Polystyrene microparticles can affect the health status of freshwater fish - Threat of oral microplastics intake

Plastic waste pollution is considered one of the biggest problems facing our planet. The production and use of these materials has led to huge amounts of plastic waste entering the aquatic environment and affecting aquatic life. In our experiment, the effect of polystyrene microparticles (PS-MPs; 52.5 ± 11.5 μm) on individual juvenile rainbow trout (Oncorhynchus mykiss) was tested at three different dietary concentrations of 0.5, 2 and 5 % for six weeks. At the end of the experiment, various health parameters of exposed organisms were compared with the control group. The haematological profile revealed an immune response by a decrease in lymphocyte count with a concurrent increase in the number of neutrophil segments at the highest concentration of PS-MPs (5 %). Biochemical analysis showed significant reductions in plasma ammonia in all tested groups, which may be related to liver and gill damage, as determined by histopathological examination and analysis of inflammatory cytokines expression. In addition, liver damage can also cause a significant decrease in the plasma protein ceruloplasmin, which is synthesized in the liver. PS-MPs disrupted the antioxidant balance in the caudal kidney, gill and liver, with significant changes observed only at the highest concentration. In summary, PS-MPs negatively affect the health status of freshwater fish and represent a huge burden on aquatic ecosystems.

Non-steroidal anti-inflammatory drugs caused an outbreak of inflammation and oxidative stress with changes in the gut microbiota in rainbow trout (Oncorhynchus mykiss)

One of the main contributors to pharmaceutical pollution of surface waters are non-steroidal anti-inflammatory drugs (NSAIDs) that contaminate the food chain and affect non-target water species. As there are not many studies focusing on toxic effects of NSAIDs on freshwater fish species and specially effects after dietary exposure, we selected rainbow trout (Oncorhynchus mykiss) as the ideal model to examine the impact of two NSAIDs - diclofenac (DCF) and ibuprofen (IBP). The aim of our study was to test toxicity of environmentally relevant concentrations of these drugs together with exposure doses of 100× higher, including their mixture; and to deepen knowledge about the mechanism of toxicity of these drugs. This study revealed kidneys as the most affected organ with hyalinosis, an increase in oxidative stress markers, and changes in gene expression of heat shock protein 70 to be signs of renal toxicity. Furthermore, hepatotoxicity was confirmed by histopathological analysis (i.e. dystrophy, congestion, and inflammatory cell increase), change in biochemical markers, increase in heat shock protein 70 mRNA, and by oxidative stress analysis. The gills were locally deformed and showed signs of inflammatory processes and necrotic areas. Given the increase in oxidative stress markers and heat shock protein 70 mRNA, severe impairment of oxygen transport may be one of the toxic pathways of NSAIDs. Regarding the microbiota, an overgrowth of Gram-positive species was detected; in particular, significant dysbiosis in the Fusobacteria/Firmicutes ratio was observed. In conclusion, the changes observed after dietary exposure to NSAIDs can influence the organism homeostasis, induce ROS production, potentiate inflammations, and cause gut dysbiosis. Even the environmentally relevant concentration of NSAIDs pose a risk to the aquatic ecosystem as it changed O. mykiss health parameters and we assume that the toxicity of NSAIDs manifests itself at the level of mitochondria and proteins.

Effects of plastic particles on aquatic invertebrates and fish - A review

This review summarises the current knowledge on the effects of microplastics and their additives on organisms living in the aquatic environment, particularly invertebrates and fish. To date, microplastics have been recognised to affect not only the behaviour of aquatic animals but also their proper development, causing variations in fertility, oxidative stress, inflammations and immunotoxicity, neurotoxicity, and changes in metabolic pathways and gene expression. The ability of microplastics to bind other xenobiotics and cause combined toxicity along side the effect of other agents is also discussed as well. Microplastics are highly recalcitrant materials in both freshwater and marine environments and should be considered extremely toxic to aquatic ecosystems. They are severely problematic from ecological, economic and toxicological standpoints.

Do foodborne polyethylene microparticles affect the health of rainbow trout (Oncorhynchus mykiss)?

Due to the fact that plastic pollution is a global environmental problem of modern age, studies on the impact of these synthetic materials on aquatic, and especially fish organisms, are an important part of the ecosystem and human nutrition. In our study, the toxicity of pristine polyethylene (PE) microparticles (approx. 50 μm) on rainbow trout (Oncorhynchus mykiss) was tested in three different dietary concentrations - 0.5%, 2% and 5%. After six weeks of exposure, various health indices were evaluated. Electron microscopy of the intestine revealed the disintegration of PE particles to <5 μm in size, and thus we concluded that microplastics are able to reach tissues. The haematological profile revealed changes in total red blood cells count and haematocrit (5% PE) which could be associated with spleen congestion observed histologically. The marker of lipid peroxidation was increased in gills suggesting the disruption of balance in antioxidant enzymes capacity and histopathological imaging revealed inflammation in higher PE concentrations. In addition, ammonia was decreased and calcium elevated in biochemical profile, confirming the gill damage. Electron microscopy of the gills showed lesions of lamellae and visible rings around the mucinous cell opening indicating their higher activity. Another injured was the liver tissue, as confirmed by hepatodystrophies and increased expression of pro-inflammatory genes in 2% PE. Impaired innate immunity was confirmed by an increased presence of mucinous cells and a decrease in leukocytes. Kidney damage manifested itself by higher expression of pro-inflammatory cytokines and histopathology. The damage in gills, liver and kidney together correlated with the increased antioxidant capacity of plasma. In conclusion, PE microparticles are able to affect health indices of O. mykiss. The potential problem for aquatic ecosystems and even human consumption should be considered.

Platelet-rich plasma, platelet-rich fibrin, and enamel matrix derivative for oral mucosal wound healing

Different approaches to enhance healing of hard or soft tissues include the use of cytokines and growth factors to modify cellular behaviour. Numerous growth factors are found in autologous blood concentrates - platelet-rich plasma (PRP) and platelet-rich fibrin (PRF). Enamel matrix derivative (EMD) may improve tissue healing via amelogenins. Bilayered collagen matrix (CM) is used for soft tissue augmentation. The aim of the present study was to assess potential benefits of PRP, PRF and EMD in combination with bilayered collagen matrix or CM alone in treatment of oral mucosal defects in rabbits. Twenty-seven New Zealand white rabbits were included in this randomized controlled trial. Artificial oral mucosal defects were treated with one of these five approaches: PRP+CM, PRF+CM, EMD+CM, CM alone, or left untreated as a negative control - CO. The animals were euthanized 1 day, 7 days, or 28 days after surgery and necropsies were harvested. Histological and molecular biological analyses were performed. All defects were healed by day 28. No differences between PRP+CM, PRF+CM, CM alone and CO groups were recorded at any time point. Slower angiogenesis and a higher presence of inflammatory infiltrate were observed in the EMD+CM group 28 days after surgery. Molecular biological analyses did not reveal any statistically significant changes. In conclusion, no improvement in mucosal healing of wounds covered with a collagen membrane and PRP, PRF, or EMD was observed, compared with CM alone or untreated controls.

Detection of IgM-rheumatoid factor and anti-citrullinated protein antibodies in healthy horses and their comparison

Rheumatoid factor (RF) is used in human and veterinary medicine in the form of IgM RF traditionally to support the diagnosis of rheumatoid arthritis (RA). In the latest diagnostic criteria, presence of anti - citrullinated protein antibodies (ACPA) was added to the grading system for the diagnosis of RA in humans. A change which is not integrated or routinely used in veterinary medicine. The criteria changed partly because of RF's diagnostic shortcomings, which include its increased titer detection in humans with non-rheumatoid diseases, inability to predict the disease and increased titers over the limit in the older population. Clinical signs similar to human RA were reported in horses in a condition known as idiopathic polysynovitis. Similarities in the clinical presentation to RA raised a question to the usability of RF and ACPA in horses. In our study, sixty clinically healthy horses, ranging from 3 days to 30 years of age, were evaluated for their serum levels of IgM RF. 55 of these horses were tested for ACPA, using methods of ELISA measuring Anti - CFG (Anti citrullinated fibrinogen antibody). The results of the study demonstrated the existence of an age-dependent increase in the level of IgM RF up to the age of about 9 years and ACPA's independence of the horse's age as well as both markers independence of the horse sex.

The effects of live yeast Saccharomyces cerevisiae on postweaning diarrhea, immune response, and growth performance in weaned piglets

The effects of live yeast Saccharomyces cerevisiae (strain CNCM I-4407, 10(10) cfu/g; Actisaf; Lesaffre Feed Additives, Marcq-en-Baroeul, France) on the severity of diarrhea, immune response, and growth performance in weaned piglets orally challenged with enterotoxigenic Escherichia coli (ETEC) strain O149:K88 were investigated. Live yeast was fed to sows and their piglets in the late gestation, suckling, and postweaning periods. Sows were fed a basal diet without (Control; n = 2) or with (Supplemented; n = 2) 1 g/kg of live yeast from d 94 of gestation and during lactation until weaning of the piglets (d 28). Suckling piglets of the supplemented sows were orally treated with 1 g of live yeast in porridge carrier 3 times a week until weaning. Weaned piglets were fed a basal starter diet without (Control; n = 19) or with (Supplemented; n = 15) 5 g of live yeast/kg feed for 2 wk. Significantly lower daily diarrhea scores (P < 0.05), duration of diarrhea (P < 0.01), and shedding of pathogenic ETEC bacteria (P < 0.05) in feces was detected in the supplemented piglets. Administration of live yeast significantly increased (P < 0.05) IgA levels in the serum of piglets. Evidence indicates that decreased infection-related stress and severity of diarrhea in yeast-fed weaned piglets positively affected their growth capacity in the postweaning period (P < 0.05). The results suggest that dietary supplementation with live yeast S. cerevisiae to sows and piglets in the late gestation, suckling, and postweaning periods can be useful in the reduction of the duration and severity of postweaning diarrhea caused by ETEC.

γδ T lymphocytes are recruited into the inflamed uterus of bitches suffering from pyometra

Very little is known about the occurrence of immune system cells in the canine uterus. The aim of this study was to generate information about lymphocyte subsets that are present in the healthy canine uterus and that are recruited under inflammatory conditions caused by pyometra. Using immunohistochemistry and flow cytometry, a significant influx of γδ T lymphocytes was found in pyometra samples mainly due to recruitment of γδ(+)/CD8(-) T lymphocytes. The relative expression of genes encoding selected cytokines/chemokines was evaluated in samples from healthy and pyometra-affected uteri. Expression of pro-inflammatory cytokines (including IL-1β, TNF-α, IL-8, IL-17 and IFN-γ) and chemokines (including CXCL10, CCL4 and CCL5) was upregulated in pyometra samples confirming the presence of inflammation. In contrast, the expression of the homeostatic chemokine CCL25 and of the anti-inflammatory cytokine IL-10 was downregulated and unchanged, respectively.

Characterization of CD34⁺ thymocytes in newborn dogs

Using two-color flow cytometry, we characterized CD34(+) cells in the newborn canine thymus. CD34(+) thymic cells comprised approximately 5% of cells recovered by thymus tissue teasing and both large and small thymocytes have been present in this population, the former being 7-12 times more frequent. All CD34(+) cells expressed the pan-leukocyte antigen CD45. The expression of CD44 profile on the large and small CD34(+) thymocytes differed: almost all large CD34(+) cells were CD44(+), while only 75% of small CD34(+) thymocytes co-expressed the CD44 antigen. We have previously described that CD172α is present on the surface of CD34(+) bone marrow cells in dogs. In the thymus, CD172α was expressed on 5-10% and less than 5% of large and small CD34(+) cells, respectively. Some CD34(+) thymocytes also co-expressed T-lineage-specific markers like CD3, CD4, CD8, TCR1 and TCR2. Their expression increased during the large-to-small thymocyte transition. Based on our findings we suggest that thymocyte progenitors enter their primary differentiation center as large CD34(+), CD44(+), CD45(+) and CD172α(+) cells. T-cell specific markers appear on their surface at early stages of differentiation. As the size of progenitors decreases with terminal primary differentiation, the CD34, CD44, and CD172α surface markers are down-regulated.

Salmonella enterica serovar Typhimurium and Enteritidis infection of pigs and cytokine signalling in palatine tonsils

Pigs are considered as one of the major sources of zoonotic strains of Salmonella enterica for humans. Out of many S. enterica serovars, S. Typhimurium dominates in pigs, however, in several countries in Central Europe, S. Enteritidis is also quite frequent in pig herds. In this study we therefore compared the colonisation of pigs with S. Typhimurium and S. Enteritidis. We found that 3 weeks after infection S. Enteritidis 147 colonised the intestinal tract in higher quantities but was shed in faeces in lower quantities than S. Typhimurium 17C10. In a second experiment we found out that S. Enteritidis 147 and its SPI-1 and SPI-4 mutants increased proinflammatory cytokine (IL-1β and IL-8) signalling in the ileum 5 days post infection. On the other hand, independent of SPI-1 or SPI-4, S. Enteritidis 147 suppressed expression of IL-18, MCP1, TLR2, CD86, IL-7, IL-10 and IL-15 in the palatine tonsils. The suppression of cytokine signalling may facilitate the initial colonisation of the palatine tonsils by Salmonella. Moreover, immune suppression may also influence pig resistance to opportunistic pathogens and Salmonella infection in pigs thus may become an issue not only in terms of pork contamination but also in terms of affecting the immunological status of pig herds.

Lactoferrin in canine sera: a pyometra study

The concentration of lactoferrin was measured in canine sera from groups of healthy male dogs as well as pregnant and non-pregnant female dogs and was compared with that of bitches with pyometra. Lactoferrin concentrations were higher in bitches with pyometra. The role of elevated lactoferrin concentrations in the suppression of lymphocyte activity was examined in sera from bitches with pyometra in a series of investigations. Although the sera from bitches with pyometra were capable of suppressing lymphocyte activity, lactoferrin was not found to be involved in this action.

Ontogeny of reactive nitrogen species production by blood phagocytes in pigs

The aim of this work was to evaluate ontogeny of reactive nitrogen species (RNS) production by peripheral blood phagocytes in pig. Pig fetuses (55 and 92 days of gestation) and postnatal piglets (1, 3, 8, 17, 31 and 41 days after birth) were used. RNS production was measured by fluorescent probes diaminofluorescein-diacetate (DAF-FMDA) and dichlorofluorescein-diacetate (H2DCFDA). Levels of nitration of cell proteins were established by immunofluorescent detection of nitrotyrosine. Levels of plasma nitrites/nitrates were detected spectrophotometrically by Griess reaction. Nitric oxide production measured by DAF-FMDA in neutrophils decreased during postnatal life. Spontaneous RNS measured by H2DCFDA decreased from 55th day of gestation to the 41st day of life. Phorbol-12-myristate-13-acetate activated production decreased during postnatal life. Production of NO measured by DAF-FMDA in macrophages decreased from the 1st to 41st day after birth. RNS production measured by H2DCFDA in monocytes did not show any significant changes during ontogeny. The level of nitrotyrosine significantly decreased from the 3rd to 17th day. Levels of plasma nitrites/nitrates gradually decreased from the 55th day of gestation to the 41st day after birth. A temporary increase in all parameters occurred after weaning, but without any significance. In conclusion, RNS production has a decreasing trend during ontogeny and is transiently upregulated after weaning.

Cytokine response of porcine cell lines to Salmonella enterica serovar typhimurium and its hilA and ssrA mutants

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a facultative intracellular bacterium which can infect and colonize pigs. After contact with enterocytes and macrophages, S. Typhimurium induces production of cytokines thus triggering the innate immune response. In this study we evaluated the cytokine response of two porcine cell lines, IPI-2I and 3D4/31, of epithelial or macrophage origins, respectively, to the wild-type S. Typhimurium and its hilA and ssrA mutants. We observed that the 3D4/31 cell line essentially did not respond to S. Typhimurium infection when a medium with foetal calf serum was used. However when the 3D4 cell line was incubated overnight in the presence of porcine serum, it efficiently responded to the wild-type strain and the ssrA mutant but not to the noninvasive hilA mutant as measured by mRNA quantification of TNF-alpha, IL-8 and GM-CSF by the real-time RT-PCR. In IPI-2I, all the cytokines were also induced by the wild-type S. Typhimurium and the ssrA mutant although the induction of TNF-alpha was lower than that induced by the wild-type strain. The hilA mutant was unable to induce any of the cytokines tested. The ssrA mutant can therefore be considered as more suitable for further vaccine development as the stimulation of innate immune response is important for animal protection against a challenge with virulent strains.

Hysterectomy leads to fast improvement of haematological and immunological parameters in bitches with pyometra

OBJECTIVES

To investigate whether a combination of hysterectomy and antibiotic treatment leads to an improvement of altered haematological and immunological parameters in bitches affected by pyometra.

METHODS

Blood samples obtained from 13 bitches affected by pyometra were investigated before hysterectomy and seven days later for a total and differential leucocyte count, activity of neutrophils and lymphocytes, and quantification of total serum immunoglobulins, lysozyme and circulating immune complexes.

RESULTS

The parameters most affected included changes in blood profile (leucocytosis because of neutrophilia or leucopenia) and inhibition of lymphocyte activity. Seven days after hysterectomy, all affected parameters returned to normal levels comparable to clinically healthy dogs.

CLINICAL SIGNIFICANCE

Application of immunostimulating therapy is not necessary to manage changes in blood cell counts and suppression of lymphocyte activity in bitches with pyometra. Removal of the infected uterus, being the source of infection, leads to improvement.

Commercially available rabbit anti-human polyclonal antisera as a useful tool for immune system studies in veterinary species

We have used selected rabbit anti-human polyclonal antibodies as an example of useful and easily available tools for studies on immune system structure and development in important veterinary species, many of which also represent animal models in biomedicine. The cocktail of anti-human Igkappa-FITC/anti-Iglambda-RPE F(ab')(2) fragments was used for two-colour and, in combination with the cross-reactive anti-CD79alpha monoclonal antibody HM-57, for three-colour flow cytometry of canine, feline, bovine and porcine peripheral B-cells. A possible application of such immunoreagents in studies on primary B-cell differentiation has been suggested in pigs; the same approach can be used in other species of interest. Rabbit anti-human lactoferrin-FITC F(ab')(2) fragment was used for visualizing neutrophils in dogs, pigs and cattle and an application for two-colour immunophenotyping of canine granulocyte subsets has been designed. Affinity isolated rabbit anti-human CD3 and anti-human TdT have been shown to represent a ready-to-use tool for in situ studies on primary T-lymphopoiesis in pigs with possible extensions both to the B-lineage development in pigs and other animal models. Altogether, our study show that carefully selected polyclonal antibodies available on the market may possess broad cross-reactivity with important applications in veterinary research.

Cross-reactive anti-human monoclonal antibodies as a tool for B-cell identification in dogs and pigs

We have characterized a panel of commercially available anti-human monoclonal antibodies (mAbs) suitable for B-cell identification in pigs and dogs. The specificities of the mAbs were against CD20, CD21, CD22, and CD86. In addition to HM57, originally raised against human CD79alpha the broad cross-reactivity of which was documented more than 10 years ago, we recommend here a panel of several other mAbs as a useful tool for immunophenotyping and multicolor flow cytometry of canine and porcine B-lymphocytes. All six investigated antibodies did bind weakly to either canine or porcine lymphocytes (or both), but considerable weaker than for the human control cells. Four of them did bind to canine or porcine spleen section in immunohistochemistry. Monoclonal antibody against CD22 (clone RFB-4) was the only antibody in the tested panel the cross-reactivity of which was confirmed by Western blot. The advantages and limits of cross-reactive mAbs in studies on animal B-cells are discussed.

Severe combined immunodeficiency in a Fell pony foal

Five days after birth of a viable Fell pony filly, yellow watery diarrhoea appeared without any signs of systemic disease. Four days later the diarrhoea ceased. On 11th day, the animal showed apathy, and a few days later, the foal was very lethargic, suffered from muscular weakness and severe watery diarrhoea that reappeared. The illness did not respond to therapy. At the age of 21 days the filly spontaneously died under symptoms of intestinal colic and pneumonia. Haematological examinations revealed lower numbers of erythrocytes as well as non-selective lymphopenia. Phagocytic activity was slightly increased, lymphocyte activity was inhibited. Histopathology showed severe alteration of the lymphatic organs. T and B lymphocytes and antigen-presenting macrophages were not arranged in characteristic areas, and the quantity of these cells was lower than would be expected. Histopathological changes in lymphatic organs resembled those described in the literature as severe combined immunodeficiency.

Experimental Actinobacillus pleuropneumoniae infection in piglets with different types and levels of specific protection: Immunophenotypic analysis of lymphocyte subsets in the circulation and respiratory mucosal lymphoid tissue

Actinobacillus pleuropneumoniae (APP) infection in piglets results in severe and fatal fibrinous hemorrhagic necrotizing pneumoniae. The aim of our study was to analyze changes in lymphocyte subset distribution in peripheral blood, bronchoalveolar lavage fluid (BALF) and tracheobronchal lymph nodes (TLN) in non-immune piglets upon a challenge with a high dose of APP and to compare the quality of such changes in unprotected piglets with counterparts exhibiting specific immunity mediated by high titers of colostrum-derived APP-specific antibodies and/or a low dose APP infection in the early postnatal period. Challenge with APP resulted in a massive increase in CD8-negative gammadelta T-cells in parallel with a reduction in numbers of CD3-CD8low cells in BALF independent of the type and level of immunity and this seems to be a general phenomenon associated with experimental infection. An increase in B-lymphocyte numbers in TLN was another characteristic feature accompanying APP infection in all experimental groups. In piglets with colostrum-derived APP-specific antibodies, this was associated with higher relative numbers of IgM+CD2+ lymphocytes in TLN, while B-cells with the CD2- surface phenotype apparently expanded in the absence of passive humoral immunity.

Systemic and Local Antibody Responses after Experimental Infection with Actinobacillus pleuropneumoniae in Piglets with Passive or Active Immunity

The objectives of the present study was to describe different dynamics of humoral immune responses to experimental infection in piglets of different stages of infection and immunity. Two groups of piglets originating from non-immune (group 1) and immune (group 2) sows at the age of 3 weeks were subdivided as follows: a half of each group of piglets was exposed to a low-dose infection with Actinobacillus pleuropneumoniae (APP) strain 9. At the age of 8 weeks, all four groups of piglets were challenged with a high infection dose of APP of the same strain. Isotype characterization of the specific antibodies in sera and in bronchoalveolar lavage fluids (BALF) to a lipopolysaccharide was carried out, besides monitoring clinical signs and post-mortem examinations. A typical primary immune response was observed in specific antibody-free piglets infected with a challenge infection. Colostrum-derived immunoglobulin-G (IgG) antibodies persisted in sera and BALF of piglets up to the age of 8 weeks. However, they did not prevent induction of specific-primary antibody response, either in 8 or 4 weeks of age, when levels of specific colostrum-derived antibodies were still high. It was demonstrated by the increase of specific IgM antibodies in sera. The infection induced an increase in the levels of IgA antibodies in BALF regardless the severity of infection and presence of specific colostrum-derived antibodies. The specific antibodies of IgG isotype increased only in BALF from piglets without colostrum-derived antibodies.

Lymphatic organ development in dogs: major lymphocyte subsets and activity

In the present study, we have characterized lymphocyte subsets and activity in peripheral blood, spleen, mesenteric and popliteal lymph nodes in pups from birth till the age of one month and compared the results with the situation in the group of three adult dogs. In neonatal pups, lower numbers of CD3(+) T-cells were detected in both the spleen and peripheral blood than in lymph nodes. In contrast to the other compartments, CD21(+) B-cells prevailed in the spleen, which resulted in low values (<1) of the CD3(+)/CD21(+) ratio. Low numbers of CD8(+) lymphocytes were characteristic in all compartments immediately after birth; consequently a high CD4(+)/CD8(+) ratio has been calculated. Postnatal development was characterized by an increasing frequency of CD8(+) lymphocytes in all organs studied. Another typical feature of the early period of life was a relative decrease of B-cell numbers, which was compensated by an increasing proportion of T-lymphocytes, particularly in the peripheral blood and spleen. DNA synthesis in newborn pups' cells as measured by in vitro thymidine incorporation was surprisingly high in non-stimulated control samples, notably in the spleen. Further development of lymphocyte activity was characterized by the decline in spontaneous activity in all organs. Stimulation indices upon mitogen-induced proliferation increased proportionally to the decrease in spontaneous activity. Based on our experimental data, we have concluded that pups are born with a relatively competent immune system the structure of which, however, markedly develops during a few postnatal weeks.

Effects of certain inducers of leukocytes migration into the bovine mammary gland on neutrophil apoptosis manifestation in a subsequent in vitro cultivation

The aim of the study was to elucidate the effects of induced leukocyte migration into the bovine mammary gland on the manifestations of early and late apoptotic features of neutrophils cultivated in vitro. The Latin square design was used in two experiments, each involving four experimental repetitions in 4 clinically healthy virgin heifers. The neutrophil early apoptotic features were detected by flow cytometric detection (FCM) of phosphatidyl-serine translocation. Late neutrophil apoptotic features were detected by ELISA quantitation of histone-complexed DNA fragments. Leukocyte influx induction was accomplished by using four inducers: i) sterile buffered saline solution (PBS); ii) 5 % glucose solution (GLU); iii) synthetic muramyl dipeptide analogue (MDP); and iv) lipopolysaccharide (LPS), administered into the mammary gland lumen. Leukocytes from mammary glands were obtained by mammary gland lumen lavages after influx induction. The total cell counts in lavages increased after treatment by all inducers in comparison to the counts before influx induction (P<0.001). Cell counts were higher and differed significantly by MDP and LPS (P<0.01) in contrast to PBS. The highest proportion of neutrophils was induced by LPS (P<0.01). After three-hour incubation, light microscopy examination revealed the highest manifestation of neutrophil apoptosis after induction by GLU (P<0.05). The lowest apoptosis manifestation, though statistically non-significant, was detected after induction by MDP and LPS. Determination of early manifestation of neutrophil apoptosis revealed the lowest manifestation of neutrophil apoptosis after induction by LPS (P<0.01). The results of late manifestation of neutrophil apoptosis revealed the highest proportion of apoptotic neutrophils after induction by GLU (P<0.05). The manifestation of secondary necrosis of apoptotic neutrophils or neutrophil lysis after 3 h of incubation was low and not significant. In conclusion, certain inducers of neutrophil migration into the lumen of bovine mammary glands (GLU and LPS in the present experiments) significantly influence the manifestation of neutrophil apoptosis during their subsequent in vitro incubation.

Effects of certain inducers of leukocytes migration into the bovine mammary gland on neutrophil apoptosis manifestation in a subsequent in vitro cultivation

The aim of the study was to elucidate the effects of induced leukocyte migration into the bovine mammary gland on the manifestations of early and late apoptotic features of neutrophils cultivated in vitro. The Latin square design was used in two experiments, each involving four experimental repetitions in 4 clinically healthy virgin heifers. The neutrophil early apoptotic features were detected by flow cytometric detection (FCM) of phosphatidyl-serine translocation. Late neutrophil apoptotic features were detected by ELISA quantitation of histone-complexed DNA fragments. Leukocyte influx induction was accomplished by using four inducers: i) sterile buffered saline solution (PBS); ii) 5 % glucose solution (GLU); iii) synthetic muramyl dipeptide analogue (MDP); and iv) lipopolysaccharide (LPS), administered into the mammary gland lumen. Leukocytes from mammary glands were obtained by mammary gland lumen lavages after influx induction. The total cell counts in lavages increased after treatment by all inducers in comparison to the counts before influx induction (P<0.001). Cell counts were higher and differed significantly by MDP and LPS (P<0.01) in contrast to PBS. The highest proportion of neutrophils was induced by LPS (P<0.01). After three-hour incubation, light microscopy examination revealed the highest manifestation of neutrophil apoptosis after induction by GLU (P<0.05). The lowest apoptosis manifestation, though statistically non-significant, was detected after induction by MDP and LPS. Determination of early manifestation of neutrophil apoptosis revealed the lowest manifestation of neutrophil apoptosis after induction by LPS (P<0.01). The results of late manifestation of neutrophil apoptosis revealed the highest proportion of apoptotic neutrophils after induction by GLU (P<0.05). The manifestation of secondary necrosis of apoptotic neutrophils or neutrophil lysis after 3 h of incubation was low and not significant. In conclusion, certain inducers of neutrophil migration into the lumen of bovine mammary glands (GLU and LPS in the present experiments) significantly influence the manifestation of neutrophil apoptosis during their subsequent in vitro incubation.

Impairment of the Peripheral Lymphoid Compartment in Iron-deficient Piglets

The aim of this study was to investigate the effect of neonatal iron deficiency on immune functions in young piglets. While control piglets were not given any iron preparation until the age of 21 days, another group of piglets was given 200 mg of Fe(3+)-dextran i.m. on day 3. Red blood cell parameters in the former, iron-deficient group were characteristic of hypochromic anaemia. In addition, the total leucocyte count (P < 0.01), relative and absolute neutrophil count (P < 0.01) and absolute lymphocyte count (P < 0.05) in peripheral blood were found significantly lower in iron-deficient piglets than in their iron-supplemented counterparts. Lymphocyte activity as measured by in vitro lymphocyte transformation test was impaired in iron-deficient piglets. A statistically significant decrease in circulating B-lymphocyte numbers was found in non-supplemented animals. Iron deficiency apparently negatively influenced the immunocompetence in piglets.

Chromium Supplementation Enhances Antibody Response to Vaccination with Tetanus Toxoid in Cattle

Nineteen multiparous late-pregnant dairy cows were divided into an experimental group (n = 10) and a control group (n = 9). Animals in the experimental group were fed a diet supplemented with chromium chelate admixed into wheat meal at 5 mg per animal per day. The supplementation was started 4 weeks before calving and stopped by the end of week 3 after calving. All the cows were vaccinated with tetanus toxoid in the fifth and sixth week of lactation. Monitoring of the characteristics of non-specific immunity did not show any significant between-group differences in total and differential leucocyte counts, percentages of lymphocyte subpopulations, activities of lectin-stimulated lymphocytes, phagocytic activities, and the contents of total immunoglobulins and lysozyme in blood sera. Tetanus toxoid-specific antibody titres, those of the IgG2 isotype in particular, were higher in the experimental group than in the control animals. These results indicate that chromium supplementation at the level used in this experiment modulated the regulation of functions of the immune system.

Postnatal development of leukocyte subset composition and activity in dogs

The aim of the presentation is to summarise our data on the counts and activity of circulating canine leukocytes at birth and on their changes in the first 3 months of life. On day 1, neutrophil counts were almost three times higher than lymphocyte counts. During the first week of life, a decrease of neutrophil and an increase of lymphocyte counts, resulting in a predominance of lymphocytes, were observed. Neutrophil counts reached values comparable with those in adults in 1 month. Lymphocyte counts were higher than those in adults during the first 3 months. From birth to the age of 3 months, the phagocytic activity of neutrophils was nonsignificantly higher than in young adults. When compared with adults, the peripheral blood of new-born pups contained a lower proportion of T lymphocytes (detected by CD3 and CD5 markers), with a very low percentage of CD8(+) cells and a higher proportion of CD21(+) B lymphocytes. The counts of individual subsets levelled out during the first 3 months of life, although the proportion of CD21(+) B cells remained higher all the time. Lymphocytes of new-born pups were able to respond to nonspecific mitogen stimulation. Spontaneous proliferation in vitro was higher during the first week of life. Although in vitro stimulation of lymphocytes with Concanavalin A in some pups was comparable with that of adult dogs, mean activity was weaker. Pups with zero or very low levels of maternal antibodies were able to develop specific immune responses to a parvovirus antigen as early as at 2 weeks of age. On the basis of these data, we assume that pups are born with an immune system that can respond to external stimuli. Nevertheless its development continues in the postnatal period and some parameters differ from adult values for at least 3 months after birth.

Lymphocyte subsets in peripheral blood of dogs--a flow cytometric study

Slight differences in the results of papers describing lymphocyte subsets distribution in the peripheral blood of healthy dogs may be explained by differences in monoclonal antibody clones and sources, breed and age of animals examined, methods of sample treatment, or methods of result analysis. In this paper, we described the effect of sample processing and of sample storage as well as the effect of age, breed, and gender of dogs on lymphocyte subset distribution. No significant differences were found between samples processed following a whole-blood lysis method and samples processed after density gradient separation. Furthermore, no significant differences were found between samples processed within 2h after collection and those stored at 4 degrees C for 12-16 h before processing. Age-related changes were evident in lymphocyte subset distribution in the peripheral blood of 38 Beagles divided according to their age into the six groups: (1) 5-6 days; (2) 2 months; (3) 6 months; (4) 1-2 years; (5) 3-5 years; and (6) >5 years. The percentage of B-lymphocytes (CD21-like positive cells) in the peripheral blood of newborn pups was 39.5+/-5.7 and decreased with advancing age. The percentage of CD8+ lymphocytes was 7.7+/-3.4 after birth and increased with advancing age. No age-related changes were observed in the percentages of CD4+ lymphocytes. The CD4+:CD8+ ratio decreased with advancing age. No significant age-related change was observed for lymphocytes bearing the gammadelta-TCR. Some breed differences were evident. Adult (1-5-year-old) Beagles, German Shepherds, Dalmatians, and Dachshunds were examined. The percentages of lymphocytes were higher in Beagles and Dachshunds than in Dalmatians and German Shepherds. The highest and the lowest absolute lymphocyte counts were found in Beagles and German Shepherds, respectively. As a consequence, German Shepherds showed the lowest absolute counts of the individual lymphocyte subpopulations and the widest neutrophil:lymphocyte ratio. Dalmatians showed the lowest percentage of CD3+ cells, the highest percentage of CD21+ cells, and the lowest CD4+:CD8+ ratio. German Shepherds showed the lowest percentage of CD21+ cells and the highest CD4+:CD8+ ratio. Females in Beagles and Dachshuns had nonsignificantly higher percentages of total lymphocytes, CD3+, CD4+, and nonsignificantly lower percentages of CD21+ lymphocytes. We concluded that there are age-, breed-, and perhaps also gender-related differences in lymphocyte subset distribution in the peripheral blood of dogs. Therefore, there is need to use appropriate control group in the experimental protocols. Among-breed differences could explain, at least partly, breed predisposition for some diseases.

Immunosuppression in bitches with pyometra

The function of the immune system was studied in 34 bitches affected by pyometra. The mean age of the animals was 8.1 +/- 2.8 years. Samples of peripheral blood were examined using a battery of immunological tests. Data obtained from four sets of animals, grouped according to the severity of their disease, were compared. Leucocytosis (neutrophilia and partial monocytosis) and lymphopenia were detected in 62 per cent and 35 per cent of the bitches, respectively. The increase in the number of leucocytes was higher in the severely affected bitches. Inhibition of mitogen-driven lymphocyte proliferation was the characteristic feature of the immunological profile in bitches affected by pyometra, and this corresponded with the impairment of the general state of health. Sera from bitches showing functional inhibition of lymphocytes suppressed the activity of lymphocytes isolated from normal dogs. Sera from bitches affected by pyometra also had higher levels of immunoglobulins, lysozyme and circulating immune complexes. It can be concluded that pyometra is associated with an inflammatory response, but also with a marked suppression of immune system activity.

Fatal toxoplasmosis in brown hares (Lepus europaeus): possible reasons of their high susceptibility to the infection

Brown hares (Lepus europaeus) trapped in the countryside and domestic rabbits were experimentally infected with Toxoplasma gondii (K7 strain) oocysts. Hares (n=12) were divided into groups of 4 and infected with 10, 10(3) and 10(5) oocysts. Rabbits (n=12) were infected in the same way. The experimentally infected animals were monitored for 33 days after infection (p.i.). Most of the infected hares demonstrated behavioural changes, and all of them died between 8 and 19 days p.i. Three of the rabbits demonstrated only clinical changes related to the concurrent pasteurellosis. The typical pathological finding in the hares were haemorrhagic enteritis, enlargement and hyperaemia of mesenteric lymph nodes, splenomegaly and multiple miliary necrotic lesions in the parenchyma of the liver and other organs. Pathological changes in the rabbits were less pronounced than in the hares. In rabbit brains, tissue cysts of the T. gondii were found. The incidence of T. gondii antibodies both in the hares and the rabbits was first ascertained on day 7 p.i. On day 12 p.i., antibodies were already found in all the animals infected. Antibody titres in indirect fluorescence antibody test (IFAT) using the anti-rabbit conjugate were markedly higher in rabbits than in hares. In all hares, T. gondii was isolated post mortem from the liver, brain, spleen, kidney, lung, heart and skeletal muscles. Although T. gondii was also isolated in all rabbits, it was not always isolated in all their organs. In all hares, parasitemia was demonstrated on days 7 and 12 p.i. The percentage of rabbits with detected parasitemia was lower. In hares, a decrease in the numbers of leukocytes during the infection was observed. No such decrease was observed in the rabbits. The lymphocyte activity after the stimulation with non-specific mitogens showed significant differences between the hares and the rabbits even before the infection. After the infection, the hares infected with 10(3) and 10(5) doses and in rabbits infected with a 10(5) dose showed a decrease of lymphocyte activity. Rabbits infected with a 10(3) dose showed an increase of the lymphocyte activity. While in hares toxoplasmosis was an acute and fatal disease, the infection in rabbits had subclinical manifestations only and easily passed to a latent stage. The different courses of toxoplasmosis in the hare and the rabbit may be due to the differences in the natural sensitivity of the two species to the T. gondii infection or a negative impact of stress to the immune status of hares.

Immunosuppression in dogs with pyoderma and/or demodicosis

The occurrence of decreased activity of the immune system was studied in a group of 66 dogs with various combinations of pyoderma and demodicosis. Our complex examination of the dogs included the following: leukocyte count, differential count, phagocytosis, blastogenic lymphocyte transformation and quantitation of total serum immunoglobulins, lysozyme and haemolytic complement. Immunosuppression was found in 19 (28.8%) cases. Immunosuppression was rare in dogs with demodicosis and did not appear without a concurrent pyoderma. An increase in the neutrophil counts and total serum immunoglobulin levels significant was found in dogs with demodicosis combined with pyoderma. On the contrary, marked immunosuppression was detected in dogs with deep pyoderma. A considerable immunosuppression was present in 7 of 10 German shepherds dog pyoderma (GSP). Significant depressions were found in phagocyte activity and lymphocyte activity. Immunosuppression was observed in 4 of 9 dogs in other breeds with uncomplicated deep pyoderma. All groups of dogs with pyoderma showed a significant increase in total serum immunoglobulins. Conclusion from these findings is that deep pyoderma more than Demodicosis was concerned with immunosuppression. German shepherds with deep pyoderma had more expressed immunosuppression than other breeds.