Journal of Veterinary Research最新文献

Introduction: This study investigated the effects of intragastric administration of apelin-13 on the secretion of critical pancreatic hormones in a cohort of three-week-old Wistar rats. The research aimed to uncover apelin's modulatory roles in endocrine interactions dictating metabolic homeostasis during early life.

Material and methods: Rats were randomly assigned to control or experimental groups, receiving apelin-13 or saline for 14 days. The study population consisted of three-week-old Wistar rats of both sexes, weighing between 20 and 25 grams. Histological examination, analysis of variance and t-tests were employed to assess significant differences.

Results: Distinctive alterations in large islet morphology were observed, indicating a notable reduction in size. Additionally, an increase in alpha- and beta-cell density within specific islet sizes was noted, suggesting significant changes in cell populations. The study found a substantial increase in mitotic activity and a decrease in apoptosis in small and medium-sized islets post apelin-13 administration, indicating its potential role in regulating cell survival and proliferation.

Conclusion: The notable reduction in large islet size coupled with increased alpha and beta cell density implies a targeted impact of apelin-13 on pancreatic cell dynamics. Also, the observed increase in mitotic activity and decrease in apoptosis in small and medium-sized islets suggest its potential regulatory role in cell survival and proliferation within the pancreatic microenvironment.

Introduction: Microsporum canis is a dermatophyte that mainly affects dogs and cats. However, it can be transmitted to humans by direct contact. This makes it one of the most frequent causative agents of dermatophytosis in humans, reflecting the frequent human close relationships with pets. Conventional treatment relies on antifungal pharmacological agents. However, errors in application have led to the occurrence of fungal resistance and toxic effects. Consequently, new therapeutic alternatives are needed for M. canis infections. Plant extracts have been explored as phytotherapeutics for the treatment of dermatophyte infections, which prompted an attempt to apply extracts of the ethnopharmacologically important plants Artemisia ludoviciana and Cordia boissieri.

Material and methods: Methanolic extracts of these two plants were obtained using a Soxhlet method and were characterised by phytochemical screening. Extracts were evaluated against a M. canis commercial strain (ATCC-11621) using the microdilution method described in the Clinical and Laboratory Standards Institute protocol M38-A, determining its minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC). Subsequently, these concentrations were tested in a human keratinocyte human cell line.

Results: Artemisia ludoviciana and C. boissieri extracts showed MIC values of 2,500 and 1,250 µg/mL, and MFC values of 5,000 and 2,500 µg/mL against M. canis, respectively. These extracts did not inhibit HaCaT cell proliferation in vitro.

Conclusion: The evaluated extracts showed potential for the treatment of M. canis fungal infections. However, further studies on their phytochemical characterisation, purification, clinical safety and formulation are required.

Introduction: The adulteration of wax foundation is, for many reasons, a growing problem of modern beekeeping not only in Europe but also around the world. Wax foundation contaminated with stearin addition leads to a brood die-off, while paraffin addition negatively affects the strength of combs. It is tenable that such adulterated wax foundation reduces bees' immunity. The aim of the study was to determine the activities of two bee immune enzymes, lysozyme and phenoloxidase, in the haemolymph of worker bees which had emerged from combs with wax foundations contaminated with stearin or paraffin.

Material and methods: Combs built with stearin- or paraffin-adulterated wax (both adulterants at concentrations of 10%, 30% or 50%) or pure wax (0% adulterated) foundations were placed in the colonies, one for each adulterant and percentage. The workers were marked upon emergence from these combs and those bees were introduced into one strong colony per adulterant and percentage. Phenoloxidase and lysozyme activities were determined in the haemolymph of 1-, 7- and 14-day-old workers.

Results: The higher the concentrations of stearin and paraffin in the wax foundation, the lower the phenoloxidase activities were. These activities increased with the bee age. In contrast, the trends in lysozymes were opposite. Paraffin seems to be less toxic than stearin.

Conclusion: Adulteration of wax foundation with even a small amount of stearin or paraffin has negative effects on the functioning of the bee.

Introduction: In dairy cattle, oxidative stress is a predominant problem associated with diseases and reproductive health issues. This study aimed to detect the variation in the antioxidant biomarkers by adding different concentrations of β-hydroxybutyric acid (BHBA) and sought to elucidate its effects on the gene expression levels of growth hormone (GH) and antioxidant biomarkers in bovine hepatocytes.

Material and methods: Four antioxidant biomarkers, namely malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH Px) were evaluated using commercially available bovine ELISA kits. The expression levels of the bovine GH, its receptor (GHR), insulin-like growth factor (IGF), IGF-1, IGF-1 receptor, CAT, SOD, GSH-Px and β-actin (as a reference) genes in liver cell culture were determined by reverse transcriptase-PCR assay.

Results: With the increase of BHBA concentration and culture time, the activities of SOD, CAT, and GSH Px biomarkers in hepatocytes decreased. However, the content of MDA in hepatocytes increased gradually with the increase of hepatocyte culture time and BHBA concentration. The qPCR results revealed that after adding BHBA, gene expression levels of GSH-Px, SOD and IGF biomarkers in hepatocytes began to differ in the culture groups at 12 h, whereas the gene expression level of the CAT and GHR biomarkers in hepatocytes began to differ at 6 h.

Conclusion: Quantitative PCR results showed that the BHBA significantly downregulated the expression levels of the GHR gene and CAT, GSH Px and SOD antioxidant biomarker genes.

Introduction: The occurrence of pesticide residues in animal products deserves attention because of the contamination by environmental pollutants and pesticides that may be present in the food that animals are fed. The goal of this work was the validation of a method for detection of residues of multiple classes of pesticide and determination of their residues in chicken breast fillets.

Material and methods: Gas chromatography with mass spectrometry was used for analysis. A modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method was put into practice for its validation and applied to real samples. The study optimised mass detection and investigated the effect of a freezing step during the preparation of samples. Pesticides were determined in samples from conventional and organic production.

Results: The impact of the matrix effect decreased, with the largest number of pesticides and satisfactory recovery determined by the application of mixed solvent acetonitrile and ethyl acetate for extraction. Detection of pesticide residues was achieved in a linear range between 5 and 50 µg/kg with satisfactory excellent correlation coefficients greater than 0.99. The recovery of all the pesticide residues ranged between 71.2 and 118.80%. The relative standard deviation was from 2.9% to 18.1% for all validated pesticide residues. The limits of quantification were in the range of 3.0-4.9 µg/kg. Out of 56 pesticide residues analysed in real samples, 5 were detected: α endosulfan, cypermethrin, endosulfan sulphate, permethrin and p,p´-dichlorodiphenyltrichloroethane (DDT) and their concentrations ranged from 4.9 to 15.2 µg/kg.

Conclusion: All tested samples were compliant with the evaluation criteria, and detected values of pesticide residues were lower than the maximum residual levels.

Introduction: Rabies is endemic in Europe and red foxes are the vector and reservoir of the rabies virus (RABV). Based on classification established in the early 1990s, four variants of the rabies virus have been distinguished in Europe. Rabies broke out in January 2021 in the Mazowieckie voivodeship in central north-eastern Poland. The virus spread rapidly, reaching the Świętokrzyskie voivodeship in the central southern part and the Lubelskie voivodeship in the eastern part in the next months. Nine rabies cases were reported in the Podkarpackie voivodeship in south-eastern Poland between 2021 and 2023, mainly in red foxes but also in dogs and wildcat. The aim of the study was the identification of RABV variants in wildlife and domestic animals in Poland between 2021 and 2023.

Material and methods: The study involved 157 animal brains tested positive for rabies using a fluorescent antibody test. From 10% w/v brain homogenates, RNA was isolated and full-length RABV genomes were high-throughput sequenced with an RABV-enriched approach. Complete genomes of RABV isolates were phylogenetically analysed and the variants were estimated.

Results: Molecular and phylogenetic studies revealed 147 (93.6%) of the RABV strains out of 157 which had rapidly spread in the wildlife of the Mazowieckie, Świętokrzyskie and Lubelskie voivodeships to be Central European strains. Nine RABVs (5.7%) detected in foxes, a wildcat and a dog in the Podkarpackie voivodeship were identified as North-Eastern European. A vaccine-induced rabies case was detected in a red fox in the Lubelskie voivodeship in May 2023.

Conclusion: Central European and North-Eastern European RABVs were circulating in Poland between 2021 and 2023.