Development of Deep and Upper Neuronal Layers in the Domestic Cat,Sheep and Pig Neocortex

The neocortex plays a key role in cognition, volitional motor control and sensory perception and has undergone tremendous expansion during evolution. The mature neocortex consists of radially aligned neurons that are arranged in six layers. Layers II–VI are often split into two groups: deep and upper layers, both building up the so‐called cortical plate during embryonic and foetal development. So far cortical neurogenesis, including the generation of deep and upper layers, has mostly been studied in laboratory rodents and primates. However, precise data for most companion animals are lacking. This study determined the main period of neurogenesis, specifically the timing of deep and upper layer generation, in the developing domestic cat, pig and sheep neocortex using immunohistochemistry for specific neuronal markers, that is Tbr1 and Brn2. We found that the general sequence of neural events is preserved among cat, pig, sheep and other mammalian species. However, we observed differences in the timing of the overall cortical neurogenic period and occurrence of distinct neural events when these three species were compared. Moreover, our data provide further evidence that the cortical neurogenic period and gestation length might be tightly related. Together, these data expand our current understanding of neocortex development and are important for future studies investigating neocortex development and expansion especially in companion animals.     

Effect of the recently established admissions procedure on success in the first-year exams at the University of Veterinary Medicine Vienna, Austria

RATIONALE FOR THIS STUDY: The purpose of this study was to compare the success during the first academic year of students who underwent an admissions procedure (class 2005) and students of the three previous classes (2002-2004), who did not undergo an admissions procedure but took their exams under the same curricular framework. METHODOLOGY: Exam results of 802 students of the 2002-2004 classes were compared with those of 181 students from the 2005 class. RESULTS: Students of the 2005 class were more likely to pass all three exams given in the first academic year than students of the 2002-2004 classes (p < 0.001; OR = 3.2), and the quality of two of the three exams (indicated by individual scores) was also significantly better in 2005 than in the preceding classes (p < 0.001). In unselected classes, 25% to 31% of students showed no successful attempts to pass any of the three exams currently administered. CONCLUSION: The implementation of an admissions procedure measuring, among other indicators, academic ability has significantly improved first-year exam performance. Incoming students presenting with higher scores on academic standards are more likely to complete their courses successfully.     

Comparative efficacies of oral ketoconazole and terbinafine for reducing Malassezia population sizes on the skin of Basset Hounds

The objective of this study was to compare the efficacy of oral ketoconazole and terbinafine for reducing population sizes of Malassezia yeasts on canine skin. Twenty-one Basset Hounds were randomised in three groups of seven according to Malassezia populations. Dogs in the first group were treated by oral administration of ketoconazole (Ketofungol) 200 mg, Janssen-Cilag) at 10 mg x kg-1, every 24 h with food, for 3 weeks. Dogs in the second group were treated by oral administration of terbinafine (Lamisil) 250 mg, Novartis) at 30 mg x kg-1, every 24 h with food, for 3 weeks. The seven remaining dogs were used as controls. Malassezia population sizes were assessed by use of contact plates on four cutaneous sites at days 7, 14 and 21. Both ketoconazole and terbinafine were effective in reducing the baseline levels of Malassezia organisms with no significant difference between the two drugs. In further studies, oral terbinafine should be evaluated for the management of canine cases of Malassezia dermatitis.     

Immunization of chickens with Salmonella enterica subspecies enterica serovar Enteritidis pathogenicity island-2 proteins

Several structural components of the type III secretion systems (T3SS) encoded by Salmonella pathogenicity island (SPI)-1 and SPI-2 are exposed to the host's immune system prior to/during the infection/invasion process, making them potential vaccine candidates. In this study we evaluated whether chickens vaccinated with SPI-2 T3SS components could mount a significant humoral immune response (as measured by serum IgG titres) and whether these antibodies could be transferred to progeny (as measured by egg yolk IgG titres), and whether vaccinates and progeny of vaccinates could be protected against challenge with SE. The results of our studies show that vaccinated chickens do produce high levels of SPI-2 T3SS specific serum IgG that they are able to transfer to their progeny. It was demonstrated that vaccinates and progeny of vaccinates had lower overall countable recovered Salmonella enterica subspecies enterica serovar Enteritidis (SE) per bird in most situations.     

Antimicrobial susceptibility testing of German Campylobacter fetus subsp. venerealis isolates by agar disk diffusion method

Campylobacter fetus subsp. venerealis is the causative agent of bovine genital campylobacteriosis and is transmitted by asymptomatic carrier bulls via contaminated semen during artificial insemination. The aim of the present study was to determine the in vitro susceptibility of Campylobacter fetus subsp. venerealis isolated from bovine specimens in the years from 2000 to 2009 in Germany to antibiotics generally used in semen treatment. The susceptibilities of 50 strains to spectinomycin (10 microg), gentamicin (10 microg), streptomycin (25 microg), penicillin (10 microg), lincomycin (10 microg), ciprofloxacin (5 microg), erythromycin (30 microg) and tetracycline (30 microg) were determined using a disk diffusion susceptibility test. All strains were susceptible to gentamicin. A considerably reduced susceptibility to one or more antimicrobial agents was detected in seven out of 50 isolates (14%) with the most frequent reduction in susceptibility to lincomycin and spectinomycin. Furthermore, strains with reduced susceptibility to more than one antimicrobial agent were always associated with reduced susceptibility to lincomycin. It is recommended to determine the antimicrobial susceptibility of Campylobacter fetus subsp. venerealis isolates in order to evaluate the efficacy of the generally used antibiotic treatment of bull semen and to detect possible resistances.     

Demonstration of the articular cartilage of the canine ulnar trochlear notch using high-field magnetic resonance imaging

The articular cartilage covering the ulnar trochlear notch (UTN) of both elbow joints from 25 adult canine cadavers was demonstrated by the use of high-field magnetic resonance imaging (MRI) with a fat-suppressed, three-dimensional, spoiled gradient echo sequence. The dogs used for this study were divided into five groups: giant, large, mid-sized, small, and chondrodystrophic breeds. The distribution of articular cartilage of the UTN was assessed on MR images. The joints were then opened, and the distribution of the articular cartilage of the UTN was verified. In 29/50 joints, there was good agreement between gross findings of the distribution of the articular cartilage of the UTN and MRI interpretation. Reasons for the poor results in small and chondrodystrophic breeds were decreased thickness of the articular cartilage, small size of the articular surface and of its structural features, and the frequent inability to visualize the joint space.     

Clinical trial evaluating the efficacy and safety of cyclosporine in dogs with atopic dermatitis

OBJECTIVE: To determine efficacy and safety of cyclosporine in the treatment of atopic dermatitis among dogs in North America. DESIGN: Randomized controlled (phase 1) and open-label (phase 2) trials. ANIMALS: 268 dogs with atopic dermatitis. PROCEDURE: In phase 1, dogs were randomly assigned to be treated with cyclosporine (5 mg/kg [2.3 mg/Ib], PO, q 24 h) or a placebo. In phase 2, all dogs were treated with cyclosporine for 16 weeks. Frequency of cyclosporine administration was decreased if dogs improved clinically. RESULTS: At the end of phase 1, canine atopic dermatitis extent and severity index (CADESI) scores for dogs treated with cyclosporine were significantly lower than scores for control dogs. Percentage of dogs with severe pruritus decreased from 67% to 16% for the cyclosporine group but from 66% to only 61% for the control group. During phase 2, cyclosporine dosage was decreased to every-other-day administration in 39% of the dogs after 4 weeks. After 12 weeks, 22% of the dogs were treated twice weekly and 36% were treated every other day. After 16 weeks, CADESI score had decreased > 50% in 68% of the dogs and 47% of dogs had no or mild pruritus. The most frequent adverse reactions were gastrointestinal tract signs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cyclosporine is efficacious for the treatment of atopic dermatitis in dogs and that frequency of cyclosporine administration can be reduced following an initial induction period. The drug was well tolerated.     

Plasma levels of a low-dose constant-rate-infusion of ketamine and its effect on single and repeated nociceptive stimuli in conscious dogs

This study quantitatively investigated the analgesic action of a low-dose constant-rate-infusion (CRI) of racemic ketamine (as a 0.5 mg kg⁻¹ bolus and at a dose rate of 10 μg kg⁻¹ min⁻¹) in conscious dogs using a nociceptive withdrawal reflex (NWR) and with enantioselective measurement of plasma levels of ketamine and norketamine. Withdrawal reflexes evoked by transcutaneous single and repeated electrical stimulation (10 pulses, 5 Hz) of the digital plantar nerve were recorded from the biceps femoris muscle using surface electromyography.Ketamine did not affect NWR thresholds or the recruitment curves after a single nociceptive stimulation. Temporal summation (as evaluated by repeated stimuli) and the evoked behavioural response scores were however reduced compared to baseline demonstrating the antinociceptive activity of ketamine correlated with the peak plasma concentrations. Thereafter the plasma levels at pseudo-steady-state did not modulate temporal summation. Based on these experimental findings low-dose ketamine CRI cannot be recommended for use as a sole analgesic in the dog.     

Seizure activity in dogs is associated with enhanced TIMP-2 expression of microglia

In the pathogenesis of epilepsy aberrant synaptic plasticity plays an important role. Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are responsible for nervous tissue remodelling resulting in synaptic plasticity in the central nervous system (CNS) and might therefore be crucially involved in epileptogenesis. To assess the potential pathogenetic role of microglial MMPs and TIMPs in seizure induction, twenty-four dogs suffering from different intracranial diseases with and without seizure activity were comparatively examined. Microglial cells were isolated by density gradient centrifugation and their expression profiles of MMP-2, MMP-9, MMP-12, MMP-13, MMP-14, TIMP-1, TIMP-2, and RECK (reversion-inducing cysteine-rich protein with Kazal motifs) were examined via quantitative real-time PCR (qPCR). Interestingly, a significant up-regulation of TIMP-2 expression was found for the first time in dogs suffering from seizures. In conclusion, microglial TIMP expression might be involved in seizure generation.