Phaidra - University of Veterinary Medicine Vienna
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New insights into the N-glycomes of Dictyostelium species
No full textDictyostelia are cellular slime molds, a group of Amoebozoa, that form multicellular fruiting bodies out of aggregating cells able of differentiating into resistant spore forms. In previous studies on Dictyostelium discoideum, it was demonstrated that their N-glycans, as in most eukaryotes, derive from the Glc3Man9GlcNAc2-PP-Dol precursor; however, unique glyco-epitopes, including intersecting GlcNAc, core α1,3-fucosylation, sulphation and methylphosphorylation, were detected. In the present study, we have examined the N-glycans of two other Dictyostelium species, D. purpureum, whose genome is also sequenced, and D. giganteum. The detailed glycomic analysis of their fruiting bodies was based on isomeric separation of the glycan structures by HPLC, followed by mass spectrometry in combination with enzymatic digests and chemical treatments. Two features absent from the \u27model\u27 dictyostelid D. discoideum were found: especially in D. purpureum, a long linear galactose arm β1,4-linked to the β1,4-N-acetylglucosamine on the \u27lower\u27 A-branch of its oligo-mannosylated structures could be identified. In contrast, neutral N-glycans with multiple fucose residues attached to terminal mannoses were found in D. giganteum. All three species have common modifications on their anionic N-glycans: while (methyl)phosphorylated residues are always associated with terminal mannose residues, the sulphation position differs. While D. discoideum has 6-sulphation of subterminal mannose residues, D. giganteum and D. purpureum may rather have 2-sulphation of core α1,6-mannose. Overall, we have discovered species-specific glycan variations and our data will contribute to future comparative and functional studies on these three species within the same genus
Canine perspective taking: Anticipating the behavior of an unseen human
No full textAlthough dogs exhibit remarkable capabilities for interacting with humans, the underlying cognitive mechanisms remain insufficiently understood. Here, we investigated canine perspective taking by challenging dogs to decide whether and where to steal food in the absence of a human who had prohibited them from doing so. The dogs could only infer the experimenter\u27s presence through a sound (carrot chopping) they had perceived during a prior exploration phase, in which they also had the opportunity to observe from which locations in the room the human was visible. In the test, the majority of dogs preferred to steal from a plate that was not visible from the location where the human had chopped carrots before when they heard a playback of the chopping sound but not when they heard a control sound (street noise). These findings provide evidence that dogs anticipate the behavior of humans without relying on observable visual cues
Host-specific targets of Histomonas meleagridis antigens revealed by immunoprecipitation
No full textHistomonas meleagridis, a protozoan parasite responsible for histomonosis (syn. Blackhead disease, histomoniasis), presents an increasing challenge for poultry health, particularly with the ban of licensed prophylactic and treatment options. Recent studies have explored H. meleagridis proteome, exoproteome, and surfaceome, linking molecular data to virulence and in vitro attenuation. Nevertheless, proteins involved in interactions with hosts remain largely unknown. In this study, we conducted immunoproteome analyses to identify key antigens involved in the humoral immune response of the parasite\u27s main hosts, turkeys and chickens. Immunogenic proteins were isolated via immunoprecipitation using sera from chickens and turkeys that were vaccinated with a single attenuated strain and challenged with virulent strains of the protozoan, respectively. Mass spectrometry identified 155 putative H. meleagridis immunogenic proteins, of which 43 were recognized by sera from both hosts. In silico antigenicity screening (VaxElan) identified 33 pan-reactive antigens, with VaxiDL further highlighting 10 as potential vaccine candidates. Comparative analysis revealed host-specific immune responses, with 16 differential immunogenic proteins in chickens (6 specific to virulent and 10 to attenuated preparations) and 19 unique proteins in turkeys, all associated with virulent strains. These results enhance our understanding of H. meleagridis immunogenic protein dynamics and host-pathogen specificities, supporting the development of improved diagnostic tools and potential protective measures against the infection
Glycans of parasitic nematodes - from glycomes to novel diagnostic tools and vaccines
No full textNematodes, commonly known as roundworms, are among the most prevalent and diverse multicellular organisms on Earth, belonging to the large phylum Nematoda. In addition to free-living species, many nematodes are parasitic, infecting plants, animals, and humans. Nematodes possess a wide array of genes responsible for carbohydrate metabolism and glycosylation. The glycosylation processes in parasitic nematodes often result in unique glycan modifications that are not present in their hosts. These distinct glycans can be highly immunogenic to mammalian hosts and play significant immunoregulatory roles during infection. This mini-review article summarises the glycosylation capabilities and characteristics of parasitic nematodes based on glycomic data. It also highlights recent research advances that explore the biological significance of nematode glycans and their potential for diagnostic and vaccine applications
Short- and long-term changes in neurological, behavioural, and blood biomarkers following repeated mild traumatic brain injury in rats-potential biological sex-dependent effects
No full textChronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disease resulting from repeated mild traumatic brain injuries (rmTBI). The necessity for diagnosis of CTE, which can so far only be confirmed after post-mortem, is a pressing need. New approaches to early diagnose this disease are crucial to facilitate the translation of novel treatment strategies to the clinic. Several studies have found suitable candidate biomarkers, but the results are not straightforward. As biological sex is suggested to be a major confounding factor, we explored how sex influences behavioural and candidate blood biomarkers during CTE-like progression following experimental rmTBI.To induce CTE-like development, we subjected male and female rats to three mTBIs at a 5-day interval. We then monitored and analysed differences in neurological, behavioural, and physiological parameters up to 12?weeks after the injuries-both by sex and grouped-and underwent further analysis using generalised estimated equation (GEE). To determine long-term changes in tau aggregation as a hallmark of CTE, we used [18F]-florzolotau (florzolotau) autoradiography in brain slices.Both short-term weight gain and time-to-right after rmTBI were increased in grouped animals, with male rats showing more prominent changes. The neurological state was impaired after each mTBI and still 12?weeks later, independent of the sex. A protracted anhedonic-like behaviour due to rmTBI was found at the group level only at week 2 but remained continuously present in male rats. While spatial memory was not impaired, male rats showed increased anxiety-like behaviour. Moreover, neuron-specific enolase (NSE) was elevated in the blood 1?day after rmTBI, but only in females. On the contrary, blood p-tau was increased 3?days after rmTBI only in males. In addition, male rats showed significantly increased florzolotau binding in the brain after 12?weeks, suggesting brain contusion causes increased tau aggregation. Interestingly, brain neurofibrillary tangles (NFTs) at 12?weeks after rmTBI showed a strong correlation with the neurological state at 1?day after rmTBI.Taken together, our findings suggest that male rats may be more susceptible to short-and long-term consequences of rmTBI in the applied model. These sex differences should be considered when translating preclinical biomarker candidates to the clinic. Understanding these differences could guide the diagnosis and treatment of CTE in a personalized manner, offering hope for more effective treatments in the future
Watched or not: Overimitation in dogs under different attentional states
No full textDomestic dogs (Canis familiaris) have been documented to \u27overimitate\u27 humans - a form of social learning - by copying their causally-irrelevant actions. It is suggested that this behaviour results from social, affiliative motivations. Dogs have also been known to behave differently when they are being watched (or not) by humans, such as by following commands better (or worse). In this study, we tested whether dogs\u27 copying behaviour would also be sensitive to their caregiver\u27s attentional states. The subject\u27s caregiver demonstrated irrelevant and relevant actions in the dot-touching overimitation task, then during trials the caregiver was either watching their dog or turned away. Our results revealed no difference in dogs\u27 irrelevant-action copying; however, we found that dogs approached the dots less per trial when their caregiver was watching them. Dogs also copied their caregiver\u27s leftward sliding of a door (to obtain a food reward) more accurately when they were being watched by their caregiver. Finally, dogs who copied the irrelevant action did so more often after obtaining their food reward, which supports that these dogs may have had two separate goals: a primary instrumental goal and a secondary social goal
From Livestock to Companion: Admission Causes, Diagnostics, and Clinical Findings in Chickens Admitted to the Avian Clinic of the Vetmeduni Vienna, 2009-2019
No full textThis retrospective study investigated the clinical presentation, diagnostic findings, and treatment outcomes in 419 backyard (pet) chickens admitted to the Service for Avian and Reptiles at the University of Veterinary Medicine Vienna from 1 May 2009 to 30 April 2019. The median age of the chickens was 1.5 years, with 83.8% being female. The majority (80.0%) presented with individual clinical issues, while 20.0% were diagnosed with flock diseases. The most common admission causes included unspecific clinical signs (57.3%), respiratory tract issues (18.4%), and locomotor problems (16.2%). Diagnostic imaging modalities such as ultrasonography, radiography, and CT scans revealed pathologies, including ascites, salpingitis, and skeletal system abnormalities. Parasitological examinations found a high rate of coccidia, Capillaria, and Ascaridia, while microbiological analysis identified Escherichia coli and Pasteurella multocida as common bacterial pathogens. The most prevalent diseases were upper respiratory tract infections (13.8%), egg peritonitis (9.9%), and soft tissue trauma (9.4%). Treatment outcomes showed that 67.5% survived to discharge, while 32.2% died or were euthanized. Surgical interventions were performed in 25.3% of cases, with the most common surgeries being salpingohysterectomy and wound debridement. This study highlights the wide range of health issues faced by pet chickens and emphasizes the importance of accurate diagnosis and targeted treatment in avian veterinary care. It also underscores the role of various diagnostic tools, such as imaging, pathogen detection, and histopathology, in addressing the health challenges of backyard chickens
Comparing overimitation between assistance dogs and family dogs at home
No full textOver the past few years, the copying of irrelevant actions (overimitation) has been studied in domestic dogs, with evidence supporting the hypothesis that the dog-human relationship drives this behaviour. To further explore this influence, we compared two distinct groups of dogs with potentially differing relationship qualities to their caregivers in an overimitation (OI) task: assistance dogs and family dogs. Using the Monash Dog Owner Relationship Scale (MDORS), we assessed caregiver perceptions of the dog-human bond and found significant differences between these two groups. Unlike previous studies conducted in laboratory settings, we studied overimitation in a naturalistic home environment to better understand its occurrence in everyday life. Surprisingly, our findings revealed that assistance dogs did not copy their caregiver’s irrelevant actions significantly more than family dogs, but family dogs performed the irrelevant actions significantly more than a group without any action-demonstrator. Interestingly, only 34.7 % of all dogs in our sample overimitated, highlighting variability in this behaviour across individuals. However, our results suggest that overimitation also occurs within family dogs’ day-to-day environment, but assistance dogs with special training do not show higher OI rates in comparison
Encapsidic production and isolation of degradation-prone polypeptides
No full textDegradation during production and delivery is a significant bottleneck in developing biomolecular therapies. Protein cages, formed by engineered variants of lumazine synthase, present an effective strategy for the microbial production and isolation of labile biomolecular therapies. Genetic fusion of the target polypeptide to a cage component protomer ensures its efficient encapsulation within the cage during production in host bacterial cells, thereby protecting it from degradation. Furthermore, controlled cage opening outside the cellular environment facilitates the isolation of the encapsulated cargo through sequence-specific protease cleavage. Notably, the system features a modular patchwork assembly to prevent guest overloading, avoiding unwanted incomplete cage formation and insoluble aggregates. The broad applicability of the “encapsidic” approach is demonstrated by the efficient production of six distinct, intrinsically disordered polypeptides with proven therapeutic potential
Box-Cox-transformation for various classes of (generalized) linear (mixed effects) models : Version 1.1 (2025-12)
No full textVersion 1.1 der Funktion boxcox.ac() für R, die über einen definierten Bereich an Lambda-Werten, in Abhängigkeit der Daten, entweder bcPower- oder yiPower-Transformationen der abhängigen Variable in unterschiedlichen Klassen von linearen Modellen durchführt (einschließlich generalisierter und gemischter linearer Modelle der Klassen lm, glm, gls, lme, lmerMod, glmerMod und negbin), den optimalen Lambda-Wert identifiziert und die mit diesem Wert transformierte anhängige Variable des Modells ausgibt.
Die neue Version enthalt einen Bugfix (der Fehler trat auf wenn die Vorgängerversion auf lme4-Modelle angewandt wurde) sowie die Implementierung von glmmTMB-Modellen.Version 1.1 of the boxcox.ac() function for R that performs, depending on the data, either bcPower- or yiPower-transformations of the dependent variable over a set range of lambda values in various classes of linear models (i.e., including generalized and mixed effects models of the classes lm, glm, gls, lme, lmerMod, glmerMod, glmmTMB, and negbin), identifies the optimal lambda value for transformation and returns the accordingly transformed dependent variable.
This version includes a bugfix (the bug occured when applying the previous version to lme4-models) and now also implements glmmTMB models