign yet aggressive jaw tumors with a high percentage of recurrences (up to 60–80%). Surgical treatment of the above-described lesions can be performed using: (1) marsupialization (recurrence rate up to 24.8%); (2) enucleation with or without adjunct therapy; therapy may include cryotherapy with liquid nitrogen (recurrence rate up to 23.1%), peripheral ostectomy (recurrence rate up to 20%), and bone cavity treatment with Carnoy’s solution (recurrence rate up to 6.6%); (3) marginal/segmental resection of the jaw (recurrence rate up to 2.5%). Despite the low percentage of recurrences when using marginal/segmental resection, this method requires a longer and more expensive anesthetic and surgical intervention as well as longer postoperative and rehabilitation periods. With the use of Carnoy’s solution, it became possible to reduce the risks of recurrence of keratocystic odontogenic tumors and ameloblastomas from 60–80 to 6.6‒11.5%. Worldwide today, not only Carnoy’s solution recommended by Cutler and Zollinger in 1933 is applied but also its modifications that are not inferior to the original substance in terms of removal efficiency of the remaining cystic cells. The safety of the use of the solution near the vessels and nerves is confirmed by works of a number of authors. It is concluded that, despite the large number of surgical treatments of both keratocystic odontogenic tumors and ameloblastomas, enucleation with the use of Carnoy’s solution is the optimal method of choice for these diseases.

It has been shown that factor X activity determined in normal plasma using Aspergillus ochraceus protease is comparable with the activity determined with a commercial analogue, a protease from Russell’s viper venom (RVV-X^®). It was revealed that the protease of A. ochraceus, along with the RVV-X^® preparation, can be used to determine the content of factor X in the plasma with its reduced content. A study of the protease activity of A. ochraceus as an activator to factor X showed that it is slightly higher compared to the snake venom preparation, which can make A. ochraceus protease a promising substitute for the snake activator in diagnostics for determining the content of factor X.