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In July 2023, the deaths of northern fur seals (Callorhinus ursinus) and Steller sea lions (Eumetopias jubatus) were noted in the Far East region of the Russian Federation on Tyuleniy [...]

Objective: to compare the objective results of ultrasound imaging of neck main arteries with echocardiography data, to assess the correlation patterns between the morphological characteristics of the structures.Material and methods. A total of 244 volunteers (who had no signs of significant hemodynamic disorders, surgical interventions on the heart and studied vessels) were examined, who underwent ultrasound imaging of the carotid arteries and echocardiography. All studies were performed using a single technique with an assessment of the diameters of common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA), vertebral arteries (VA), as well as intima-media complex (IMC). The echographic characteristics of the aortic wall, aortic and mitral valves were considered. The data obtained were grouped and subjected to statistical analysis.Results. Based on the diagnostic data obtained by echocardiography, eight groups were formed: (1) with signs of changes in the aorta; (2) with changes at the level of the aorta and aortic valve; (3) with changes in the aorta and mitral valve; (4) with changes in the aortic and mitral valves; (5) without signs of changes in the aorta, aortic and mitral valves; (6) with changes only in the aortic valve; (7) with changes only in the mitral valve; (8) with changes only at the level of the aortic and mitral valves. When assessing the differences between pairs of groups in cases of diagnosis of structural changes in the aortic walls and valvular heart apparatus, the indicators differed slightly, more often for IMC value. There were differences for ICA diameter when comparing Groups 1 and 4. Morphometric parameters of VA in cases of diagnosed changes did not reflect significant differences. The largest CCA diameter (5.8±0.7 mm) was noted in combination with changes in the aortic wall and heart valves. The smallest CCA diameter (5.0± 0.3) mm was in Group 6. The largest ICA (4.6±0.4 mm) and ECA (3.6±0.4) diameters were with changes in the mitral valve. The smallest ICA diameter (4.1±0.4 mm) was observed with changes only in the aortic walls. The smallest values for ECA and VA diameters were 2.8 mm, combined with changes in the aortic valve only. The most pronounced differences were obtained when comparing data in the absence of significant changes in the aortic walls and heart valves for CCA, VA, and ECA IMC.Conclusion. The presented results expand our understanding of the individual features of neck main arteries, accompanying changes in the aortic walls and valvular apparatus of the heart.

Relevance. Influenza A virus is characterized by a segmented single-stranded RNA genome. Such organization of the virus genome determines the possibility of reassortment, which can lead to the emergence of new virus variants. The main natural reservoir of most influenza A virus subtypes are wild waterfowl. Seasonal migrations gather waterfowl from all major migration routes to nesting areas near the northern and southern polar circles. This makes intercontinental spread of influenza A viruses possible. Objective ‒ to conduct molecular genetic monitoring and study the phylogenetic relationships of influenza A virus variants circulating in Antarctica in 2023. Materials and methods. We studied 84 samples of biological material obtained from birds and marine mammals in April‒May 2023 in coastal areas of Antarctica. For 3 samples, sequencing was performed on the Miseq, Illumina platform and phylogenetic analysis of the obtained nucleotide sequences of the influenza A virus genomes was performed. Results. The circulation of avian influenza virus in the Antarctic region was confirmed. Heterogeneity of the pool of circulating variants of the influenza A virus (H3N8, H1N1) was revealed. Full-length genomes of the avian influenza virus were sequenced and posted in the GISAID database (EPI_ISL_19032103, 19174530, 19174467). Conclusion. The study of the genetic diversity of influenza A viruses circulating in the polar regions of the Earth and the identification of the conditions for the emergence of new genetic variants is a relevant task for the development of measures to prevent biological threats.

BACKGROUND: Ovarian reserve reflects a woman's ability to successfully realize reproductive function. The assessment of ovarian reserve is an urgent task for clinical practice [1] and is important in scientific research. The use of computerized diagnostic image processing methods can accelerate and facilitate the performance of routine tasks in clinical practice. Their use in retrospective data analysis for scientific purposes allows to increase the objectivity of the study and supplement it with auxiliary information [2]. The issue of ovarian localization and follicle segmentation on ultrasound images has been previously investigated in other works. For instance, Z. Chen et al. [3] employed the U-net model to identify follicles on ultrasound images. Similarly, V.K. Singh et al. [4] addressed a related problem using a variant of U-net, namely UNet++ [5], which has gained considerable traction in the field of medical image analysis [6]. AIM: The study aimed to develop machine learning models for analyzing ovarian images obtained from an ultrasound machine. MATERIALS AND METHODS: An open dataset with a labeled ovary region was used for pre-training ovarian segmentation and follicle detection models. Subsequently, the dataset, which contains marked-up ovarian and follicle regions, was employed for training and testing. It encompasses a total of approximately 800 examples from 50 unique patients. The localization of follicles in an ultrasound image is a challenging task. To address this, the designed detector system was divided into two parts: ovary segmentation and follicle detection within the selected region. This approach allows the model to focus on a region where there are no other organs and various ultrasound artifacts that can be falsely perceived as the object under investigation. For the purpose of ovarian segmentation, the UNet++ architecture [5] was employed in conjunction with the ResNeSt encoder [8], which incorporates the SE-Net [9] and SK-Net [10] attention mechanisms. The object detection model is employed to identify the location of follicles within the ovary, as it enables precise enumeration of the number of follicles, even in the presence of overlapping structures, a capability that the segmentation model lacks. In our study, we used the YOLOv8 model [11]. Furthermore, data preprocessing has been employed to enhance the quality of model predictions. This has involved the identification and removal of regions with auxiliary information, the reduction of noise, and the augmentation of data. RESULTS: Two ovarian localization models are presented based on the results of this study. The first model is a segmentation model with an IoU quality of at least 50%. The second model is a detection model with a mAP quality of at least 65%. A third model is a model for follicle detection with subsequent follicle counting. This model has an MAPE error not exceeding 35%. CONCLUSIONS: The study resulted in the proposal of a method for applying machine learning techniques to the task of analyzing ultrasound images. The developed segmentation and detection models reduce the time and errors in analyzing ovaries and follicles in the images. The use of an attention mechanism and data preprocessing improves the quality of the models. The neural network for follicle detection provides follicle counting, even when follicles overlap.

Introduction. Tick-borne infections are of great importance for many regions of Russia, including Eastern Siberia. This unfavorable epidemiological situation can be characterized not only by the circulation of well-known tick-borne infections, but also by the identification of new pathogens, the role of which remains little or generally unexplored. Multicomponent flavi-like viruses can cause infectious diseases in humans and pose a threat to public health. The purpose of the study was the identification and molecular genetic characterization of the Alongshan virus (Flaviviridae, ALSV) isolates, transmitted by ticks in the south of Eastern Siberia. Materials and methods. Total 1060 ticks were collected and analyzed from the territory of the Republics of Khakassia, Tuva, Buryatia, Irkutsk Region and Transbaikal Territory (Zabaykalsky Krai) in the spring-summer period 2023. ALSV RNA was detected by RT-PCR followed by nucleotide sequence determination and phylogenetic analysis for each segment of the genome. Results. The ALSV infection rate in Ixodes persulcatus ticks collected in the Republic of Khakassia was 3.3% (95% CI: 1.4–7.5); in Irkutsk Oblast – 1.0% (95% CI: 0.3–3.7); in the Republic of Tuva – 0.9% (95% CI: 0.3–3.4) and in Transbaikal Krai – 0.7% (95% CI: 0.2–3.6). Sequences of all four segments of ALSV genetic variants circulating in I. persulcatus ticks in the south of Eastern Siberia are grouped with sequences found in China and clustered into the Asian subgroup transmitted by taiga ticks. The level of difference in the nucleotide sequences of genome fragments among the identified genetic variants of ALSV ranged from 2 to 3%. Conclusion. The article shows the widespread distribution of ALSV in I. persulcatus ticks in the Republics of Khakassia and Tyva, Irkutsk Oblast and Transbaikal Territory. The obtained data actualize monitoring of changes in the area of distribution of potentially dangerous for humans flavi-like viruses and their vectors.

Aim – to find regular patterns in the morphometric characteristics for the bodies of the cervical vertebrae when performing measurements in the axial (transverse) plane in men and women with different severity of degenerative-dystrophic changes of the cervical spine. Material and methods. The material of the study was the tomograms of 75 men and 128 women aged 18 to 84 years, obtained on magnetic resonance tomographs with a magnetic field strength of 1 Tl and 1.5 Tl. The data was divided into several groups according to the patients' sex and severity of degenerative-dystrophic changes of the cervical spine. The length and width of the vertebral bodies in the axial plane were measured with the subsequent calculation of their ratio. Results. Significant differences were found between the 1st and 2nd groups for the width of C7-C4 in women, as well as for the length of C3 and width of C3, C2 in men. Significant difference in the ratio of the sizes of vertebral bodies was registered in the 1st and 2nd groups of women at the level of C7. When comparing the data of all observation groups among men, significant differences were noted in the 2nd and 3rd groups for C7, C6, C3. With progression of degenerative-dystrophic changes, the differences in length were significant for C7-C4, C2 vertebrae in the 1st group, for C7-C5, C2 – in the 2nd and C7, C6, C4-C2 in the 3rd group. In the group of men with pronounced changes in the cervical spine region, in most cases there was an increase in coefficients (with significant differences in data for the 2nd and 3rd groups). Conclusion. Among men, significant differences were observed between the 2nd and 3rd groups for C7, C6, C3. For the C2 vertebra, significant differences were noted, taking into account sex, for length in the 1st and 3rd groups, width – in the 1st and 2nd groups, when assessing the mutual ratio of the sizes of the vertebral bodies – in the 2nd and 3rd groups.

To meet global food demands sustainably, it is necessary to safeguard finite natural resources and reduce harmful emissions to the environment. Nutrients in biowastes are often not managed appropriately. Instead, they can be recovered, recycled into bio-based fertilizers (BBFs) and reincorporated into food production systems. This review addresses three critical issues for developing and adopting new BBFs, focusing on the European context: (1) BBFs should match the agronomic efficiency of mineral fertilizers. We propose that the agronomic efficiency of BBFs can be increased through pre-treating the inputs in biowaste transformation processes (e.g., anaerobic digestion), chemical treatments of existing BBFs, organo-mineral combinations, and soil placement strategies. (2) Production and use of new BBFs is not free of environmental impacts, and these are influenced by regional conditions. (3) Public perception and end-user preferences play a significant role in the adoption of BBFs. Therefore, it is vital to address the requirements of end-users of BBFs. Our findings indicate that for widespread adoption, BBFs need sufficient and reliable nutrient amounts and crop-adequate ratios, as well as competitive pricing. A key advantage of BBFs over mineral fertilizers is their ability to improve soil fertility. However, farmers also require fertilizers that can be handled and applied with existing machinery and offer the practicality of commercial products. Another important aspect is the willingness of consumers to buy products fertilized with BBFs. Designing and promoting BBFs requires a careful assessment of environmental impacts and regional conditions, as the sustainability of BBFs depends on factors like energy sources and biowaste transport distances. Ultimately, the goal is to promote a circular economy and not just to substitute mineral fertilizers with new products. This review aims to guide researchers, policymakers, and stakeholders by highlighting key innovations and addressing critical barriers.

Bats are natural reservoirs for many emerging viruses, including coronaviruses that were probably progenitors to human coronaviruses with epidemic and pandemic potential, which highlights the importance of screening studies of bat-derived viruses. This study investigates the prevalence and phylogenetic characteristics of coronaviruses in bat populations from the Rostov and Novosibirsk regions of Russia between 2021 and 2023. Utilizing PCR screening and sequencing, viruses belonging to the Alphacoronavirus genus were detected in several bat species, with prevalence rates ranging from 4.94% to 62.5%. Phylogenetic analysis of detected sequences revealed the presence of three subgenera: Pedacovirus, Myotacovirus, and Nyctacovirus. These sequences shared over 90% identity with alphacoronaviruses previously identified in bats across Northern Europe and Russia, underscoring the viruses’ wide geographic distribution and evolutionary connections. The results highlight the adaptability of alphacoronaviruses and the role of bat migratory behavior in their dispersal. The study underscores the importance of continuous monitoring and phylogenetic studies of bat-derived coronaviruses to better understand their ecological dynamics and potential zoonotic threats.

Abstract Population density is known to affect the health and survival of many species, and is especially important for social animals. In mice, living in crowded conditions results in the disruption of social interactions, chronic stress, and immune and reproductive suppression; however, the underlying mechanisms remain unclear. Here, we investigated the role of chemosignals in the regulation of mouse physiology and behavior in response to social crowding. The pheromone 2,5-dimethylpyrazine (2,5-DMP), which is released by female mice in crowded conditions, induced aversion, glucocorticoid elevation and, when chronic, resulted in reproductive and immune suppression. 2,5-DMP olfaction induced genome destabilization in bone marrow cells in a stress-dependent manner, providing a plausible mechanism for crowding-induced immune dysfunction. Interestingly, the genome-destabilizing effect of 2,5-DMP was comparable to a potent mouse stressor (immobilization), and both stressors led to correlated expression changes in genes regulating cellular stress response. Thus, our findings demonstrate that, in mice, the health effects of crowding may be explained at least in part by chemosignals and also propose a significant role of stress and genome destabilization in the emergence of crowding effects.

Aim to evaluate the correlation between the course of vertebral arteries and veins and the results of calculations of hemodynamic parameters during ultrasound with functional tests. Material and methods. In the observation, 252 volunteers were examined using Samsung SonoAce R7 and GE Logiq F6 equipment. The hemodynamics was studied at the level of the second segment of the vertebral arteries and veins at rest, when turning, tilting and lifting the head. The results were processed using Microsoft Excel 2007 with subsequent statistical analysis. Results. 504 vascular complexes were analyzed without taking into account the visualization side. When assessing the arteries, the highest maximum blood flow velocity was registered when lifting the head in women with a rectilinear course of the vessels. In the group of men with non-rectilinear course of vessels, the lowest average blood flow velocity was registered when tilting the head. The highest volume flow was recorded in case of non-rectilinear vascular course in women when lifting the head. For vertebral veins, the highest indicators of maximum and minimum venous blood flow rates were observed in men with a rectilinear course of vessels when lifting the head. The highest values of the average flow velocity and volume flow were noted in men who had a rectilinear course of the vessels. The maximum values of the calculated venous volume flow were registered in groups with rectilinear vascular course: in men up to 19.4214.85 ml/min. (Me 12.45 ml/min.), in women 18.52 15.30 ml/min. (Me 10.50 ml/min.). Conclusion. The data obtained by the study contributes to improving the software and analysis of individual changes during patient examination, helps to evaluate the effectiveness of treatment and rehabilitation, as well as to analyze multifactorial models.

Sexual selection is considered as one of the leading factors of evolutionary development. In the conditions of incessant competition, specialized methods of attracting individuals of the opposite sex as well as criteria for assessing the quality of a sexual partner have been formed. In order for animals to rely on signaling from sexual partners, the signal must reflect the morpho-physiological status of animals. A high reproductive efficiency of male mice is a good advantage for mate selection and thus must be somehow demonstrated to potential mates. The aim of our study was to find out if male mice could demonstrate their reproductive efficiency through urine volatile organic compounds. The experiment implies cohabiting one male with two mature females for 6 days. The reproductive success of the male was assessed by the presence or absence of pregnant females. At the same time, naive females, who did not participate in reproduction, assessed the urine of the successful males as more attractive, which was expressed in shorter Latency time of sniffs in the Olfactory test. Using a rapid headspace GC/MS analysis, we have found volatile organic compounds (VOCs) in male urine that correlated with female behavior. It turned out that these substances are derivatives of mouse pheromone 6-hydroxy-6-methyl-3-heptanone. The amplitude of peaks corresponding to this pheromone correlated with the testosterone level in blood and the weight of preputial glands. The amplitude of peaks increased in males after mating with whom the females turned out to be pregnant. It is important to note that body weight, weight of testes, weight of seminal vesicles, weight of preputial glands, and plasma testosterone level alone are not reliable indicators of male reproductive success. Thus, the content of the pheromone 6-hydroxy-6-methyl-3-heptanone in the urine of males can serve as a good predictor of the quality of the male as a sexual partner for female CD-1 mice.

Increasing the activity of zoophage Acari in agrocenoses, for example luring them to concentrations of harmful insects, could be effectively performed using attractants, for example organic acids that people use in households and industry. In our experiment, we studied the influence of organic acids on the locomotor activity of Stratiolaelaps scimitus (Womersley, 1956) (Mesostigmata, Laelapidae). Different organic acids caused certain reactions in those zoophages. Acetic acid encouraged this mite to activity and attracted it, while thioacetic acid inhibited and repelled it. Fatty acids such as tridecylic and oleic acids had an activating effect on the locomotor activity of S. scimitus. Three isomers of valeric acid inhibited locomotor activity, and the mites exerted negative chemostasis to them. Maximum locomotor activity of the mites was observed when using asparagine, ornithine, propionic acid, tridecanoic acid, boric acid, and arginine. Locomotor activity of the mites was inhibited by 3,3-dimethylbutanoic acid, thioacetic acid, pivalic acid, maleic acid, formic acid, succinic acid, 2-methylbutanoic acid, isovaleric acid, 6-aminohexanoic acid, and 2-oxoglutaric acid. We propose using attractiveness coefficient and coefficient of migratory activity, which reflect the effects of aroma compounds on mites. Those coefficients are helpful in identification of a behaviour model for mites exposed to aroma compound: attack, motionless state or escape. High attractiveness and migratory-activity coefficients mean attack on victim; low coefficients indicate motionless mites; high migratory activity and low attractiveness coefficient mean escape reaction. Our results indicate complexity of behaviour reactions of mites, which were sensitive to volatile chemical compounds in the environment. We found a high potential of using those compounds in attracting zoophages during their introduction in agrocenoses of greenhouses and open plots.

To identify body systems subject to epigenetic transformation during in vitro fertilization (IVF), comparative morphological and functional studies were performed on sexually mature offspring of outbred CD1 mice, specific-pathogen-free (SPF), obtained by IVF (experiment) and natural conception (control). The studies included assessment of age-related changes in body weight and composition, energy intake and expenditure, and glucose homeostasis. To level the effects caused by the different number of newborns in the control and in the experiment, the size of the fed litters was halved in the control females. Males obtained using the IVF procedure were superior in body weight compared to control males in all age groups. As was shown by analysis of variance with experiment/control factors, gender, age (7, 10 and 20 weeks), the IVF procedure had a statistically significant and unidirectional effect on body composition. At the same time, IVF offspring outperformed control individuals in relative fat content, but were behind in terms of lean mass. The effect of the interaction of factors was not statistically significant. IVF offspring of both sexes had higher fat to lean mass ratios (FLR). Since adipose tissue contributes significantly less to total energy intake compared to muscle, the main component of lean mass, it is not surprising that at the same level of IVF locomotor activity offspring consumed less food than controls. When converted to one gram of body weight, this difference reached 19 %. One of the consequences of reduced utilization of IVF energy substrates by offspring is a decrease in their tolerance to glucose loading. The integral criterion for the effectiveness of restoring the initial glucose level is the area under the curve (AUC), the value of which was 2.5 (males) and 3.2 (females) times higher in IVF offspring compared to the corresponding control. Thus, the totality of our original and literature data shows an increase in the risk of metabolic disorders in IVF offspring, which is confirmed by epidemiological studies of a relatively young cohort of people born using assisted reproductive technologies.

Bats are natural reservoirs for many emerging viruses, including coronaviruses that were probably progenitors to human coronaviruses with epidemic and pandemic potential, which highlights the importance of screening studies of bat-derived viruses. This study investigates the prevalence and phylogenetic characteristics of coronaviruses in bat populations from the Rostov and Novosibirsk regions of Russia between 2021 and 2023. Utilizing PCR screening and sequencing, viruses belonging to the Alphacoronavirus genus were detected in several bat species, with prevalence rates ranging from 4.94% to 62.5%. Phylogenetic analysis of detected sequences revealed the presence of three subgenera: Pedacovirus, Myotacovirus, and Nyctacovirus. These sequences shared over 90% identity with alphacoronaviruses previously identified in bats across Northern Europe and Russia, underscoring the viruses' wide geographic distribution and evolutionary connections. The results highlight the adaptability of alphacoronaviruses and the role of bat migratory behavior in their dispersal. The study underscores the importance of continuous monitoring and phylogenetic studies of bat-derived coronaviruses to better understand their ecological dynamics and potential zoonotic threats. [ABSTRACT FROM AUTHOR]

Currently, direct surveys are used less and less to assess satisfaction with the quality of user services. One of the most effective methods to solve this problem is to extract user attitudes from social media texts using natural language text mining. This approach helps to obtain more objective results by increasing the representativeness and independence of the sample of service consumers being studied. The purpose of this article is to improve existing methods and test a method for classifying Russian-language text reviews of patients about the work of medical institutions and doctors, extracted from social media resources. The authors developed a hybrid method for classifying text reviews about the work of medical institutions and tested machine learning methods using various neural network architectures (GRU, LSTM, CNN) to achieve this goal. More than 60,000 reviews posted by patients on the two most popular doctor review sites in Russia were analysed. Main results: (1) the developed classification algorithm is highly efficient—the best result was shown by the GRU-based architecture (val_accuracy = 0.9271); (2) the application of the method of searching for named entities to text messages after their division made it possible to increase the classification efficiency for each of the classifiers based on the use of artificial neural networks. This study has scientific novelty and practical significance in the field of social and demographic research. To improve the quality of classification, in the future, it is planned to expand the semantic division of the review by object of appeal and sentiment and take into account the resulting fragments separately from each other.

Stratiolaelaps scimitus (Womersley, 1956) (Acari, Mesostigmata, Laelapidae) is a predatory soil mite massively produced in laboratories in many countries of the world. The existing spheres of S. scimitus application vary in many parameters, especially temperature and relative humidity. In this article, we analyzed temperature and humidity appropriate for fastest spread of soil predatory mite S. scimitus. Mites should be released to a new environment in such a way that they would distribute in a greenhouse, garden or field as fast as they can (i.e. providing maximum migration activity of S. scimitus), on the one hand, and provide maximum efficient control of number of target phytophage species (i.e. providing maximum trophic activity), on the other hand. In our experiment, at 14 ºC temperature, most specimens of S. scimitus did not leave the migratory circle for 10 seconds. In 15–19 ºC range, only 14.7% of mites left the migratory circle, and their examined activity in 10 s was only 5–10 mm. In 20–24 ºC range, 27.5% of mites left the migratory circle, their migratory activity increased to 15–23 mm. In 25–33 ºC range, the moving activity increased even more, the mites left the migratory circle at the first opportunity that had (some even jumped off the circle to the experimental field), 95.8% of the mites left the circle in 10 s, their examined activity reached 25–60 mm in 10 seconds. Study of thermo- and hygro-preferences for various groups of invertebrates helps to better describe their ecological niche in multidimensional space of ecologic factors.

The current status of the theoretical investigation of the bound-electron g factor in lithium-like and boron-like highly charged ions is reported. Some tension between the several theoretical values and measurements is discussed. Then, prospects for future investigations are briefly reviewed.

Abstract Finding novel biomarkers for human pathologies and predicting clinical outcomes for patients is challenging. This stems from the heterogeneous response of individuals to disease and is reflected in the inter-individual variability of gene expression responses that obscures differential gene expression analysis. Here, we developed an alternative approach that could be applied to dissect the disease-associated molecular changes. We define gene ensemble noise as a measure that represents a variance for a collection of genes encoding for either members of known biological pathways or subunits of annotated protein complexes and calculated within an individual. The gene ensemble noise allows for the holistic identification and interpretation of gene expression disbalance on the level of gene networks and systems. By comparing gene expression data from COVID-19, H1N1, and sepsis patients we identified common disturbances in a number of pathways and protein complexes relevant to the sepsis pathology. Among others, these include the mitochondrial respiratory chain complex I and peroxisomes. This suggests a Warburg effect and oxidative stress as common hallmarks of the immune host–pathogen response. Finally, we showed that gene ensemble noise could successfully be applied for the prediction of clinical outcome namely, the mortality of patients. Thus, we conclude that gene ensemble noise represents a promising approach for the investigation of molecular mechanisms of pathology through a prism of alterations in the coherent expression of gene circuits.

The lack of organs for transplantation is an important problem in medicine today. The growth of organs in chimeric animals may be the solution of this. The proposed technology is the interspecific blastocyst complementation method in combination with genomic editing for obtaining “free niches” and pluripotent stem cell production methods. The CRISPR/Cas9 method allows the so-called “free niches” to be obtained for blastocyst complementation. The technologies of producing induced pluripotent stem cells give us the opportunity to obtain human donor cells capable of populating a “free niche”. Taken together, these technologies allow interspecific blastocyst complementation between humans and other animals, which makes it possible in the future to grow human organs for transplantations inside chimeric animals. However, in practice, in order to achieve successful interspecific blastocyst complementation, it is necessary to solve a number of problems: to improve methods for producing “chimeric competent” cells, to overcome specific interspecific barriers, to select compatible cell developmental stages for injection and the corresponding developmental stage of the host embryo, to prevent apoptosis of donor cells and to achieve effective proliferation of the human donor cells in the host animal. Also, it is very important to analyze the ethical aspects related to developing technologies of chimeric organisms with the participation of human cells. Today, many researchers are trying to solve these problems and also to establish new approaches in the creation of interspecific chimeric organisms in order to grow human organs for transplantation. In the present review we described the historical stages of the development of the blastocyst complementation method, examined in detail the technologies that underlie modern blastocyst complementation, and analyzed current progress that gives us the possibility to grow human organs in chimeric animals. We also considered the barriers and issues preventing the successful implementation of interspecific blastocyst complementation in practice, and discussed the further development of this method.

Assisted reproductive technologies (ART) increasingly occupy the study of human reproduction. In addition, in developed countries they contribute to breeding of more than 50 % of cattle. In the management of collections of genetic lines of laboratory animals, these technologies are obligatory components of cryopreservation and rederivation. ART procedures include the development of early embryos outside the mother’s body and the high probability of incomplete synchronization of the physiological state of the surrogate mother and transplanted embryos. Since all this occurs at the stage of the highest susceptibility of embryos to epigenetic reprogramming, the full cycle of ART and its individual components can lead to stable phenotypic changes in the offspring. Their reality is confirmed by studies of the morphological and functional characteristics of sexually mature offspring of CD1 outbred mice, obtained using different variants of early embryo transplantation. Comparative studies of body mass and body composition, basal glucose level and response to glucose load (glucose-tolerance test – GTT) have been done on sexually mature males and females. Animals were separated in 4 groups according to the variant of embryo transplantation: group (control) – natural mating; group (2cl-bl) – incubation of 2-cell up to blastocysts; group (2cl-2cl) – removal and transplantation of the 2-cell embryo without incubation; group (Bl-bl) removal and transplantation of the blastocysts without incubation. All embryos were transplanted to recipient females of the same line. It was found that sexually mature offspring obtained with all variants of transplantations had a higher relative fat content and, correspondingly, lower lean mass compared to the control. This effect was more pronounced in females than in males. Unlike body compositions, embryo transplantations had a greater effect on basal glucose concentration and GTT in males than in females. In this case, the offspring of the 2cl-2cl and 2cl-bl groups were characterized by a higher tolerance to glucose load (GTT) compared with the control and the Bl-bl group. Stable deviations of body compositions and glucose homeostasis indices detected in experimental groups of progenies indicate the phenotypic significance of the embryo transplantations per se.

Background: Q fever is a zoonotic infectious disease characterized by fever, malaise, chills, significant weakness, and muscle pain. In some cases, the disease can become chronic and affect the inner membranes of the heart, such as the valves, leading to endocarditis and a high risk of death. Coxiella burnetii (C. burnetii) is the primary causative agent of Q fever in humans. This study aims to monitor the presence of C. burnetii in ticks collected from small mammals and cattle in the Republic of Guinea (RG). Methods: Rodents were trapped in the Kindia region of RG during 2019–2020, and ticks were collected from cattle in six regions of RG. Total DNA was extracted using a commercial kit (RIBO-prep, InterLabService, Russia) following the manufacturer’s instructions. Real-time PCR amplification was conducted using the kit (AmpliSens Coxiella burnetii-FL, InterLabService, Russia) to detect C. burnetii DNA. Results and Conclusions: Bacterial DNA was detected in 11 out of 750 (1.4%) small mammals and 695 out of 9620 (7.2%) tick samples. The high number of infected ticks (7.2%) suggests that they are the main transmitters of C. burnetii in RG. The DNA was detected in the liver and spleen of a Guinea multimammate mouse, Mastomys erythroleucus. These findings demonstrate that C. burnetii is zoonotic in RG, and measures should be taken to monitor the bacteria’s dynamics and tick prevalence in the rodent population.