COMPARATIVE EVALUATION OF HYDROPIC DEGENERATION OF THE LIVER IN DAIRY CATTLE THROUGH BIOCHEMISTRY, ULTRASONOGRAPHY AND DIGITAL ANALYSIS

Ultrasonography of the liver of 181 Holstein-Friesian cows was performed and blood samples were collected for analysis. The hepatic ultrasonograms were evaluated and the echoes were analyzed digitally. After slaughter, liver specimens were taken and examined histopathologically. Of the 181 animals, 120 had a normal liver and 61 had hydropic degeneration of the liver, diagnosed through histopathologic examination. Diagnostic accuracy rates for hydropic degeneration were determined based on the following test positive conditions: a) for biochemical analysis—high levels of aspartate aminotransferase, alanine aminotransferase, total bilirubin and non-esterified fatty acids; b) for ultrasonography—presence of dark pattern and blurring of edges; and c) for digital analysis—low echo means at 1 cm and 3 cm from the hepatic surface. Digital analysis had the highest overall specificity, accuracy and positive predictive values for hydropic degeneration, followed by ultrasonography. The results suggest that ultrasonography and digital analysis of hepatic ultrasonograms can be used for diagnosis of hydropic degeneration of the liver in place of biochemical analysis.     

MAGNETIC RESONANCE IMAGING OF CEREBRAL CORTICAL NECROSIS (POLIOENCEPHALOMALACIA) IN A DOG

A 3-year-old neutered female mixed breed dog was examined because of severe, generalized seizure activity, tetraparesis, and encephalopathic signs. Cerebrospinal fluid (CSF) evaluation was unremarkable except for a mild increase in protein. Serum and CSF titers for infectious diseases were negative. Magnetic resonance (MR) imaging examination of the brain was performed and lesions were found within the cerebral gray matter of the temporal and parietal lobes. The lesions had increased signal intensity on T1, T2, and proton density-weighted images. There was mild inhomogeneous enhancement following intravenous contrast medium administration. Neurologic status improved and the seizures were well controlled, but the dog never regained normal mentation and euthanasia was performed 10 weeks after initial evaluation. At necropsy, severe cerebral cortical necrosis was found in the regions corresponding to the lesions seen on MR imaging examination. Large numbers of fat-containing macrophages (gitter cells) were found within these areas, and are thought to be responsible for the characteristic hyperintensity seen on the MR images.     

The effect of volatile anaesthetics on the relative sensitivity of facial and distal thoracic limb muscles to vecuronium in dogs

ObjectiveTo compare n. facialis-m. nasolabialis (nF-mNL) and n. ulnar-mm. carpi flexorii (nU-mCF) sensitivity to vecuronium during halothane or isoflurane anaesthesia.Study designRandomized, prospective, experimental study.AnimalsForty-four client-owned dogs (19 male, 25 female) undergoing surgery; mean age: 5.0 years; mean body mass: 24.7 kg.MethodsThirty minutes after acepromazine (0.05 mg kg^?1) and morphine (0.5 mg kg^?1), anaesthesia was induced with intravenous (IV) thiopental and maintained with either halothane (n = 22) or isoflurane (randomly allocated) in oxygen. The lungs were mechanically ventilated and end-tidal inhaled anaesthetic (Fe’_IAA) maintained at 1.2 × MAC values. Neuromuscular transmission at nF-uNL and nU-mCF was monitored using the train of four count. Vecuronium (50 μg kg^?1 IV) was injected (t = 0) after 15 trains, 50-60 minutes after inhalational anaesthesia began, when Fe’_IAA had been constant for >15 minutes. Times of the disappearance (-) and reappearance (+) of the fourth (T4) and first twitch (T1) were recorded allowing the calculation of: latent (t = 0 to T4-) and manifest onset times (t = 0 to T1-) duration of blockade (T1- to T1+) and drug effect (T4- to T4+) and recovery time (T1+-T4+). Student’s paired t-test was used to compare simultaneous responses at nF-uNL and nU-mCF. An unpaired t-test was used to compare anaesthetic effects.ResultsLatent and manifest onset times were significantly (p < 0.05) briefer, blockade and drug effects were significantly longer and recovery from blockade were significantly slower in the nF-mNL unit in both halothane and isoflurane recipients. Profound block duration and drug action were significantly longer and recovery from blockade were significantly slower in halothane recipients at both nerve-muscle units.Conclusion and clinical relevanceThe nF-mNL was more sensitive than nU-mCF to vecuronium, particularly in halothane-anaesthetized dogs.     

Genetic immunization with the immunodominant antigen P48 of Mycoplasma agalactiae stimulates a mixed adaptive immune response in BALBc mice

A DNA vaccine against contagious agalactia was developed for the first time, encoding the P48 of Mycoplasma agalactiae. Specific immune responses elicited in BALB/c mice were evaluated. Both total IgG and IgG1 were detected in mice vaccinated with pVAX1/P48. Proliferation of mononuclear cells of the spleen, levels of gamma interferon, interleukin-12, and interleukin-2 mRNAs were enhanced in immunized animals. Results indicate that pVAX1/P48 vaccination induced both T_h1 and T_h2 immune responses. Nucleic acid immunization could be a new strategy against M. agalactiae infections and may be potentially used to develop vaccines for other Mycoplasma diseases.     

Interleukins: Biological Properties and Therapeutic Potential

Interleukins are biologically active glycoproteins derived primarily from activated lymphocytes and macrophages. Tremendous insight into the biochemical and biological properties of interleukins has been gained with advances in recombinant DNA technology, protein purification, and cell-culture techniques. The biological properties of interleukins include induction of T-lymphocyte activation and proliferation, augmentation of neutrophil, macrophage, and T-lymphocyte cytotoxicity, and promotion of B lymphocyte and multilineage bone marrow stem-cell precursor growth and differentiation. Interleukins may play a role in the pathogenesis of several important diseases. Interleukin therapy is likely to play an important role in the treatment of cancer, infectious diseases, and immunodeficiency syndromes.     

Salmonella enterica serovar Choleraesuis derivatives harbouring deletions in rpoS and phoP regulatory genes are attenuated in pigs, and survive and multiply in porcine intestinal macrophages and fibroblasts, respectively

Live attenuated Salmonella enterica strains have been extensively studied as potential vectors for the oral delivery of heterologous antigens. Due to its ability to target immune cells, its specific mechanism for crossing the intestinal barrier, and its swine-restricted tropism, S. enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) has attracted a great deal of interest for the production of bacterial-based oral carriers specifically adapted to swine. In this study, two mutants of S. Choleraesuis were constructed and their attenuation and intracellular fate analysed with the purpose of engineering new attenuated live strains with improved properties as oral vaccine carriers. Those strains harboured a specific deletion either within the phoP or rpoS genes, which encode virulence-related regulators in S. Typhimurium. In comparison to the wild-type parental S. Choleraesuis, the mutant strains, especially DeltaphoP, were extremely low in virulence in the murine model and in the natural host, the pig. Moreover, when compared with a commercial live vaccine strain, SC-54, the two mutants showed a higher level of attenuation in mice and DeltaphoP also in pigs. In addition, DeltarpoS and DeltaphoP presented a proliferation and survival phenotype within swine intestinal primary fibroblast and macrophage cell cultures, respectively. Collectively, the present results indicate that the DeltarpoS and DeltaphoP strains of S. Choleraesuis gather adequate features to be potential candidates for vaccine vectors for the specific delivery of heterologous antigens adapted to pigs.