The data on the concentration of structural proteins of plasmolemma of the absorption enterocytes of the cattle fetus in the early fetal period are presented. Changes in the protein composition of the apical and basolateral membranes of enterocytes are manifested, characterized not only by changes in their ratio within different cell domains, but also by the dynamic redistribution of the number of different fractions of polypeptides between the poles of these cells. Analysis of the results of electrophoresis of apical membranes of the cattle fetus enterocytes in the early fetal period indicates a decrease in the content of low molecular weight protein fractions and an increase in high molecular weight. In the apical membranes of enterocytes of two-month-old cattle fetus, 25 protein fractions with a molecular weight of 9.6 to 205 kDa were detected. In the basolateral membranes revealed 23 protein fractions with a molecular weight of 9.6 to 120 kDa. High molecular weight fractions of polypeptides with molecular weights of 250 kDa and 300 kDa appear from the age of three months of embryos of calves. In the basolateral membranes of enterocytes, there is a slight decrease in the content of low molecular weight protein fractions, and from the four months of age of cattle fetus, high molecular weight fractions of polypeptides with molecular weights of 22.5 kDa and 155 kDa appear, which are absent in basolateral membranes of enterocytes. Two-month-old fetus lack proteins with a molecular weight of 19 kDa, 24 kDa, and 66 kDa in the apical part, whereas proteins with a mass of 22.5 kDa, 155 kDa, 170–185 kDa, and 205 kDa are absent on the basolateral membrane. In the apical membrane of enterocytes significantly more proteins with a low molecular weight of 9.6-14.2 kDa (1.56 times; P ≤ 0.001), whereas in the basolateral membrane a significantly higher concentration of proteins with a molecular weight of 15.5 kDa (2.06 times; P ≤ 0.001) and 17 kDa (3.62 times; P ≤ 0.001).

Study of the emergent properties and paths of spreading of PEDV was carried out in a model experiment on newborn non-immune piglets obtained from a PED virus-free pig-breeding enterprise. The piglets were kept in separate specialized containers, with a volume of 1.0 m3, with access only through the opening at the top of the containers. The experimental group of the animals was infected with PEDV isolate extracted on one of the pig farms from the central region of Ukraine. Infection was carried out orally in a dose of 1–10 genome equivalents of virions. The control piglets, which were situated in the same room as the infected animals, were not deliberately infected. The study of biological material from piglets was carried out using the methods of bacteriology, histology and RT-PCR. To confirm the capability of PEDV to spread through house flies, specimens of Musca domestica vicina Mcq. were caught in the building where the experiment was carried out. The washings from the surface of their bodies were collected with sterile saline. Individually, 28 specimens of flies were selected. They were divided into two parts and the amount of virus in the homogenate of the fly bodies in these groups was determined with an interval between measurements of 72 hours. Study of PEDV in the washings and in flies body homogenates were carried out using RT-PCR. It is established that the field strain PEDV, belonging to the North American grouping II of the second group of the PED virus strains, is an emergent highly pathogenic agent for non-immune newborn piglets. In the model of piglets’ infection it is established that the tested PEDV strain has a high virulence for newborn piglets, DCL is 1–10 virions and the incubation period is 18–26 hours. PED is acute with lethality to 100% within 68–72 hours after infection. According to the results of RT-PCR in washing from the surface of the bodies of flies, it is established that one of the ways piglets are infected and the environment contaminated with the PED virus is the spread of the pathogen by the flies M. domestica vicina Mcq. This leads to the induction of the emergent form of PED in piglets. The presence of PEDV in the homogenate from bodies of M. domestica caught in the focus of infection and the absence of virus reproduction in their body confirms the role of the house fly in the mechanical spread of PEDV in the external environment.

Imidacloprid is the most widely used pesticide of the neonicotinoid class. Neonicotinoid toxicities against various insects are well known. Nevertheless, there are rising evidences that neonicotinoids exert cytotoxic effects on different non-target organisms including mammals, fish, birds etc. Besides, depending on pesticide application, the exposed plants absorb some part of used neonicotinoids and their residues are detected in agricultural products worldwide. Thus, the continuous consumption of fruits and vegetables contaminated with neonicotinoids is a high risk factor for humans despite the low doses. Intestine epithelial cells are the first targets of the neonicotinoid cytotoxicity in humans because of its direct way of administration. The epithelial cells provide the barrier function of the intestinal system via specialized intercellular adhesion. The effects of imidacloprid on the intestine barrier function and inflammatory cytokines production are still unknown. In the present study, we exposed the human Caucasian colon adenocarcinoma (Caco-2) epithelial cells to low doses (0.10–0.75 µg/mL) of imidacloprid in order to assess the expression of tight and adherens junctions proteins, occludin and E-cadherin, and production of proinflammatory cytokine TNF α and iNOS. Imidacloprid induced dose-dependent decline in both occludin and E-cadherin levels. By contrast, TNF-α and iNOS contents were upregulated in imidacloprid-exposed Caco-2 cells. Decrease in tight and adherens junctions proteins indicates that the barrier function of intestine epithelial cells could be damaged by imidacloprid administration. In addition, TNF-α and iNOS upregulation indicates that imidacloprid is potent to activate proinflammatory response in enterocytes. Thus, imidacloprid can affect intestine barrier function through the increase of proinflammatory cytokine production and decrease in adhesiveness of enterocytes. The further assessment of the role of adhesion proteins and inflammatory cytokines in neonicotinoid pesticide cytotoxicity as it affects enterocyte barrier function is required to highlight the risk factor of use of neonicotinoids.

The spread of PEDV of pigs continues in various countries and regions of the world. PED was first registered in several areas of Ukraine in 2014. At present, there is a limited number of publications on the characteristics of the spread of the virus infection in Ukraine. Moreover, obtained research data do not clarify the epizootic situation as a whole. Having regard to the state of pig farm industry and permanent growth of losses caused with PEDV infection, the study of PED in Ukraine is relevant and important. Therefore, the goal of the work was to clarify the epizootic situation of PED in various areas of Ukraine. We studied the epizootic state of PED with a typical course in pig farms and the made a primary assessment of the relation of genetic groups between identified pathogens from distinct regions of the country where the highest intensity of the epizootic process was determined. The work was carried out in the Biosafety Center (Ukraine). To determine the epizootic situation of PED during ‎2016–2017 we collected samples of the blood serum and biological materials from pigs from 105 agricultural enterprises that are located in 85 administrative regions of Ukraine. In total we tested 543 serum samples and 591 samples of pathological tissues. The detection of PEDV was performed by PCR-RT. Serological diagnostics were tested with ELISA. Sequence analysis was performed according to Sanger. The results of sequences were analyzed in the FinchTV / Chromas program. The analysis of the epizootic features of PED in different areas of Ukraine for ‎2016–2017 established that PEDV is the main causative agent of the infection. An infection circulates among sensitive animals in pig farms and induces PED, which is difficult to control and weakly managed as a particularly dangerous emergent infectious disease of pigs. In 2016, 6.5% of administrative districts located in 12 of the 25 regions of Ukraine were included in the study, and in 2017, 10.8% of administrative districts located in the 14 regions of the 25 regions of the country were investigated. In general, during 2016 and 2017 1134 samples of blood serum and animal tissue were collected from 105 agricultural enterprises from 17.3% of the administrative regions of Ukraine. The obtained results showed that in 2016 PED was registered in 7 administrative districts from 4 regions of Ukraine, and in 2017 the infection was registered in 2 regions. The results of RNA sequence analysis of the PED virus identified the characteristics of the PEDV genes which reflect a high degree of homology with the Chinese strain BJ-2011-1. The analysis of the obtained results revealled the relation of PEDV circulating in Ukraine to the strains identified in the USA. Moreover, the samples of PEDV from Ukrainian pig farms have the sequences that belong to the North American clade II from the group of 2 strains of the PED virus. However, the PEDV observed in Ukraine is different from them by at least one nucleotide replacement of the gene which codes a protein of the S domain. Based on the obtained results, it can be assumed that in Ukraine the PED virus could have spread from East Asia.

The paper presents the results of a study on the formation of colostral immunity and the determination of its duration during the first months of life of calves according to the indications of the level of total IgG and antigen-specific antibodies to pathogens of рarainfluenza 3, respiratory syncytial infection and viral diarrhea of cattle. It has been established that blood serum of newborn calves does not contain antigen-specific immunoglobulins of class G to pathogens of viral diarrhea, respiratory syncytial infection and parainfluenza-3, and the level of total IgG is 2.2 ± 0.61 g/dm3. The concentration of total IgG is increased to 50.50 ± 6.33 g/dm3, and decreases to 27.25 ± 5.82 g/dm3 for 28 days, which contributes to the formation of the immunosuppressive state at the 7th day of a calf life. Starting from 35th day, there is an increase in the concentration of total IgG due to seroconverting of its own antibodies by the body of calves. Immunization of cows-mothers against viral diarrhea, respiratory syncytial infection and parainfluenza-3 contributes to the formation of antigen-specific colostral immunity in calves in the first days of life, which is preserved in diagnostic titers during 63 days after birth.

The article presents new scientific data on the expression of plasmalemma proteins of the absorptive enterocytes of the bovine intestines of five to nine months of age. In the late fetal period, 31 and 27 protein fractions of apical and basolateral membranes, respectively, were found in the plasmalemma of the jejunum intestine, which had a molecular weight of 9.6 kDa to 300 kDa. Twenty-nine protein fractions were detected in the apical membranes of five-month-old cattle enterocytes. It should be noted that protein fractions with low molecular weight (up to 24 kDa) were only 19.7 %, with molecular weights from 24 kDa to 100 kDa – 69.2 %, and fractions with molecular weights of 100 kDa and more were detected only – 11.1 % of the total number of polypeptides. Twenty-five protein fractions with a molecular weight of 9.6 to 155 kDa were found in the basolateral enterocyte membranes of five-month-old fetus. A large proportion of the detected protein fractions belonged to low molecular weight polypeptides (9.6–24 kDa – 40.26 %). Proteins with a molecular weight of 24–95 kDa – 55.2 %, with a molecular mass of 100 kDa and more were found only 4.56 %. High molecular weight proteins in the basolateral membrane of jejunum enterocytes of five-months-old cattle with a molecular weight greater than 155 kDa were not detected by electrophoresis (unlike the apical membrane). Analysis of the results of studies membranes protein of cattle enterocytes in late fetal period indicates significant changes in their polypeptide composition. In particular, in the basolateral membranes of enterocytes during the late fetal period there is a decrease in the content of low molecular weight protein fractions (3.3 times; P ≤ 0.001) and an increase in the proportion of high molecular weight. In addition, from the age of eight months, proteins with a molecular weight of 9.6–14.2 kDa and 75 kDa disappear in the basolateral membrane. Instead, proteins with a molecular weight of 300 kDa and 170-1885 kDa are appeared. In addition, in the apical membranes of enterocytes there is a significant decrease in the content of low molecular weight protein fractions and an increase in polypeptides with a molecular weight greater than 100 kDa. The appearance in the apical membranes of jejunum enterocytes of calves from eight months of age embryonic development of fractions of polypeptides with molecular weight of 24 kDa and 66 kDa, which are present until the end of the fetal period.

No abstract

In lymph nodes, as peripheral organs of the immune system, the patterns of their growth and development are unique in many ways, especially during the prenatal period of ontogenesis. The changes in the absolute and relative mass of lymph nodes in 66 bovine fetuses of different gestational ages (2–9 months) were studied. The weight of the fetuses and organs was determined with an accuracy of 0.001 g. According to the indicators of weight, body length, and the degree of development of the fetal skin derivatives, their age was established. It was found that in the first third of the fetal period of ontogenesis, the dynamics of the lymph nodes’ absolute mass was characterized by a moderate increase, which occurred simultaneously with an increase in the weight of the fetus itself. The relative weight at the beginning of the fetal period changed unevenly: it decreased in the superficial cervical and mandibular and increased in the popliteal and caudal mediastinal lymph nodes. In the second third of the fetal period, both the absolute and the relative weight of the examined organs increased dramatically (with the maximum at 7 months-old age). During the last third of the fetal period, a gradual increase in the absolute mass of all lymph nodes was found, and their relative mass, on the contrary, decreased moderately. In the second and last third of prenatal development, there was no direct relationship between the growth of the lymph nodes mass and the fetal total mass.