Učinak odabranih makrolida na neka obilježja goveđih leukocita

The aim of the study was to evaluate the effect of tylosin, tilmicosin and roxithromycin on viability, nitro blue tetrazolium reduction (NBT) assay, chemotaxis, apoptosis and oxidative stress in bovine leukocytes in vitro conditions. The material for the study consisted of blood collected into EDTA tubes from the external jugular vein of Holstein-Friesian cattle aged 1 week to 2.5 years, during routine veterinary examinations. In leukocytes the percent of viability, nitrate ion concentration (NO), metabolic activity (NBT, nitrotetrazolium blue reduction assay), chemotactic activity and apoptosis were determined. The results indicated a slight negative effect of these macrolides on the viability of the leukocytes, and confirmed the ability of macrolides to induce apoptosis in leukocytes in vitro. These results indicate that all of the macrolides investigated exhibit a modulatory effect on the functions of leukocytes isolated from cattle of different ages. The strongest inhibitory effect on the NBT reduction assay and chemotaxis of the leukocytes was exhibited by roxithromycin, which at the same time had the least negative effect on the leukocytes.Cilj je ovog istraživanja bio procijeniti učinak tilozina, tilmikozina i roksitromicina na preživljavanje, test redukcije “nitro-tetrazol-modrog” (NBT), kemotaksiju, apoptozu i oksidacijski stres goveđih leukocita u uvjetima in vitro. Prilikom rutinskog veterinarskog pregleda, u epruvete s EDTA bila je uzeta krv iz jugularne vene goveda holštajnsko-frizijske pasmine u dobi od tjedan dana do 2,5 godine. Određen je postotak preživljavanja leukocita, koncentracija iona nitrata (NO), metabolička aktivnost (test redukcije “nitro-tetrazol-modrog”, NBT), kemotaksijska aktivnost i apoptoza. Rezultati su pokazali blagi negativni učinak spomenutih makrolida na preživljavanje leukocita i potvrdili sposobnost makrolida da potaknu njihovu apoptozu in vitro te naznačuju da svi pretraženi makrolidi imaju modulacijski učinak na funkciju leukocita goveda različite dobi. Najjači inhibicijski učinak na test redukcije NBT i kemotaksiju leukocita pokazao je roksitromicin, koji je istodobno imao najmanje negativan učinak na leukocite

Mechanisms of tumour escape from immune surveillance

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

Phagocytic activity and oxygen metabolism of peripheral blood granulocytes from rabbits experimentally infected with Trichophyton mentagrophytes

Phagocytic activity and oxygen metabolism of peripheral blood granulocytes from rabbits with experimental trichophytosis were assessed by flow cytometry

Comparative evaluation of cytokine and acute-phase protein concentrations in sera of dairy cows with subclinical and clinical ketosis as a different view of the causes of the disease

Background and Aim: Ketosis is a common disease occurring during the first stage of lactation in highly productive dairy cows. The aim of the present study was the comparative assessment of selected pro-inflammatory cytokines (including tumor necrosis factor-α [TNF-α] and interleukin 6 [IL-6]), anti-inflammatory cytokines (including IL-10), and acute-phase proteins (APPs) (including haptoglobin [Hp] and serum amyloid A [SAA]), in the sera of cows with subclinical ketosis (SCK), in those with clinical ketosis (CK), and in healthy cows. Materials and Methods: Thirty dairy cows of Holstein-Friesian breed were investigated. The cows were divided into three groups depending on the serum β-hydroxybutyric acid (BHBA) level. The control, SCK, and CK groups included healthy cows, cows with SCK, and cows with CK, respectively. BHBA concentration in blood serum was determined using colorimetric method. The blood serum was used for proper tests. Cytokine (TNF-α, IL-6, and IL-10) and APPs (SAA and Hp) concentrations in the investigated samples were determined by enzyme-linked immunosorbent assay method. Results: The SCK group had significantly higher TNF-α, IL-6; IL-10, and SAA values than had the CK group (p<0.01). The SCK group had a lower Hp concentration than had the CK group (p<0.05). Conclusion: This study showed that the inflammation intensity is higher in the initial phase of the disease and decreases during the advancement, probably due to active anti-inflammatory mechanisms (an increase of IL-10 concentration), which protect animal organism from self-destruction. On the basis of our study, it can be assumed that ketosis development in dairy cows was preceded by the systemic inflammation that may influence the progress of this disease

Comparative Expression Analysis of Innate Immune Markers and Phagocytic Activity in Peripheral Blood of Dogs with Mammary Tumors

Canine innate immune system role in cancer prevention and progression remains poorly understood. It has been revealed that innate immune cells could play a dual role in cancer immunology promoting or inhibiting tumor development and growth. Current immunotherapies target mainly the adaptive anti-tumor response and that may be a reason why they remain ineffective in a majority of patients. It is important to acquire detailed knowledge about innate immune mechanisms to broaden the diagnostic and therapeutic options and employ innate immune cells in anti-cancer therapies. In the present study, 21 female dogs of different breeds and types of spontaneous mammary tumors were investigated. The study aimed to find simple and cheap markers that can be used for preliminary diagnosis, prior to the surgical resection of the tumor. The differences in innate immune cell quantity and function were investigated between female dogs with malignant mammary tumors of epithelial and mesenchymal origin. Flow cytometry was used to evaluate the percentages of CD5+ lymphocytes including CD5low lymphocytes, CD11b integrin expression on leukocytes, phagocytosis, and oxidative burst. The number of CD11b lymphocytes was increased in tumors with epithelial origin compared to the control group. No significant differences were found between the percentages of phagocytic cells neither for granulocytes nor for monocytes. However, the phagocytes of canine patients with tumors of epithelial origin showed increased phagocytosis compared to the control group. The percentages of granulocytes that produced reactive oxygen species (ROS) in response to E.coli and PMA were not altered in patients with malignant tumors compared to control. A statistically significant difference between the number of ROS produced by the single granulocyte was demonstrated only between the group of bitches with epithelial tumors and the control group in case of E. coli stimulation. The obtained results suggest that some innate immune cells may be involved in anti-tumor immune mechanisms and have the potential to be supportive diagnostic markers in canine mammary tumors

Shortbread Cookies Enriched with Micronized Oat Husk: Physicochemical and Sensory Properties

Oat (Avena sativa L.) by-products are valuable sources of many bioactive compounds and minerals. This paper aimed to study the possibility of using micronized oat husk (hull) as a partial replacement for wheat flour (at levels 5, 10, 15, and 20%) in shortbread production. The physicochemical and sensory properties of control and enriched cookies were studied. The incorporation of oat husk into shortbread increased the fiber and ash content, and decreased the available carbohydrates in the cookies. The color of the enriched shortbread significantly changed and the total color difference between the control and enriched cookies ranged from 4.76 to 11.00. Moreover, the total phenolics content and antioxidant activity linearly increased with the percentage of husk in the cookie recipe. Importantly, micronized oat husk at a level of 20% had little influence on the sensory acceptability of cookies. However, replacement of wheat flour higher than 10% resulted in a harder texture of cookies and lower scores for this attribute were obtained. To summarize, in this work we showed that micronized oat husk can be a valuable additive for cookie fortification

Shortbread Cookies Enriched with Micronized Oat Husk: Physicochemical and Sensory Properties

Oat (Avena sativa L.) by-products are valuable sources of many bioactive compounds and minerals. This paper aimed to study the possibility of using micronized oat husk (hull) as a partial replacement for wheat flour (at levels 5, 10, 15, and 20%) in shortbread production. The physicochemical and sensory properties of control and enriched cookies were studied. The incorporation of oat husk into shortbread increased the fiber and ash content, and decreased the available carbohydrates in the cookies. The color of the enriched shortbread significantly changed and the total color difference between the control and enriched cookies ranged from 4.76 to 11.00. Moreover, the total phenolics content and antioxidant activity linearly increased with the percentage of husk in the cookie recipe. Importantly, micronized oat husk at a level of 20% had little influence on the sensory acceptability of cookies. However, replacement of wheat flour higher than 10% resulted in a harder texture of cookies and lower scores for this attribute were obtained. To summarize, in this work we showed that micronized oat husk can be a valuable additive for cookie fortification

Analysis of the Leukocyte Response in Calves Suffered from Mycoplasma bovis Pneumonia

Mycoplasma bovis is known to be a cause of chronic pneumonia in cattle. To date, the disease pathomechanism has not been fully elucidated. Leukocytes play a key role in host antimicrobial defense mechanisms. Many in vitro studies of the effect of Mycoplasma bovis (M. bovis) on leukocytes have been performed, but it is difficult to apply these results to in vivo conditions. Additionally, only a few studies on a local immune response in M. bovis pneumonia have been undertaken. In this study, the experimental calf-infection model was used to determine the effect of field M. bovis strains on changes of the peripheral blood leukocyte response, including phagocytic activity and oxygen metabolism by cytometry analyses. An additional aim was to evaluate the lung local immunity of the experimentally infected calves using immunohistochemical staining. The general stimulation of phagocytic and killing activity of peripheral blood leukocytes in response to the M. bovis infection points to upregulation of cellular antimicrobial mechanisms. The local immune response in the infected lungs was characterized by the T- and B-cell stimulation, however, most seen in the increased T lymphocyte response. Post-infection, strong expression of the antigen-presenting cells and phagocytes also confirmed the activation of lung local immunity. In this study&mdash;despite the stimulation&mdash;both the peripheral and local cellular antimicrobial mechanisms seem to appear ineffective in eliminating M. bovis from the host and preventing the specific lung lesions, indicating an ability of the pathogen to avoid the host immune response in the M. bovis pneumonia

Phagocytic Activity, Oxygen Metabolism and Serum Amyloid a Concentration in Peripheral Blood of Mink with Subclinical Aleutian Virus Infection

Aleutian disease (AD) is a chronic disease of mink caused by the Aleutian Mink Disease Virus (AMDV) that results in dysfunction of the immune system. The prevalence of asymptomatic AMDV infections suggests a necessity to explore their effects on the cellular mechanisms of non-specific immunity in farmed mink. The study evaluated the phagocytic activity and oxygen metabolism of peripheral blood granulocytes and monocytes in mink with chronic subclinical AMDV infection. Moreover, the intensity of inflammatory processes was assessed based on the serum amyloid A (SAA) concentration. The analyses involved 24 brown mink females aged 12–24 months. The experimental group (group I) consisted of mink with chronic subclinical AMDV infections, and the control group (group II) included healthy animals. The statistical analysis was performed using the Mann-Whitney U rank test. Phagocytic activity of granulocytes and monocytes was carried out using flow cytometry, and SAA concentration was determined with enzyme-linked immunosorbent assay (ELISA). Compared with the control group, there was a significant decrease in the phagocytic activity and oxygen metabolism of granulocytes and monocytes in the AMDV-infected mink (p p < 0.05). The obtained data indicate that monitoring the serum SAA levels in mink with asymptomatic inflammation may help assess the health of mink and detect asymptomatic inflammation caused by AMDV infection