The association of C789A polymorphism in the dopamine beta-hydroxylase gene (DBH) and aggressive behaviour in dogs

The genetic basis of aggressive behaviour has been examined extensively, including analysis of genes encoding neurotransmitters, signalling molecules and regulatory enzymes, as well as their synthesis and degradation. Dopamine beta-hydroxylase, an enzyme catalysing the conversion of dopamine into norepinephrine in synaptic endings, significantly affects the modulation of emotional states and behaviour. The aim of this study was to determine the association of C789A polymorphism in the canine dopamine beta-hydroxylase gene (DBH) and aggressive behaviour in dogs. A total of 110 dogs of different breeds were analysed. All animals were classified according to their individual behavioural characteristics, defined by a veterinary interview and observation. Polymorphism was analysed using ACRS-PCR (amplification created restriction site-polymerase chain reaction) method. Significant differences in DBH genotypes and allele frequency between aggressive and non-aggressive dogs were observed (χ2 = 16,232, P = 0.0003). In aggressive dogs, the CC genotype (0.788) and C allele (0.815) were most frequent while in non-aggressive dogs, their frequencies were significantly lower (0.361 and 0.404, respectively). The obtained results indicate that DBH is a promising candidate gene for canine behavioural study.

Cytotoxic effect of Aeruginosin-865, capsaicin, and resveratrol on mouse cell lines of different origin

The aim of the study was to compare the effects of three natural bioactive compounds (and their combinations) on normal vs. tumour-transformed mouse cells. The cytotoxic effect of Aeruginosin-865 (Aer), capsaicin (Cap), resveratrol (Res) and their combinations was evaluated on normal hepatocytes (AML) and tumour cells derived from livers (Hepa) and kidneys (Renca). Various concentrations from 25 to 200 μM of tested substances were used. Only the Aer + Res combination and a low concentration of Res had a significant cytotoxic effect on Hepa and Renca and no significant cytotoxic effect on AML. Cap had a significant cytotoxic effect on all tested cell lines, but tumour-derived cells showed higher resistance than AML. A significantly increased cytotoxicity was found in the combination of Cap + Res compared to each substance alone. All types of cells showed similar sensitivity to the cytotoxic effect of Cap + Res. Because of a possible hepatotoxic effect, we recommend further investigations into side-effects of Cap + Res. No cytotoxic effect was described in Cap + Aer or in Aer alone. Only substances with a significant cytotoxic effect on tumour cells and no cytotoxic effect on normal cells can be potentially used in anticancer treatment. According to the results, only Res or the combination of Aer + Res can be recommended for further evaluation in the process of new anticancer drug development. The potential hepatotoxic effect of Cap + Res can significantly limit the utilisation of these substances in anticancer treatment.

Reproductive toxicity of heavy metals in fallow deer in vitro

Sertoli cells play a crucial role in male fertility through boosting and regulating the differentiation of spermatogonial stem cells into mature sperm during spermatogenesis. Female ovarian follicles are responsible for the production of mature ova and control of ovarian steroidogenesis. Disruption of these structures through exposure to environmental pollutants is critical for reproductive health. Here, we derived primary cell cultures of Sertoli cells and ovarian follicles from fallow deer (Dama dama). Cells were used as in vitro models to explore reproductive toxicity of heavy metals in wild species. Adverse effects of cadmium (CdCl2), methylmercury (MeHgCl2), and lead (PbCl2) were investigated through a range of equal molar concentrations (0, 15, 30, 60, 125, 250 µM). We found both concentration-dependent and independent cytotoxic patterns (P < 0.01, P < 0.05) in cells exposed to CdCl2, MeHgCl2, and PbCl2. Based on generation of lipid hydroperoxides, significant levels of cell oxidative perturbation were detected in the CdCl2 (P = 0.0001), PbCl2 (P = 0.001), and MeHgCl2 (P = 0.003) groups. Likewise, the antioxidant enzymes catalase and glutathione peroxidase were inhibited in all metal-treated groups (P < 0.01). Genotoxic DNA damage (single-strand break) was also observed (MeHgCl2 group, P = 0.002; CdCl2 and PbCl2 groups, P = 0.004). Increased activity of superoxide dismutase (P = 0.0002 and P = 0.01) was observed in MeHgCl2 and CdCl2, respectively. Cell apoptosis was detected in all the PbCl2 and CdCl2 (P = 0.00007) and MeHgCl2 (P = 0.001) groups. The results of this study can be used to characterize the responsiveness of fallow deer gonadal cells to the stress of toxic metal exposure.

Radiographic measurement of canine stifle joint angles using four different landmark methods

This study was conducted to compare angles physically set on the stifle joints of cadaveric limbs of dogs with the results by four different radiographic methods for stifle angle measurement. Thirteen pelvic limbs from various large breeds and skeletally-mature dogs were used. The stifles were fixed at four angles: 125°, 130°, 135° and 140°. Altogether 52 radiographs were done. Each stifle angle set on the cadaver limbs was radiographically measured using four sets of landmarks (the goniometric, long axis, eminence and kinematic methods). We found similarity between angles physically set on cadaver limbs and radiographically measured using the long axis method (P > 0.05). The goniometric method showed similarity in group of limbs with the stifle fixed at 140° (P > 0.05), and other measurements differed significantly (P < 0.05). Eminence and kinematic method measurements were different compared to the angle of fixation of the stifle on the cadaver (P < 0.05) but similar compared to each other (P > 0.05). The method of stifle joint angle measurement should be considered when comparing similar studies, and also in pre-operative measurements for some tibial osteotomies aimed at stabilizing the joint after cranial cruciate ligament rupture.

The influence of haemolysis on the determination of vitamin E in cattle

The study deals with the influence of haemolysis on the results of vitamin E determination in plasma (serum) in cattle. Although nowadays specific High Performance Liquid Chromatography (HPLC) techniques are used almost exclusively for the determination of vitamin E, this indicator is also influenced by haemolysis. This occurs in the pre-analytical phase due to the fact that iron contained in haemoglobin is able to catalyze peroxidation reactions. Subsequently, changes occur mainly in polyunsaturated fatty acids in the lipoprotein components of serum/plasma. The vitamin E present inhibits this process, as a result of which its concentration is reduced. The experiment was performed by preparing model samples with a defined degree of haemolysis by adding haemolysate to the centrifuged plasma in the range of ca 0–12 g/l, i.e. mild to severe haemolysis. After 4 h of incubation at room temperature, the vitamin E concentration was determined by the HPLC method. Haemolysis was found to reduce the test result; mild one (approximately up to 2 g/l) non-significantly, medium and severe haemolysis by up to tens of percent, which warrants repeated sampling. False reductions in results will not endanger the patient’s health, but economic losses may occur due to unnecessary check-ups and increased vitamin E supplementation.

Comparison of the effect of two anti-adhesion materials on the formation of postoperative adhesions after myomectomy – an experimental study on rabbit does

This study compares the effect of Hyalobarrier Gel and 4DryField® PH on the formation of postoperative adhesions after myomectomy in an experimental study on rabbit does. Thirty experimental animals were divided into three groups: group A – control, group B – use of 4DryField® PH, and group C – use of the Hyalobarrier Gel. A simulated myomectomy was performed in each group. The animals were euthanised 14 days after the procedure and the antiadhesive effect of the above-mentioned preparations was evaluated according to the criteria. Statistical evaluation clearly showed differences in the antiadhesive effect in the scoring systems for groups B and C compared to control group A at a high level of significance. We demonstrated an obvious, statistically confirmed antiadhesive effect of the Hyalobarrier Gel and 4DryField® PH in an experimental model of the rabbit uterus. Comparing both preparations, the Hyalobarrier Gel shows a higher level of effectiveness. Based on the results of the experiment, both preparations can be unambiguously recommended for routine practice.

The effects of buccal administration of azaperone on the sedation level and biochemical variables of weaned piglets

The aim of the study was to compare the efficacy of buccal and parenteral administration of azaperone in order to achieve pig sedation. The type of study was prospective randomized and double blinded. A total of 40 weaned piglets were divided into 4 groups (10 each) and monitored. Group A was injected intramuscularly (i.m.) with azaperone (Stresnil®, 40 mg/ml inj., Elanco Animal Health) at a dose of 2 mg/kg body weight (b.w.). Group B (control) was given 1 ml of saline buccally. Group C received a dose of 2 mg/kg b.w. of azaperone buccally. Group D was given azaperone buccally at a dose of 4 mg/kg b.w. The response to defined stimulus (a blunt blow of a metal rod into the metal edge of the pen), degree of salivation, movement level, blood plasma azaperone concentration, and the haematological and biochemical variables were included in the study. We found that the buccal administration of azaperone is effective, however, a dose of 4 mg/kg b.w. is required to induce a sedation level comparable to the standard 2 mg/kg b.w. i.m. administration.

Influence of pentoxifylline and caffeine on stallion epididymal sperm motility after thawing

Two substances at two concentrations each were added to frozen-thawed stallion epididymal spermatozoa to improve motility indicators, which were assessed 30, 60, 120, 180 and 240 min after thawing. Pentoxifylline was added at concentrations of 3.6 mM (1 mg/ml) and 7.18 mM (2 mg/ml). Both concentrations had a positive effect on total and progressive motility of spermatozoa throughout the study. The other substance, caffeine, was added at concentrations of 2 mM (0.4 mg/ml) and 5.5 mM (1 mg/ml). Both concentrations had a positive effect on total and progressive motility of spermatozoa only 30 and 60 min after thawing. Subsequently, 180 min after thawing, improvement was found only in total sperm motility.

Effect of electromagnetic radiation on the liver structure and ultrastructure of in utero irradiated rats

The aim of this study was to observe the influence of electromagnetic radiation (EMR) on the structure and ultrastructure of the rat’s liver. The pregnant rats used in the experiment were exposed to a pulsed microwave radiation (frequency of 2.45 GHz; mean power density of 2.8 mW/cm2) daily for 2 h, throughout their pregnancy. After delivery, the offspring was not exposed to EMR. Samples of the liver of 5-week-old offspring were subjected to histopathological evaluation. They were processed for light and transmission electron microscopy. Our results indicated that EMR did not cause pronounced changes in the structure of the liver of the investigated offspring. The size and shape of liver lobuli was preserved and the amount of connective tissue in the liver parenchyma did not increase. However, electron microscopy revealed changes in the shape and number of microvilli at the vascular pole of hepatocytes, and formation of vesicles of various shapes and sizes. The endothelial cells were swollen with larger fenestrations compared to the control group. The spaces of Disse were irregular and dilated. Even though these changes were only mild, further studies are needed to determine the effect of EMR and clarify its potential risk during pregnancy.

Unprocessed milk as a source of multidrug-resistant Staphylococcus aureus strains

Staphylococcus aureus is the most relevant pathogen of animal mastitis and milk-related intoxications. Its presence in directly sold milk is rather not to be expected if strict udder health management and regular microbiological control of raw milk are performed. In this one-year survey, we present the results of monthly microbiological testing of milk from vending machines in Croatia for S. aureus and its multi-drug resistance. Staphylococcus aureus was detected in 27.58% of the samples. Among 60 tested isolates from 10 farmers, a total of 41 isolates were resistant to at least one antimicrobial agent (68.33%). A Multiple Antibiotic Resistance (MAR) index of 0.2 or higher had 48.8% of the resistant isolates, which is considered a high-risk potential for the spread of antimicrobial resistance. The majority of the isolates were resistant to penicillin and ampicillin followed by ciprofloxacin, ceftazidime, and kanamycin. The results impose the need for improving the control measures in the raw milk distribution chain focused on MAR risk reduction.