Newborn Animals Research Articles

Cattle stock (Bos taurus) in Yeniseysk (Krasnoyarsk Krai) in the 18th–19th centuries

As a result of the large-scale rescue excavations on the territory of the town of Yeniseysk (58°27'N, 92°10'E) in Eastern Siberia, a large osteological collection has been assembled. In this study, cattle bone remains from the excavations on the territory of the architectural complex ‘Balandin mansion’ have been analysed. The deposits of the mansion span both the initial period of settlement in Yeniseysk, almost from the moment of its foundation, as well as the late period — the end of the 19th century. The focus of the livestock production in the 17th–19th cen-turies in Yeniseysk was cattle breeding. The sex and age structure of the herd and size of the body of the animals have been reconstructed using special techniques from the parameters of the lower jaws and size of the metatar-sal, metacarpal, and talus bones, as well as the first phalanges. On this basis, the breed characteristics and cases of economic use of the cattle have been described. The presence of a large percentage of newborn ani-mals indicates that the cattle were kept within the town territory. Some amount of beef was imported to Yeniseysk as a result of the trade with indigenous cattle farmers. The reconstructed age and sex structure, where about 50 % of animals are cows older than 4 years, while the proportion of young animals among the slaughtered stock does not exceed 40 %, indicates the meat-and-dairy use of the cattle. The livestock was predominantly horned, and the polledness was not pronounced. Yeniseysk livestock had an average body size. The cattle in Yeniseysk were bigger than those of the Russian population in the forest belt of the European part of Russia. The sizes of cattle from other Russian cities in Siberia are identical to the Yenisei cattle. With a high degree of probability, the de-scribed breed can be attributed to the Siberian cattle, which were widespread on the territory of Siberia, the Urals, and the Far East.

Metabolome, microbiome, and gene expression alterations in the colon of newborn piglets with intrauterine growth restriction.

Newborn animals with intrauterine growth restriction (IUGR) are characterized by impaired intestinal structure and function; however, their intestinal microbiota and metabolome profiles have not been fully identified. The present study investigated the differences in colonic microbiota, metabolomics, and barrier function-related gene expression profiles between the IUGR and normal birth weight (NBW) piglets at 7, 21, and 28 days of age. Forty-eight piglets (24 NBW and 24 IUGR) from 24 litters were assigned to assess the differences in colonic microbiota, metabolomics, and gene expression between IUGR and NBW piglets. Compared with the NBW piglets, IUGR piglets showed decreased Shannon index and increased Simpson index at 7 days of age and Chao1 index at 21 days of age (p < 0.05). The IUGR piglets had lower abundances of Firmicutes, Subdoligranulum, Ruminococcaceae_UCG-002, and Ruminococcaceae_UCG-003 at 7 days of age, and Bacteroidetes, Phascolarctobacterium, and Ruminococcaceae_UCG-005 at 21 days of age, when compared with the NBW piglets (p < 0.05). Metabolomics analysis showed significant changes in 147 metabolites mainly involved in organic acids and their derivatives in the colon. Six differential metabolic pathways were significantly enriched, including purine metabolism, amino sugar/nucleotide sugar metabolism, ubiquinone/other terpenoid-quinone biosynthesis, phenylalanine/tyrosine/tryptophan biosynthesis, phenylalanine metabolism, and histidine metabolism. Spearman’s correlation analysis further demonstrated significant correlations between colonic microbiota and metabolites. In addition, colonic isobutyrate at 7 days of age, isovalerate and total short-chain fatty acids (SCFAs) at 21 days of age, and acetate, propionate, butyrate, and total SCFAs levels at 28 days of age were lower and isovalerate was higher at 28 days of age in the IUGR piglets than in the NBW piglets (p < 0.05). Furthermore, the mRNA expression of zonula occludens (ZO)-1 at 7 days of age, ZO-1, occludin, and interleukin (IL)-4 at 21 days of age were down-regulated in the IUGR piglets, whereas tumor necrosis factor (TNF)-α and nuclear factor-kappa B (NF-κB) at 28 days of age were up-regulated, when compared with the NBW piglets (p < 0.05). The findings suggest that the IUGR pigs present abnormal microbiota and nutrient metabolism in the colon, which may further affect the intestine barrier function by regulating gene expressions.

Alterations in The Functional and Structural Properties of Erythrocytes Due to Alcohol Intoxication; Correction of Disorders

Alcohol abuse is among the leading reasons for disability and accounts for at least 5% of the global health burden. This study aims to define changes in the functional and structural properties of erythrocytes in chronic ethanol intoxication and to design methods for correction of the identified disorders. The experiments has been conducted on 93 healthy sexually mature and newborn Wistar rats. Acute and chronic alcohol intoxication has been designed by forced intragastric administration of 20% ethanol solution at a dose of 3 ml/kg (2.92 g/kg) on a daily basis for 5, 30 and 60 days. From the newborn animals we obtained allogeneic hepatocytes and their cultural fluid, from which proteins were isolated. The proteins of allogeneic hepatocyte and the combined administration of immunomodulatory, hepatoprotective and antioxidant agents were used to correct disorders in chronic intoxication. The membranes of circulating erythrocytes were obtained by the method of Dodge; electrophoretic separation of membrane proteins was carried out according to the method of Laemli. The lipid content in the erythrocyte membrane was determined by liquid thin-layer chromatography. It has been elucidated that in presence of chronic alcohol intoxication there is a change in the content of the membrane proteins in circulating erythrocytes, which are responsible for flexibility and shaping, intrinsic cellular metabolism, stabilization and structure formation, and a disruption in the lipids representativeness and ratio that form the basis for the lipid framework of the plasmalemma and play the major role in arrangement of protein macromolecules and the normal metabolism of red blood cells as well. When analyzing the corrective activity of the proteins of allogeneic hepatocytes and the combination Glutoxim + Mexidol + Heptral, we have established their high efficiency towards the disorders in the functional and structural properties of circulating erythrocytes caused by chronic alcohol intoxication.

VARIABILITY OF SELECTION TRAITS IN COWS DEPENDING ON THE COUNTRY OF BULLS SELECTION

VARIABILITY OF SELECTION TRAITS IN COWS DEPENDING ON THE COUNTRY OF BULLS SELECTION

The content of immunoglobulins in the blood serum of mother cows with genital mycoplasmosis and calves born from them

The state of the immune system of newborn animals largely determines their further development, morbidity, and productive qualities. Various diseases of pregnant animals to a certain extent affect the body of the fetus, this is especially true if the disease is characterized by an erased clinical picture and it is difficult to diagnose it in a timely manner. One of these diseases is genital mycoplasmosis of cattle, which is widespread both in our country and abroad. Despite this, many aspects of the pathogenesis of genital mycoplasmosis remain poorly understood, especially the state of the immune system. A study was made of the content of immunoglobulin classes in healthy dry cows and cows with genital mycoplasmosis, as well as in calves born by them. The results showed a significant decrease in the level of immunoglobulins and a redistribution of their classes in cows with genital mycoplasmosis. Changes of a similar nature, but more pronounced, were also noted in calves born from these cows. Studies show that pregnant cows with genital mycoplasmosis develop an immunodeficiency state, characterized by a decrease in the total amount of immunoglobulins, a significant decrease in the level of Ig G and an increase in the concentration of Ig A. A similar immunodeficiency state was observed in calves obtained from these cows. The noted changes will be useful for the development of rational therapy for genital mycoplasmosis in cows.

Diagnosis and control of cryptosporidiosis in farm animals.

Cryptosporidium is a pathogenic protozoan parasite infecting the gastrointestinal epithelium of human and animal hosts. In farm animals, cryptosporidiosis causes significant economic losses including deaths in newborn animals, retarded growth, increased labor involved and high cost of drugs. The detection of Cryptosporidium oocysts in fecal samples is traditionally dependent on examination of stained slides by light microscope or by advanced microscopical tools such as: electron microscopy and phase contrast microscopy. Immunological diagnosis using either antibody or antigen detection could offer high sensitivity and specificity. Examples for these tests are Enzyme Linked Immunosorbent Assay (ELISA), Immunochromatographic tests, Immunochromatographic lateral flow (ICLF), Immunofluorescence assays (IFA) and Flow cytometry coupled with cell sorting. Molecular methods could differentiate species and genotypes of Cryptosporidium and help in studying the epidemiological features of this parasite with rapid, simple and sensitive procedures. Nanotechnology-based platforms could improve the sensitivity and specificity of other detection methods like: ELISA, ICLF, IFA and polymerase chain reaction. As the available prophylactic and therapeutic drugs or natural products treatments are insufficient and no approved vaccines are available, the best approach to control this parasite is by following firm hygienic measures. Many vaccine attempts were performed using hyperimmune colostrum, live or attenuated vaccines, recombinant and Deoxyribonucleic acid vaccines. Also, Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 technology could help in Cryptosporidium genome editing to improve drug and vaccine discovery. Another approach that could be useful for assigning drug targets is metabolomics. Probiotics were also used successfully in the treatment of acute diarrhea and they proved a limiting effect on cryptosporidiosis in animal models. In addition, nanotherapy-based approaches could provide a good strategy for improving the potency of any type of drugs against Cryptosporidium and give good anti-cryptosporidial effects. In conclusion, accurate diagnosis using advanced techniques is the key to the control and prevention of cryptosporidiosis.

Role of Lateral Inhibition on Visual Number Sense.

Newborn animals, such as 4-month-old infants, 4-day-old chicks, and 1-day-old guppies, exhibit sensitivity to an approximate number of items in the visual array. These findings are often interpreted as evidence for an innate “number sense.” However, number sense is typically investigated using explicit behavioral tasks, which require a form of calibration (e.g., habituation or reward-based training) in experimental studies. Therefore, the generation of number sense may be the result of calibration. We built a number-sense neural network model on the basis of lateral inhibition to explore whether animals demonstrate an innate “number sense” and determine important factors affecting this competence. The proposed model can reproduce size and distance effects of output responses of number-selective neurons when network connection weights are set randomly without an adjustment. Results showed that number sense can be produced under the influence of lateral inhibition, which is one of the fundamental mechanisms of the nervous system, and independent of learning.

Peculiarities of nutrient metabolism in the body of a purebreed and mixed young cattle

Relevance. With the organization of optimal conditions for keeping and full-fledged, balanced feeding, a more complete realization of the bioresource potential of meat productivity is possible. Interbreeding contributes to the production of crossbred young animals, which, due to enriched heredity, have the potential for intensive growth and achieving a high level of meat productivity.Methods. For the study, 3 groups of bulls of the following genotype were formed from newborn young animals: I — Kazakh white-headed, II — 1/2 Hereford x 1/2 Kazakh white-headed, III — 3/4 Kazakh white-headed x 1/4 Hereford.Results. It was established that due to a more significant manifestation of the effect of crossing, the crossbred bulls of the II group (1/2 Hereford x 1/2 Kazakh whitehead) were superior to the crossbred peers of the III group (3/4 Kazakh whitehead x 1/4 Hereford) in the consumption of all types of nutrients. It is suffice to say that this advantage in dry matter intake was 98.9 g (1.1%), organic matter — 87.9 g (1.1%), crude protein — 18.8 g (1.4%), crude fat — 3.8 g (1.3%), crude fiber — 28.2 g (1.4%), nitrogen-free extractives — 37.1 g (0.9%). The obtained experimental data indicate the influence of the genotype of young animals on the value of the coefficient of digestibility of nutrients in the diet. At the same time, crossbred bulls of groups II and III better than purebred peers of the Kazakh white-headed breed used the nutrients of the feed diet that entered the body. This is evidenced by the value of the coefficient of their digestibility. It was found that the maximum consumption of all types of energy was characterized by crossbred half-blooded (1/2 Hereford x 1/2 Kazakh white-headed) bulls of group II.

Prenatal Low-Protein and Low-Calorie Diets Differentially Alter Arcuate Nucleus Morphology in Newborn Male Rats.

BackgroundMalnutrition during the early stages of development produces alterations that can compromise the functioning of the hypothalamic circuits that regulate food intake. The purpose of this study is to analyze the effects that a low-protein and low-calorie diet has on the morphology of the arcuate nucleus (ARC) of the hypothalamus in newborn male and female rats.MethodsOn gestational day 6 (G6), six pregnant rats were divided into two groups. One group was made up of three pregnant rats, which were fed ad libitum with a control diet (20% casein), and the other one was made up of three pregnant rats, which were fed ad libitum with a low-protein diet (8% casein) and 30% of a calorie-restricted diet. On the day of birth, pups were sacrificed, resulting in four experimental groups: control male, control female, low-protein and low-calorie diet male, and low-protein and low-calorie diet female (n = 5 in each group). The volume and number of neurons, together with the neuronal density and number of apoptotic cells, were measured.ResultsMales on a low-protein and low-calorie diet showed a significant increase in the number of neurons and in the neuronal density of the ARC with regard to the rest of the groups studied. These increases were also reflected in the posterior part of the nucleus. Although the existence of sexual dimorphism was not detected in any of the parameters studied in the control groups, the number of neurons and neuronal density showed differences between males and females fed with a low-protein and low-calorie diets due to the increase in the number of neurons shown by the male. No significant differences were found in the number of apoptotic cells.ConclusionOur results show that a low-protein and low-calorie diet during the prenatal stage produces alterations in the ARC of the hypothalamus in newborn animals and, more importantly, that the effects of malnutrition are evident in males but not in females. Therefore, it is essential to follow a balanced diet during the early stages of life to ensure optimal development of the neural circuits that regulate eating.

Epinephrine vs placebo in neonatal resuscitation: ROSC and brain MRS/MRI in term piglets.

We aimed to investigate the effect of epinephrine vs placebo on return of spontaneous circulation (ROSC) and brain magnetic resonance spectroscopy and imaging (MRS/MRI) in newborn piglets with hypoxic cardiac arrest (CA). Twenty-five piglets underwent hypoxia induced by endotracheal tube clamping until CA. The animals were randomized to CPR + intravenous epinephrine or CPR + placebo (normal saline). The primary outcome was ROSC, and secondary outcomes included time-to-ROSC, brain MRS/MRI, and composite endpoint of death or severe brain MRS/MRI abnormality. ROSC was more frequent in animals treated with epinephrine than placebo; 10/13 vs 4/12, RR = 2.31 (95% CI: 1.09-5.77). We found no difference in time-to-ROSC (120 (113-211) vs 153 (116-503) seconds, p = 0.7) or 6-h survival (7/13 vs 3/12, p = 0.2). Among survivors, there was no difference between groups in brain MRS/MRI. We found no difference in the composite endpoint of death or severe brain MRS/MRI abnormality; RR = 0.7 (95% CI: 0.37-1.19). Resuscitation with epinephrine compared to placebo improved ROSC frequency after hypoxic CA in newborn piglets. We found no difference in time-to-ROSC or the composite endpoint of death or severe brain MRS/MRI abnormality. In a newborn piglet model of hypoxic cardiac arrest, resuscitation with epinephrine compared to placebo improved the rate of return of spontaneous circulation and more than doubled the 6-h survival. Brain MRS/MRI biomarkers were used to evaluate the effect of epinephrine vs placebo. We found no difference between groups in the composite endpoint of death or severe brain MRS/MRI abnormality. This study adds to the limited evidence regarding the effect and safety of epinephrine; the lack of high-quality evidence from randomized clinical trials was highlighted in the latest ILCOR 2020 guidelines, and newborn animal studies were specifically requested.

Efficient and Fast Generation of Relevant Disease Mouse Models by In Vitro and In Vivo Gene Editing of Zygotes.

Knockout mice for human disease-causing genes provide valuable models in which new therapeutic approaches can be tested. Electroporation of genome editing tools into zygotes, in vitro or within oviducts, allows for the generation of targeted mutations in a shorter time. We have generated mouse models deficient in genes involved in metabolic rare diseases (Primary Hyperoxaluria Type 1 Pyruvate Kinase Deficiency) or in a tumor suppressor gene (Rasa1). Pairs of guide RNAs were designed to generate controlled deletions that led to the absence of protein. In vitro or in vivo ribonucleoprotein (RNP) electroporation rendered more than 90% and 30% edited newborn animals, respectively. Mice lines with edited alleles were established and disease hallmarks have been verified in the three models that showed a high consistency of results and validating RNP electroporation into zygotes as an efficient technique for disease modeling without the need to outsource to external facilities.

Comparative microscopic and electron microscopic study of somatotropic pituitary cells in two rare mammalian species

The aim of this study was to find out the microscopic and ultrastructural features of somatotropic endocrinocytes in two rare mammalian species in postnatal ontogenesis.Material and methods. We used material from river beavers (Castor fiber L.) and sea otters (sea beaver, Enhydra lutris), listed in the Red Book of the Russian Federation. The collection of material was carried out in the Voronezh Reserve and on the rookeries of marine mammals on the Commander Islands (Bering Island, Medny Island). To fix the material, Shteve, Bouin, and Zenker liquids were used. Paraffin sections were stained with hematoxylin and eosin, aldehyde fuchsin according to Helmi–Dyban. The linear dimensions of cell structures were measured, the cross-sectional area of cells and their nuclei was calculated, and the nuclear cytoplasmic index was calculated. The numerical density of somatotropic endocrinocytes in the field of view was determined. For electron microscopy, pituitary specimens were fixed in 2.5% glutaraldehyde and 1% osmium fixative. Sections were prepared on BS-490 and LKB-4800 ultramicrotomes. Sections were counterstained with uranyl acetate and lead citrate and studied under a Tesla BS-500 electron microscope.Results. In river beavers and sea otters at the age of 6 months, compared with newborn animals, the number of somatotropic cells in the center of the pituitary gland increases by 3.46 (p&lt;0.05) and 3.32 times (p&lt;0.05), respectively, and in the lateral zones – 2.61 times (p&lt;0.05) and 3.39 times (p&lt;0.05); cell cytoplasm area – 1.96 times (p&lt;0.05) and 1.85 times (p&lt;0.05); the area of the nuclei – 1.48 times (p&lt;0.05) and 1.30 times (p&lt;0.05). In river beavers and sea otters at the age of one year, compared with six-month-old animals, an increase in the number of somatotropic cells in the center of the pituitary gland by 1.27 times (p&lt;0.05) and 1.33 times (p&lt;0.05) was revealed; and in the lateral zones by 1.08 times (p&lt;0.05) and 1.02 times (p&gt;0.05); and area of the cytoplasm of cells, respectively – 1.29 times (p&lt;0.05) and. 1.25 times (p&lt;0.05). The maximum indicators of secretory activity of somatotropic cells were found in river beavers and sea otters at the age of 1 year.

Detection of Rift Valley Fever Virus in Aedes (Aedimorphus) durbanensis, South Africa

Rift Valley fever virus (RVFV) is a mosquito-borne, zoonotic phlebovirus-causing disease in domestic ruminants and humans in Africa, the Arabian Peninsula and some Indian Ocean islands. Outbreaks, characterized by abortion storms and a high morbidity rate in newborn animals, occur after heavy and prolonged rainfalls favouring the breeding of mosquitoes. However, the identity of the important mosquito vectors of RVFV is poorly known in most areas. Mosquitoes collected in the Ndumo area of tropical north-eastern KwaZulu-Natal (KZN), South Africa, were tested for RVFV nucleic acid using RT-PCR. The virus was detected in a single pool of unfed Aedes (Aedimorphus) durbanensis, indicating that this seasonally abundant mosquito species could serve as a vector in this area of endemic RVFV circulation. Phylogenetic analysis indicated the identified virus is closely related to two isolates from the earliest outbreaks, which occurred in central South Africa more than 60 years ago, indicating long-term endemicity in the region. Further research is required to understand the eco-epidemiology of RVFV and the vectors responsible for its circulation in the eastern tropical coastal region of southern Africa.

Humanized animals as models of experimental oncology (review)

The humanization of immunodeficient animals allows us to study the growth of xenografts of human malignant tumors and their response to therapeutic effects, taking into account processes in the immune system and tumor zone, which have a significant impact on oncogenesis and the effectiveness of antitumor therapy. Such experimental models are currently considered as the most advanced tool in the development of personalized antitumor treatment. The lines of immunodeficient animals most commonly used for the transplantation of mature and stem human immune cells have been characterized. The main sources of human immune cells when implementing the hu-pbl and hu-cd34+ models, as well as the blt model (as an option to the cd34+ model) are described. The basic procedures necessary for reproducing each model, their modification in adult and newborn animals are outlined as well as the parameters of immunosuppressive radiation exposure, preceding the transplantation of human hematopoietic stem cells. The main results of the humanization of immunodeficient animals and examples of the use of these models for the purposes of fundamental and clinical oncology are described. The main problems of this direction are discussed. The review is based on an analysis of the literature presented in the scopus, web of science, medline, risc and others databases over the past 7 years (over 80 % of literature sources, with more than over 50 % of studies published over the last 3 years).

Morphofunctional characteristics of animals in the detection of embryonic antigens in the prenatal and postnatal periods

Diseases in newborn animals cause significant damage to animal husbandry. This is a complex problem, in which, along with such factors as the environment and the pathogen, an important role is played by the reaction of the body of newborns and their close connection with the mother's body. The study of enzyme relationships in the functional system «mother-fetus-newborn» can make a significant contribution to solving the problem of improving the safety of the population of newborn animals. Newborn animals have different degrees of functional maturity. Functional capacity of some organs and the system of the newborn, in comparison with the parent individuals, can be determined both genetically and by the conditions of intrauterine development. Currently, a sufficient number of facts have been accumulated that any deviations or violations of homeostasis parameters the mother's body affects the fetus and Vice versa. The main role in compensating for impaired functions belongs to the mother's body, but the fetus is also able to participate in these reactions to a certain extent. Functional integration of fetal and maternal homologous systems when performing homeostatic functions concerns the activity of the blood enzyme component. The aim of our research was to study quantitative and qualitative changes in the activity of blood enzymes in non-pregnant sows, in the first and second half of pregnancy and the postpartum period.

Economic order quantity for growing items in the presence of mortality

Growth depicts the behavior of a class of inventories whose weight and size increase during their storage. Although the phenomenon is fundamental in the food industry, it still faces a lack of academic heed. Our research sheds new light on this area by illustrating the inventory system of a rearing farm that breeds fast-growing newborn animals (like broiler chickens) and finally slaughters them. The items are prone to different diseases during their growth which can lead to their death. This is modeled by applying a mortality rate that can be controlled by investing in preventive practices. The slaughtered items (such as chicken meat) that fall into the category of deteriorating inventory are quality controlled and exploited to satisfy demand. An analytic solution approach is developed to derive the optimal order quantity of newborn animals, their growth period, and action level for preventive practices. Experimental results show that choosing a hatchery with the best purchasing cost should be the first priority of the system to manage its costs. It is also depicted that the breeding period is not influenced by all input parameters of the model, and the nature of the items plays a key role in this regard.

Determination of prophylactic and therapeutic effectiveness of probiotic strain Escherichia coli 39-SN.

At present, it is relevant to preserve and raise healthy, well-developed newborn animals adapted to new conditions, which form the basis for increasing the yield of animal husbandry. Gastrointestinal diseases cause the main losses of young animals. Acute gastrointestinal diseases of calves, lambs, piglets, and chickens are widespread in Kazakhstan. The study aims to develop a competitive treatment and prophylactic drug composition based on probiotic bacterial strains. Modern certified and standardized biochemical, microbiological, molecular biological studies were considered during the research. The morphological, cultural, and biochemical properties of the cultures were studied according to generally accepted schemes. Standard methods of finding averages and their mean errors were used for the mathematical processing of results. Antibiotics, sulfonamide, and nitrofuran drugs are the most common methods to combat diseases in young animals. However, the use of antibacterial agents often leads to the death of normal microflora, disrupting the microbiocenosis of the gastrointestinal tract, the appearance of microorganisms with resistance to drugs, and a decrease in product quality. In this regard, the direction of biotechnology involved in the development and creation of environmentally friendly microbial preparations with prophylactic effectiveness is very relevant. Data on the prophylactic and therapeutic efficacy of the probiotic strain of Escherichia coli 39-SN are presented.

ASSESSMENT OF THE REPRODUCTIVE TOXICITY OF THE DRUG INTERAMIN WITHIN THE FRAMEWORK OF PRECLINICAL TRIALS

The article describes the results of an experimental study of the embryotoxic and teratogenic effects of the new combination drug interamin. The analysis of the data obtained indicates the absence of any negative effect on female white rats during the entire pregnancy when administered at the studied doses (0.1 ml/kg and 1.0 ml/kg), absence of induction of pre- and post-implantation death, total embryonic mortality, pathologies of organogenesis and development of the fetal skeletal system, disorders of postnatal development of newborn animals. Based on this, no signs of embryotoxic and teratogenic effects of interamin were detected.

Experimental studies on risk factors of necrotizing enterocolitis

Introduction. Necrotizing enterocolitis (NEC) is one of the most life-threatening conditions in the neonatal period. This disease is considered to be polyethiological one; however, the pattern of NEC pathogenesis is not clear yet. The aim of the present research is to study in details NEC risk factors and pathogenetic mechanisms in experiment.Material and methods. NEC was induced in 28 rat pups (breed: Wistar). Newborn animals (21-day gestation age) were labored from three female rats aged 9-12 months. In the research, the experimental animals were induced: hypoxia, inadequate formula feeding and bacterial contamination. The observation period lasted for 96 hours; the obtained results were assessed by the following criteria: clinical symptoms, mortality, intraoperative findings, histological findings and microbiological spectrum.Results. NEC clinical signs were seen both in subgroup 1A (animals had hypoxia and inadequate formula feeding) and in subgroup 1B (additionally, animals had microbial contamination). Clinical and morphological findings were more pronounced in subgroup 1B. Mortality in subgroup 1B was 50%. The histological picture in subgroup 1A corresponded to that of NEC stage 1A-2A and in subgroup 1B – to NEC stage 2B–3B (by Walsh and Kliegmann). In subgroup 1B, there was a massive intestinal colonization in the intestinal lumen.Conclusion. Hypoxia and inadequate formula feeding are, as such, risk factors of necrotizing enterocolitis. Additionally, bacterial aggression significantly worsens the course of necrotizing enterocolitis and its prognosis. However, the lack of bacterial component does not rule out NEC onset in newborns.

Current Methods for the Isolation and Cultivation of Microglia (Review).

The role and morphological features of microglia (M1 and M2 microglia, “stellate”, “amoeboid”, giant, round-shaped, rod-shaped, dysfunctional, etc.) in vivo under physiological conditions and during the development of neurodegenerative diseases have been described. Various methods and techniques of microglia isolation from adult (density gradient isolation, use of “magnetic beads”, from mesenchymal bone marrow progenitor cells) and newborn (obtaining from a mixed glial culture, density gradient isolation) animals have been considered, including microglia isolation from the cerebral cortex or hippocampus. Various methods of cell cultivation have been shown, including obtaining two-dimensional and three-dimensional cell cultures (on scaffolds, hydrogels, nanofibers), co-cultures on slice cultures of the hippocampus, as well as changes in microglia during cultivation.