Survival of Enterococcus hirae in ripened cheese subjected to ultra high pressure

The samples of a sliced, hard cheese were placed in commercially used polyamide-polyethylene bags, inoculated with E. hirae and sealed under vacuum. The samples were exposed to high hydrostatic pressure of 300, 400 and 500 MPa for 5, 10 and 15 min. The number of surviving E. hirae and Aerobic Plate Counts (APC) were determined. The bacterial counts were transformed to logarithms and D-values (time required for decimal reduction of E. hirae at given pressure) were calculated using linear regression method. It was found that numbers of E. hirae decreased with the increase of pressure and prolongation of treatment time. D-values amounted to: D300MPa - 33.67 min, D400MPa - 17.83 min and D500MPa - 16.03 min. The obtained results indicate that E. hirae is one of the most resistant vegetative bacteria to ultra high pressure treatment.     

C-reactive protein in monitoring and evaluation of effects of therapy of the MMA syndrome of sows

The elevated concentration of CRP in sows at the early stage of the MMA reflected the inflammation in the reproductive tract and in the mammary gland. Monitoring the level of CRP during the first days after parturition may be used to diagnose early stages of the MMA and to start therapy. In the treated MMA sows the level of CRP steadily decreased, and by the end of the experiment it had returned to the normal level. In the non-treated MMA sows CRP persisted at a high level and at day 10 of the experiment it was 13 times higher than in the treated animals and 16 times higher than in controls. Measurements of serum CRP are valuable in monitoring the health status of sows after parturition and should be introduced as the diagnostic method of the MMA syndrome in sows. The determination of the concentration of serum CRP during the first two days after parturition should be used for diagnosis of the early stages of MMA syndrome in sows and to start therapy when clinical symptoms of MMA are still absent.     

The effects of experimental infection with bovine diarrhoea virus (BVDV) on lymphocyte subpopulations in the peripheral blood of pigs

The aim of the study was to analyse the dynamics of selected lymphocytes subpopulations in peripheral blood of pigs infected with BVDV, using flow cytometric method. The examinations were performed on eighteen healthy, pestivirus-free pigs divided into 3 groups. Pigs in the group 1 were intranasally infected with two virulent reference strains of BVDV: NADL2 and NADL8. Pigs of group 2 were included into experimentally infected ones. Group 3 consisted of control pigs free from infection. The percentage of CD2+ lymphocytes was gradually decreasing during the experiment. Finally a decrease by 20% was noted in group 2 and by 9% in group 1. A slight decrease of CD4+ cells and more significant decrease of CD8+ subpopulation were observed. The CD4:CD8 ratio changed from approximately 3:5 to 1:1 in pigs of group 2, and from 1:2 to 1:3 in pigs of group 1. There were only small fluctuations regarding TcR(gamma)delta+ cells. The level of these lymphocytes increased during first hours post infection and then decreased to the initial value. Obtained results may indicate that infection with species-unspecific pestiviruses causes similar, but less significant, changes within lymphocyte subpopulations than infection with species-specific pestiviruses.     

Haemorheological Variables in a Rat Model of Hypertriglyceridaemic Obesity and Diabetes

Obesity is a heterogeneous condition of variable aetiology, generally associated with pathologies such as arterial hypertension, hyperlipidaemia, diabetes and cardiac disease. These conditions, either themselves or because of the various treatments used, may further modify blood rheology in an arbitrary manner. Therefore, analyses of changes in the blood rheology induced by obesity in humans have had differing and controversial results. In our laboratory, a model of hypertriglyceridaemic obesity is provided by an inbred rat strain; the genotype from the IIMb/Fm strain, presenting a syndrome of moderate obesity with apparent peripubertal onset, associated with hypertriglyceridaemia and glucose intolerance that turns into diabetes. The genotype, originated from the same IIM/Fm stock, represents the control.The present study describes a comparative analysis of the variables determining the rheological behaviour of the blood in obese and control strains. Our results, agreeing with some other studies performed in humans, confirmed the haemorheological changes associated with obesity, and the fact that these changes became more evident in the presence of pathologies such as diabetes. It appears that triglyceridaemia, cholesterolaemia and hyperglycaemia may influence the rheological behaviour of the cell membrane and this damage may provoke a decrease in erythrocyte deformability and, consequently, hyperviscosity of the blood.     

Characteristics and cholinergic control of the 'minute rhythm' in ovine antrum,small bowel and gallbladder

Eight adult conscious rams were used to characterize further the minute rhythm and to determine the role of cholinergic receptors in nervous control of this event. In chronic experiments, the myoelectrical and motor activity of the gastrointestinal tract and gallbladder were recorded. Physiological experiments were performed in fasted or non-fasted rams before, during and after feeding, and the occurrence of minute rhythm during various phases of the migrating motor myoelectric complex was observed. The pattern occurred most frequently in the small intestine, where it exhibited mostly the propagating character. It was also detectable in the ileum. In the gallbladder, the minute rhythm arrived systematically and its character was irregular, propagating, retropropagating or stationary. In all episodes observed, it was well correlated with that in the small intestine. In the pyloric antrum, the minute rhythm was identified occasionally. During pharmacological experiments, 0.15 M NaCl or graded doses of hexamethonium, atropine and pirenzepine were administered intravenously during various phases of the migrating motor myoelectric complex, in fasted and non-fasted animals, before and during feeding. The drugs inhibited the minute rhythm in the small bowel for a longer period than in the gallbladder. However, the smallest dose of pirenzepine (0.02 mg/kg) exerted a non-significant effect both in the small intestine and in the gallbladder. It is concluded, that in normal conditions the minute rhythm occurs regularly in the entire small intestine and in the gallbladder. In the small intestine the pattern is organized more precisely. The minute rhythm is controlled by nicotinic receptors and by muscarinic receptor subtypes.     

The influence of feeding and maintenance system on occurrence of Toxoplasma gondii infections in dogs

Serum samples of 113 dogs visiting "outpatient clinics", 52 dogs kept in shelters and 35 animals from a military dog training centre were examined for Toxoplasma gondii specific antibodies using a latex agglutination test. Significant differences in seroprevalences were found between dogs from the training centre (8.6% of positive results) and the other populations examined (40.7% of positive seroreagents in animals visiting outpatient clinics and 44.2% in the group from shelters, respectively). Among clinic patients, dogs fed raw meat were significantly more frequently seropositive (65.2%) than those eating only commercial dry feed or cooked meat (25.7%). No statistically significant differences were noted in males compared to females and in pure breed dogs compared to crossbreed dogs. The antibodies were usually found in low titres under 60 IU/ml (69.6% of positive results). High titres (120-480 IU/ml) were detected in 2 of 3 dogs with clinical toxoplasmosis. In these dogs IFAT T. gondii specific IgM were detected and a favourable response to antiprotozoal treatment was observed. All the dogs with medium and high titres were given raw meat. Age and the presence of cats did not seem to have any influence on T. gondii seroprevalence. Neospora caninum specific antibodies in low titres ranging from 1:20-1:320 were found in 7 (9.7%) of 72 T. gondii positive seroreagents.     

Antioxidant parameters of horses according to age,sex, breed and environment

Antioxidant defences interact to form an integrated system. There is no comprehensive and uniform view on issues concerning the antioxidant status in horses. Therefore, the aim of the present study was to estimate antioxidant parameters in horses of different age, sex and breed as well as environment and relationship between different antioxidants. Parameters of selected antioxidants including superoxide dismutase (SOD), glutathione peroxidase (GSH-px), total antioxidant status (TAS), ceruloplasmin (CP), bilirubin, uric acid, zinc, copper and selenium were determined in blood of 80 clinically healthy horses. Antioxidant parameters significantly varied between horses form different environments or different breed and sex. Age of horses had no significant effect on antioxidant parameters. Significant correlation coefficients were observed between enzymatic and nonenzimatic antioxidants. The nature of the relationship between the antioxidant system in horses with respect to environmental factors is rather complex and to date only a part of system is known.     

The patency of the utero-oviductal tract during the estrous cycle in the pig

The study of corrosion casts after filling the utero-oviductal lumen with heat-hardened resin Mercox, and scanning electron microscopy (SEM) observations of the tissue cross-sections were carried out in 63 pigs during the estrous cycle. Investigations of the corrosion casts showed that the barrier for the transportation through the utero-oviductal canal may occur in the oviductal isthmus, because this pathway was closed for Mercox resin between days 6-21 of the estrous cycle. SEM observations of the oviductal tissues confirmed that the smallest cross-sections of the porcine oviduct were found in the isthmus on 1-1.5 cm from the uterine horn, although with open lumen throughout the estrous cycle. However, in the intermediate parauterine part of the isthmus, with thick muscular layer (2850-3800 microns in a diameter) and with short strongly tighten apical mucous folds, main pathways for the transportation can be parabasal fissures, particularly on days 6-21 of the estrous cycle.     

Pharmacokinetics of tylosin in broiler chickens

Biological availability and pharmacokinetic properties of tylosin were determined in broiler chickens after oral (p.o.) and intravenous (i.v.) administration at a dose of 10 mg/kg. The calculated bioavailability--F%, by comparing AUC values--p.o. and AUC--i.v., ranged from 30%-34%. After intravenous injection tylosin was rapidly distributed in the organism, showing elimination half-life (t1/2 beta) values of 0.52 h and distribution volume (Vd) of 0.69 L/kg, at a clearance rate (Cl) of 5.30 +/- 0.59 ml/min/kg. After oral administration, tylosin has a similar distribution volume (Vd = 0.85 L/kg), while the elimination half-life t1/2 beta of 2.07 h was four times bigger than after i.v. administration at Cl = 4.40 +/- 0.27 ml/min/kg. The obtained value tmax = 1.5 h for tylosin after oral administration indicates that using this antibiotic with drinking water in broiler chickens is the method of choice. However, a relatively low value Cmax = 1.2 micrograms/ml after oral administration of tylosin shows that dosing of this antibiotic in broiler chickens should be higher than in other food producing animals.