Tiermedizin in Berlin

Oktober 201

Comparative Pathology of Pseudorabies in Different Naturally and Experimentally Infected Species—A Review

The pseudorabies virus (PRV) is an alphaherpesvirus and the causative agent of Aujeszky’s disease (AD). PRV infects a wide range of animal species including swine as the natural host as well as ruminants, carnivores, rodents and lagomorphs. In these species, except for the pig, PRV infection causes acute, severe disease, characterized by insatiable itching, and is always lethal. Horses, chickens and non-human primates have been shown to be largely resistant to PRV infection, while disease in humans is still controversial. PRV is a pantropic virus, which preferably invades neural tissue, but also infects epithelia of various organs, whereupon multisystemic lesions may result. Although AD is mainly associated with severe pruritus, also known as “mad itch”, there are notable differences regarding infection route, clinical signs, viral distribution and lesion patterns in different animal species. In this comprehensive review, we will present clinico-pathologic findings from different species, which have been either shown to be susceptible to PRV infection or have been tested experimentally

Ischaemic paraspinal myopathy along with myelopathy due to putative fibrocartilaginous embolism in a dog

A 10-year-old German shepherd dog was presented with peracute onset of non-ambulatory paraparesis. Clinical signs and neurological examination revealed lack of proprioception and reduced to absent reflexes in both hind limbs, indicating a lesion to spinal cord segments (SCS) L4–S3. In contrast, MRI identified intramedullary signal changes within the SCS T13–L2 and a sharply demarcated zone of signal changes in the adjacent dorsal lumbar musculature on the left side. The findings were consistent with ischaemic myelopathy, most likely due to fibrocartilaginous embolism (FCE). The lesion also included large areas of presumably ischaemic myopathy which was confirmed by histopathology of biopsies from adjacent muscles. On re-examination, three months after presentation, ambulatory paraparesis remained, proprioceptive deficits improved and spinal reflexes were normal. However, the affected left longissimus lumborum muscle had become markedly atrophic. FCE as the most common cause for ischaemic myelopathy obviously may also induce ischaemic paraspinal myopathy

Pathology of African Swine Fever in Wild Boar Carcasses Naturally Infected with German Virus Variants

In 2020, African swine fever (ASF) was first identified in German wild boar, reaching a case number of about 4400 to date. Upon experimental infection, pathology is well documented; however, data on field infections are scarce in domestic pigs and not available from wild boar, respectively. Although the ASF viral genome is considered exceptionally stable, a total of five lineages with 10 distinct virus variants of genotype II have emerged in Eastern Germany. To investigate the pathology in naturally infected wild boar and to evaluate virus variants II, III and IV for their virulence, wild boar carcasses were obtained from three different outbreak areas. The carcasses underwent virological and pathomorphological investigation. The animals revealed characteristic ASF lesions of the highest severity accompanied by bacterial infections in several cases. In particular, wild boar infected with variant IV from Spree-Neiße (SN) district showed lower viral genome loads and total viral antigen scores, but simultaneously tended to reveal more chronic lesions. Our findings indicate a protracted course of the disease at least after infection with variant IV, but need confirmation under standardized experimental conditions. There is a strong need to monitor differences in the virulence among variants to identify potential attenuation that might complicate diagnosis. In addition, veterinarians, hunters and farmers need to be made aware of less acute courses of ASF to consider this as an important differential to chronic classical swine fever

VivoTrax+ improves the detection of cancer cells with magnetic particle imaging

Cellular imaging is a rapidly growing field as novel tracers and imaging techniques are developed. Magnetic particle imaging (MPI) detects superparamagnetic iron oxide nanoparticles (SPIO), which can be used to label cells. The unique detection of SPIO-labeled cells boasts MPI as a sensitive modality; as such, the type of SPIO has a critical role in determining sensitivity and resolution. For cell tracking applications, the ideal SPIO should label cells efficiently and retain its sensitivity after cellular uptake. VivoTraxTM, a commercially available and commonly used SPIO for MPI, was recently re-released as VivoTrax+TM with an improved size distribution enriched for larger particles. In this study, VivoTrax+TM is shown to enhance cellular labeling and improve in vitro/in vivo sensitivity. Importantly, the sensitivity of both SPIO significantly decreased after cellular internalization. The results from this study emphasize the importance of translating SPIO performance in vivo to maintain its utility for cell tracking applications

VivoTrax+ improves the detection of cancer cells with magnetic particle imaging

Cellular imaging is a rapidly growing field as novel tracers and imaging techniques are developed. Magnetic particle imaging (MPI) detects superparamagnetic iron oxide (SPIO) particles, which can be used to label cells., The type of SPIO has a critical role in determining MPI sensitivity and resolution. For cell tracking applications, the ideal SPIO should label cells efficiently and retain its sensitivity after cellular uptake. VivoTraxTM, a commercially available and commonly used SPIO for MPI, was recently re-released as VivoTrax+ with an improved size distribution enriched for larger particles. In this study, VivoTrax+ is shown to enhance cellular labeling and improve in vitro/in vivo sensitivity. Importantly, the sensitivity of both SPIO significantly decreased after cellular internalization. The results from this study emphasize the importance of translating SPIO performance in vivo to maintain its utility for cell tracking applications.   Int. J. Mag. Part. Imag. 8(2), 2022, Article ID: 2210001, DOI: 10.18416/IJMPI.2022.221000

An improved animal model for herpesvirus encephalitis in humans.

Herpesviral encephalitis caused by Herpes Simplex Virus 1 (HSV-1) is one of the most devastating diseases in humans. Patients present with fever, mental status changes or seizures and when untreated, sequelae can be fatal. Herpes Simplex Encephalitis (HSE) is characterized by mainly unilateral necrotizing inflammation effacing the frontal and mesiotemporal lobes with rare involvement of the brainstem. HSV-1 is hypothesized to invade the CNS via the trigeminal or olfactory nerve, but viral tropism and the exact route of infection remain unclear. Several mouse models for HSE have been developed, but they mimic natural infection only inadequately. The porcine alphaherpesvirus Pseudorabies virus (PrV) is closely related to HSV-1 and Varicella Zoster Virus (VZV). While pigs can control productive infection, it is lethal in other susceptible animals associated with severe pruritus leading to automutilation. Here, we describe the first mutant PrV establishing productive infection in mice that the animals are able to control. After intranasal inoculation with a PrV mutant lacking tegument protein pUL21 and pUS3 kinase activity (PrV-ΔUL21/US3Δkin), nearly all mice survived despite extensive infection of the central nervous system. Neuroinvasion mainly occurred along the trigeminal pathway. Whereas trigeminal first and second order neurons and autonomic ganglia were positive early after intranasal infection, PrV-specific antigen was mainly detectable in the frontal, mesiotemporal and parietal lobes at later times, accompanied by a long lasting lymphohistiocytic meningoencephalitis. Despite this extensive infection, mice showed only mild to moderate clinical signs, developed alopecic skin lesions, or remained asymptomatic. Interestingly, most mice exhibited abnormalities in behavior and activity levels including slow movements, akinesia and stargazing. In summary, clinical signs, distribution of viral antigen and inflammatory pattern show striking analogies to human encephalitis caused by HSV-1 or VZV not observed in other animal models of disease