<abstract><title style='display:none'>Abstract</title> The progressive growth and spread of tumour cells in the form of metastases requires an interaction of healthy host cells, such as endothelial cells, fibroblasts, and other cells of mesenchymal origin with immune cells taking part in innate and adaptive responses within the tumour lesion and entire body. The host cells interact with tumour cells to create a dynamic tumour microenvironment, in which healthy cells can both positively and negatively influence the growth and spread of the tumour. The balance of cellular homeostasis and the effect of substances they secrete on the tumour microenvironment determine whether the tumour has a tendency to grow or disappear, and whether the cells remain within the lesion or are capable of metastasis to other regions of the body. Intercellular interactions also determine the tumour’s susceptibility to radiation or other types of cancer treatment. They may also be a rational explanation for differences in treatment outcomes, in which some metastases regress and others progress in response to the same treatment method.</abstract>

Mechanisms of tumour escape from immune surveillance

<abstract><title style='display:none'>Abstract</title> Current knowledge about the function of the reproductive tract and appropriate use of hormonal drugs affords control of the oestrus cycle of cows. One of the hormonal protocols is OvSynch, which enables artificial insemination (AI) to be performed at the precise optimum time without control of the ovaries and uterus. Use of such protocols in reproductive management allows oestrus cycles to be synchronised and cows to be effectively inseminated without oestrous detection, which is time-consuming and difficult in farms with numerous cows. Therefore, OvSynch has become the first management tool for AI and is an alternative method to heat detection. Over the 20 years since its first implementation, OvSynch has been modified many times to improve its reproduction outcomes and widen its use. Besides its original use for heat synchronisation, it is also used in many ovarian disorders as a therapeutic method. This review article describes the possibilities which OvSynch provides, its current modifications, various applications, and the advantages and disadvantages of its use in practice.</abstract>

OvSynch protocol and its modifications in the reproduction management of dairy cattle herds – an update

<abstract><title style='display:none'>Abstract</title> Introduction: The article presents a rapid and simple analytical procedure for determination of four tetracyclines (oxytetracycline, tetracycline, chlortetracycline, and doxycycline) in animal medicated feedingstuffs. Material and Methods: Two-gramme samples were extracted by a Na2EDTA-McIlvaine buffer (pH 4)/methanol mixtures (40/60, v/v). The determination was achieved by liquid chromatography using a Zorbax Eclipse XDB C18 analytical column with mass spectrometer detection (LC-MS). Results: Recoveries of the antibiotics from spiked feed samples ranged from 78.2% to 113.5%. The LOD and LOQ for tetracyclines in feeds ranged from 2.8 to 4.2 and from 4.3 to 5.7 mg/kg, respectively. Conclusion: The method was successfully validated and proved to be efficient, precise, and useful for quantification of tetracyclines in medicated feedingstuffs.</abstract>

Analytical procedure for the determination of tetracyclines in medicated feedingstuffs by liquid chromatography-mass spectrometry

<abstract><title style='display:none'>Abstract</title>Changes occurring in freshwater ecosystems seem to be fundamental in the development of all microorganisms, including those pathogenic to fish. This has been especially evident in recent years during which dynamic variations in bacterial fish pathology have been observed. Gram-negative bacteria commonly known to be pathogenic to fish, like <italic>Aeromonas</italic> spp., <italic>Flavobacterium</italic> spp., <italic>Pseudomonas</italic> spp., and <italic>Shewanella putrefaciens</italic> are replaced by other species, which until now have not been known to be virulent or even conditionally pathogenic to fish. Nowadays, among these other species <italic>Acinetobacter</italic> spp., <italic>Plesiomonas shigelloides</italic>, <italic>Sphingomonas paucimobilis</italic>, and <italic>Stenotrophomonas maltophilia</italic> are the most frequently isolated from fish exhibiting clinical signs of disease. Two Gram-positive bacteria have become pathogens of particular importance in fish pathology in Poland: <italic>Lactococcus garviae</italic> and <italic>Streptococcus iniae</italic>. In addition, infections caused by the Gram-positive bacterium <italic>Kocuria rhizophila</italic> have appeared in recent years. This bacterium has not been known until now to be pathogenic to fish. Therefore, this infection could be called an emergent disease.</abstract>

Contemporary threats of bacterial infections in freshwater fish

<abstract>
<title style='display:none'>Abstract</title>
 A sensitive and reliable method has been developed and validated to determine residues of abamectin, doramectin, eprinomectin, ivermectin, and moxidectin in bovine milk. Isolation of the analytes from milk was performed with the use of liquidliquid extraction with acetonitrile in the presence of sodium chloride. The extract was defatted with hexane and cleaned up using solid phase extraction (C8 cartridge) after forming ion pairs with triethylamine. The analytes were derivatized with N, Ndimethylformamide, acetic acid anhydride, and N-methylimidazole (100°C, 90 min). The derivatives were determined by reverse phase liquid chromatography with fluorescence detection (excitation and emission wavelength 365 nm and 475 nm, respectively). Recoveries of the lactones from milk samples fortified at 10-30 μg kg-1 ranged from 52% to 80% with intra-laboratory reproducibility (CV) of 12.7%-22.8%. The critical concentrations (decision limit, CCα and detection capability, CCβ) were in accordance with target limits. The method has been verified in the proficiency studies by EURL/CVL Berlin (all z-scores in the range of ±2). The method was transferred to routine laboratories, verified in inter-laboratory comparison and successfully applied in the National Residue Control Plan.
</abstract>

Control of Residues of Five Macrocyclic Lactones in Cow Milk By Liquid Chromatography with Fluorescence Detection

<abstract><title style='display:none'>Abstract</title>Coronaviruses (CoVs) are a large group of enveloped viruses with a single-strand RNA genome, which continuously circulate in mammals and birds and pose a threat to livestock, companion animals, and humans. CoVs harboured by avian species are classified to the genera gamma- and deltacoronaviruses. Within the gamma-CoVs the main representative is avian coronavirus, a taxonomic name which includes the highly contagious infectious bronchitis viruses (IBVs) in chickens and similar viruses infecting other domestic birds such as turkeys, guinea fowls, or quails. Additionally, IBVs have been detected in healthy wild birds, demonstrating that they may act as the vector between domestic and free-living birds. Moreover, CoVs other than IBVs, are identified in wild birds, which suggests that wild birds play a key role in the epidemiology of other gammaCoVs and deltaCoVs. Development of molecular techniques has significantly improved knowledge of the prevalence of CoVs in avian species. The methods adopted in monitoring studies of CoVs in different avian species are mainly based on detection of conservative regions within the viral replicase, nucleocapsid genes, and 3’UTR or 5’UTR. The purpose of this review is to summarise recent discoveries in the areas of epidemiology and diagnosis of CoVs in avian species and to understand the role of wild birds in the virus distribution.</abstract>

Coronaviruses in avian species – review with focus on epidemiology and diagnosis in wild birds

<abstract>
<title style='display:none'>Abstract</title>
<sec>
<title style='display:none'>Introduction</title>
Chicken bones, a by-product of the poultry industry, can directly or indirectly enter the food chain. Bone meal and bone products could be sources of many contaminants. Considering the wide range of uses made of bones in the culinary and food industries, this material needs to be safe and antibiotic residue–free. To determine if such is the case, the concentration of doxycycline in chicken bones was investigated, this antimicrobial being one of the most commonly used in poultry production.
</sec>
<sec>
<title style='display:none'>Material and Methods</title>
Ross 308 broilers were grouped into three experimental and one control group. Doxycycline was administered in drinking water at therapeutic and sub-therapeutic doses, as well as <italic>via</italic> spray treatment. The concentration of doxycycline in bones was determined post slaughter by ultra-high performance liquid chromatography–tandem mass spectrometry.
</sec>
<sec>
<title style='display:none'>Results</title>
Doxycycline was quantified at 135 μg/kg 22 days after the last day of antibiotic administration at therapeutic doses; 2,285 μg/kg after sub-therapeutic treatment for 27 days and 9.62 μg/kg 22 days after the end of spray application.
</sec>
<sec>
<title style='display:none'>Conclusion</title>
High concentrations and long persistence of doxycycline in bones were found in this study. Doxycycline can contaminate all bone-derived products in the food and fertiliser industries.
</sec>
</abstract>

Investigation of doxycycline residues in bones after oral administration to broiler chickens

<abstract>
<title style='display:none'>Abstract</title>
<sec>
<title style='display:none'>Introduction</title>
Exosomes are nanosized lipid bilayer membranous microvesicles, extracellularly released from a variety of mammalian cells. They mediate intercellular signalling by transporting several types of RNA, lipids and proteins and participate in the intercellular exchange of DNA, RNA, micro RNA, proteins and other components. These microvesicles are present in all body fluids in physiological and pathological conditions and reflect the state of the host organism. The aim of the study was the isolation and molecular determination of exosomes in blood and supernatant fluids of bovine dendritic cell cultures infected with bovine leukaemia virus (BLV).
</sec>
<sec>
<title style='display:none'>Material and Methods</title>
Exosomes were isolated by ultracentrifugation from the blood sera, plasma and supernatant of bovine BLV-infected and uninfected control dendritic cell cultures and their presence was confirmed with scanning electron and transmission electron microscopy. Western blot analysis of the structural BLV glycoprotein 51 (Env) and protein 24 (Gag) and of the tetraspanin exosomal markers CD9, CD63 and flotillin-1 was undertaken in BLV+ and control BLV− cattle.
</sec>
<sec>
<title style='display:none'>Results</title>
In exosomes of leukaemic cattle both BLV proteins and exosomal markers were detected. In healthy control animals only exosomal markers were determined.
</sec>
<sec>
<title style='display:none'>Conclusion</title>
Proteins of BLV were released with exosomes and could be transferred into recipient cells as an alternative propagation route not requiring virus infection.
</sec>
</abstract>

Extracellular vesicles in cattle infected with bovine leukaemia virus: isolation and molecular analysis

<abstract>
<title style='display:none'>Abstract</title>
<sec>
<title style='display:none'>Introduction</title>
No maximum residue limits in honey have been legislated in the EU for antimicrobial substances such as sulphonamides, and they are not permitted, therefore, for treating honey bees unless in a cascade system. Since sulphonamides are used illegally in apiculture to treat foulbrood, their residues can be found in honey and other apiculture products, including beeswax. The study aimed to assess the contamination of honey from beeswax containing residues of 10 sulphonamides (sulphadimethoxine (SDM), sulphadoxine (SDX), sulphamonomethoxine (SMM), sulphamethoxazole (SMX), sulphameter (SMT), sulphamethazine (SMZ), sulphamerazine (SMR), sulphadiazine (SDA), sulphathiazole (STZ) and sulphacetamide (SCA)).
</sec>
<sec>
<title style='display:none'>Material and Methods</title>
Wax-based foundations fortified with 10 sulphonamides at 10,000 μg/kg were evaluated for sulphonamide concentrations and then placed in a beehive so that honey bees (<italic>Apis mellifera</italic> L.) could build honeycombs with them. Frames of capped honey were taken out of the hives one month later and honey was sampled from them. The honeycombs were subsequently incubated in a laboratory at 35°C for five months, and honey was sampled monthly. The honey sulphonamide concentrations were measured using liquid chromatography–tandem mass spectrometry and compared to the wax-based foundation concentrations.
</sec>
<sec>
<title style='display:none'>Results</title>
The maximum transfers to honey of the initial amount of SDM, SDX, SMM, SMX, SMT, SMZ, SMR, SDA, STZ and SCA in the wax-based foundations were 42.6, 34.3, 31.7, 30.1, 29.5, 25.2, 18.7, 16.1, 9.5 and 8.6%, respectively.
</sec>
<sec>
<title style='display:none'>Conclusion</title>
This study demonstrated that every tested sulphonamide could migrate from beeswax in antimicrobial-tainted honeycombs to honey, SDM having the highest migration potential and SCA the lowest.
</sec>
</abstract>

Comparison of transfer of different sulphonamides from contaminated beeswax to honey

<abstract>
<title style='display:none'>Abstract</title>
<sec>
<title style='display:none'>Introduction</title>
The productivity of domestic animals and the safety of food products derived from them are jeopardised by mycotoxins in animal feed. To control them, feed additives are used, which limit the absorption of mycotoxins in the gastrointestinal tract of animals by binding to them. The study aimed to evaluate the effectiveness of a new <italic>in vitro</italic> model in experiments on the binding of mycotoxins from buffers and contaminated feed and to confirm the effect of a single sorbent or mixture in binding them.
</sec>
<sec>
<title style='display:none'>Material and Methods</title>
Nine mineral sorbents were tested for their efficiency binding eight mycotoxins. Two <italic>in vitro</italic> experiments were conducted to indicate the mycotoxin-binding capacity of sorbents, each specifying a buffer with one of two different pH levels reflecting gastrointestinal conditions (pH 3.5 and 7.0). The first investigated the sorbent with only the buffer and mycotoxin standards, while the second did so with the sorbent, buffer and feed naturally contaminated with mycotoxins (deoxynivalenol, zearalenone, and ochratoxin A).
</sec>
<sec>
<title style='display:none'>Results</title>
The sorption was significantly lower in the trial with feed. In the first experiment at gastric pH (pH 3.5), activated charcoal bound deoxynivalenol and sepiolite bound zearalenone at 70% and 96%, respectively, whereas in the second experiment with feed, the binding was only 3% and 6%.
</sec>
<sec>
<title style='display:none'>Conclusion</title>
The study underlines the challenge of finding a feed additive that would work comprehensively, binding all mycotoxins regulated by law.
</sec>
</abstract>

The efficiency of mycotoxin binding by sorbents in the <italic>in vitro</italic> model using a naturally contaminated animal feed

<abstract>
<title style='display:none'>Abstract</title>
<sec>
<title style='display:none'>Introduction</title>
Outbreaks of fowl adenovirus (FAdV) infection in chicken flocks in Poland threaten birds’ health and lives and are rising in frequency. The risk of these infections in immunocompromised poultry flocks with developed clinical symptoms was analysed through virus detection in broiler chicks and correlation of cases with the birds’ immune strength.
</sec>
<sec>
<title style='display:none'>Material and Methods</title>
Samples were analysed from four broiler farms with chicks from the same hatchery in Silesia, Poland where feeding regimes were different. A normal diet was provided to birds on the control farm; a normal diet and probiotic, prebiotic, vitamin and microelement supplementation was supplied on another farm; a normal diet and antibiotics on the third; and a normal diet and both forms of supplementation were given on the fourth farm. Amplification of the virus DNA in a PCR with hexon gene L1 loop hypervariable region 1–4 primers determined the molecular characteristics of isolates of adenovirus strains obtained from necropsy tissue samples. The amplicon sequences were analysed, the pair-wise distances were determined, the maximum likelihood estimate for the gamma parameter for site rates was produced, Tajima’s D neutrality test was run and the relative synonymous codon usage and transition/transversion bias were calculated.
</sec>
<sec>
<title style='display:none'>Results</title>
Two species and two serotypes of fowl adenovirus – MW353018-FAdV-1/A-L-liver and MW353019-FAdV-5/B-I-intestine – were isolated in three-week-old broiler chicks on the control farm.
</sec>
<sec>
<title style='display:none'>Conclusion</title>
Supplementation of broiler chicken flocks with probiotics, prebiotics, vitamins and microelements may have a significant beneficial effect on immunity and can prevent virus infection. The studies provided new information on the molecular characteristics of adenovirus strains isolated from chicks with a low level of immunity.
</sec>
</abstract>

Molecular characteristics of fowl adenovirus strains detected in broiler chickens on diets without immunostimulant supplements

<abstract>
<title style='display:none'>Abstract</title>
<sec>
<title style='display:none'>Introduction</title>
The objective of the research was to investigate the effect of <italic>Saccharomyces cerevisiae</italic> supplementation on some acute-phase proteins, haptoglobin and all electrophoretic parameters in young Charolaise bulls.
</sec>
<sec>
<title style='display:none'>Material and Methods</title>
Sixty bulls were divided into two equal groups: the control group (CG) receiving the base diet without yeast supplementation and the diet supplementation group (YG) receiving the base diet with 5g of <italic>Saccharomyces cerevisiae</italic> supplementation. The base diet was total mixed ration allocated at 11.85 kg per animal per day. Blood samples were collected from all bulls on day 0 before the start of the diet supplementation, and on days 20 and 40 after the start. Total proteins, albumin, globulin fraction (α1-, α2-, β1-, β2- and γ-globulins), albumin: globulin ratio (A: G) and haptoglobin were determined.
</sec>
<sec>
<title style='display:none'>Results</title>
Two-way analysis of variance showed a significant effect of the yeast feeding time on all studied parameters except α2-globulins in both groups. The YG showed a higher average concentration of total proteins, albumin and A: G and a lower average concentration of γ-globulins and haptoglobin than the CG.
</sec>
<sec>
<title style='display:none'>Conclusion</title>
These results indicated the beneficial effect of the <italic>Saccharomyces cerevisiae</italic> on the inflammatory status of the young bulls, which showed an adequate response in serum levels of the acute-phase proteins tested.
</sec>
</abstract>

Diet supplementation with <italic>Saccharomyces cerevisiae</italic> influences the electrophoretic parameters in blood in young Charolaise bulls

<abstract>
<title style='display:none'>Abstract</title>
Since 2007, African swine fever (ASF) has posed a serious threat to the European swine industry. In Poland, the numbers of reported outbreaks in pigs and affected areas grow every year. In 2018, the disease was noted in Western Europe, in Belgium specifically, where several hundred infected wild boars have been detected so far. In 2018, the virus unexpectedly emerged in pig holdings in eastern China, northern Mongolia, Vietnam, and Cambodia, causing worldwide concern about its further spread. Since there is still no vaccine available, the only approach to control the disease is biosecurity. Identification of potential sources of the virus is extremely important in light of its phenomenal survivability. The review summarises the current knowledge about ASFV survivability and resistance to environmental conditions, and discusses the role of indirect contact in spreading the disease.
</abstract>

African swine fever virus – persistence in different environmental conditions and the possibility of its indirect transmission

<abstract><title style='display:none'>Abstract</title>African swine fever virus (ASFV) is a large, double-stranded DNA virus and the sole member of the <italic>Asfarviridae</italic> family. ASFV infects domestic pigs, wild boars, warthogs, and bush pigs, as well as soft ticks (<italic>Ornithodoros erraticus</italic>), which likely act as a vector. The major target is swine monocyte-macrophage cells. The virus can cause high fever, haemorrhagic lesions, cyanosis, anorexia, and even fatalities in domestic pigs. Currently, there is no vaccine and effective disease control strategies against its spread are culling infected pigs and maintaining high biosecurity standards. African swine fever (ASF) spread to Europe from Africa in the middle of the 20th century, and later also to South America and the Caribbean. Since then, ASF has spread more widely and thus is still a great challenge for swine breeding. The genome of ASFV ranges in length from about 170 to 193 kbp depending on the isolate and contains between 150 and 167 open reading frames (ORFs). The ASFV genome encodes 150 to 200 proteins, around 50 of them structural. The roles of virus structural proteins in viral infection have been described. These proteins, such as pp220, pp62, p72, p54, p30, and CD2v, serve as the major component of virus particles and have roles in attachment, entry, and replication. All studies on ASFV proteins lay a good foundation upon which to clarify the infection mechanism and develop vaccines and diagnosis methods. In this paper, the roles of ASFV structural proteins in viral infection are reviewed.</abstract>

Roles of African swine fever virus structural proteins in viral infection

<abstract>
<title style='display:none'>Abstract</title>
In 2015 in the European Union member states listeriosis caused 270 deaths. Food is the route of transmission in 99% of all human infection cases. Several studies from different countries have shown that the presence of <italic>Listeria monocytogenes</italic> in food can be as high as 58.3%. One of the most important ways to protect food from these microorganisms is to prevent the spread of the bacteria at processing plants at different stages of food production chain. The ability of <italic>L</italic>. <italic>monocytogenes</italic> to survive in extreme conditions and to form biofilms on various surfaces is a significant challenge for food safety. Removal of these bacteria from niches in processing plants is difficult and requires the use of sanitisers and precise equipment cleaning. The presence of <italic>L</italic>. <italic>monocytogenes</italic> in processing environment at slaughterhouses, deli meat factories or in retail may be a reason of cross-contamination. Proper hygienic systems applied by workers in food preparing places and knowledge about different routes of spreading of these bacteria may effectively decrease the risk of food contamination. Standardised legal regulations and control of meat product manufacture should be a fundamental way to protect food from <italic>L</italic>. <italic>monocytogenes</italic> contamination.
</abstract>

Ready-to-eat meat products as a source of <italic>Listeria monocytogenes</italic>

<abstract><title style='display:none'>Abstract</title>The aim of this paper is to give an overview of the presence of biogenic amines, particularly histamine, in various food products, discuss the most important factors influencing their accumulation, and address potential toxicity and safe limits in food. Biogenic amines are natural components of animal and plant raw materials, where they are present at concentrations appearing non-harmful to human health. Their increased content in foods results from the activity of endogenous enzymes or from the microbial decarboxylation of amino acids during controlled or spontaneous fermentation, processing, storage, and distribution. General knowledge of biogenic amines, factors favouring their formation and their safe limits in food are useful in preventing exposure to their toxic effects on the human body. Based on this information, appropriate prophylaxis can be applied, which will consist primarily of maintenance of good hygiene standards of raw materials and products, employment of appropriate processing procedures and upkeep of sanitary food storage conditions.</abstract>

Histamine and other biogenic amines in food

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