Phaidra - University of Veterinary Medicine Vienna
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Evaluation of spermatogenesis in stallions after GnRH immunization and re-stimulation of the testicular function with a GnRH agonist
No full textDiploma thesis - University of Veterinary Medicine Vienna - 2024Context: Stallions can exhibit aggressive tendencies, which can negatively impact their performance during training and competition. Such behavior also poses challenges for daily management. To avoid surgical castration, alternative methods to suppress reproductive behavior, such as GnRH vaccinations, can be used.
Aims: This study evaluated histological changes in spermatogenesis and seminiferous tubule size in stallions following successive GnRH vaccination and stimulation of testicular function with GnRH agonist.
Methods: Twelve fertile Shetland stallions were included. Stallions of the experimental group (n=6) were vaccinated against GnRH (Improvac 400 μg twice, four weeks apart, weeks 0 and 4) and stallions in the control group (n=6) received 1 mL of saline. When testosterone levels dropped below 0,3 ng/mL for two consecutive weeks, hemicastration was performed. The removed testicles were conserved for histology. Three weeks after hemicastration, the treatment with the GnRH agonist buserelin (4 μg /day for 4 weeks followed by 8 μg/day until castration) was initiated. The remaining testicles were removed when blood testosterone concentration exceeded 0,5 ng/mL for two consecutive weeks. Testicular tissues were again conserved for histology. Fifteen seminiferous tubules per stallion for each hemicastration were examined to evaluate spermatogenesis.
Key results: GnRH vaccination led to a decrease in Johnsen score, area, and perimeter in seminiferous tubules. This implicates a disruption of spermatogenesis. However, after the second hemicastration, these parameters returned to pre-vaccination levels. Buserelin treatment effectively restored the spermatogenesis.
Conclusion: GnRH vaccination affects spermatogenesis in stallions. The Johnsen score parameter, the area and perimeter of the seminiferous tubules can be restored using a GnRH agonist. The study observed variations in the extent of spermatogenesis disruption based on age. Further data needs to be collected to get further insight into the level of spermatogenesis disruption on age.
Implications: Daily administration of buserelin may be advisable for GnRH-vaccinated stallions to recover spermatogenesis.Diploma thesis - University of Veterinary Medicine Vienna - 2024Context: Stallions can exhibit aggressive tendencies, which can negatively impact their performance during training and competition. Such behavior also poses challenges for daily management. To avoid surgical castration, alternative methods to suppress reproductive behavior, such as GnRH vaccinations, can be used.
Aims: This study evaluated histological changes in spermatogenesis and seminiferous tubule size in stallions following successive GnRH vaccination and stimulation of testicular function with GnRH agonist.
Methods: Twelve fertile Shetland stallions were included. Stallions of the experimental group (n=6) were vaccinated against GnRH (Improvac 400 μg twice, four weeks apart, weeks 0 and 4) and stallions in the control group (n=6) received 1 mL of saline. When testosterone levels dropped below 0,3 ng/mL for two consecutive weeks, hemicastration was performed. The removed testicles were conserved for histology. Three weeks after hemicastration, the treatment with the GnRH agonist buserelin (4 μg /day for 4 weeks followed by 8 μg/day until castration) was initiated. The remaining testicles were removed when blood testosterone concentration exceeded 0,5 ng/mL for two consecutive weeks. Testicular tissues were again conserved for histology. Fifteen seminiferous tubules per stallion for each hemicastration were examined to evaluate spermatogenesis.
Key results: GnRH vaccination led to a decrease in Johnsen score, area, and perimeter in seminiferous tubules. This implicates a disruption of spermatogenesis. However, after the second hemicastration, these parameters returned to pre-vaccination levels. Buserelin treatment effectively restored the spermatogenesis.
Conclusion: GnRH vaccination affects spermatogenesis in stallions. The Johnsen score parameter, the area and perimeter of the seminiferous tubules can be restored using a GnRH agonist. The study observed variations in the extent of spermatogenesis disruption based on age. Further data needs to be collected to get further insight into the level of spermatogenesis disruption on age.
Implications: Daily administration of buserelin may be advisable for GnRH-vaccinated stallions to recover spermatogenesis.Diplomarbeit - Veterinärmedizinische Universität Wien - 202
Correlation between immunoglobulin concentration and somatic cell count in bovine colostrum
No full textDiplomarbeit - Veterinärmedizinische Universität Wien - 2024Die vorliegende Arbeit beschäftigte sich mit dem Thema der Kolostrum Qualität in Bezug auf Immunglobulingehalt und somatischer Zellzahl (SCC). Der Fokus lag auf der SCC in der Milch ante und post-partum sowie jene im Kolostrum. Es wurden 947 Kolostrumproben von 72 Betrieben unterschiedlicher Größen im österreichischen Bundesland Salzburg gesammelt. Von diesen 72 Betrieben waren 47 Mitglieder des Landeskontrollverbands Salzburg (LKV). In Zusammenarbeit mit dem Tiergesundheitsdienst Salzburg (TGD) wurden die Daten der 47 LKV-Betriebe anonymisiert übermittelt und konnten so zur weiteren Datenverarbeitung herangezogen werden. Zu der Bestimmung der SCC der 1.051 Kolostrumproben wurde ein mobiles Zellzahlmessgerät (DeLaval cellcounter DCCⓇ, DeLaval, Schweden) eingesetzt, welches auf dem Prinzip der optischen Fluoreszenz beruht. Durch vergleichende und deskriptive Statistik wurden die entsprechenden Resultate der Proben mit der Datenbank des LKVs verglichen. Die Kühe wurden basierend auf der Milchqualität in zwei Gruppen eingeteilt. Tiere welche eine SCC ≤400 Zellen/μl aufwiesen, gehörten zur Gruppe der guten Milchqualität. Die zweite Gruppe entsprach jenen Proben die sich >400 Zellen/μl befanden und somit einer niedrigeren Milchqualität entsprachen. Der Totalproteingehalt wurde mit einem digitalen Brixrefraktometer gemessen. Es wurden schließlich drei Korrelationen berechnet, betreffend der Milchqualität ante und post partum und dem Kolostrum sowie zwischen den Immunglobulinwerten und der SCC im Kolostrum. Letztere wurde mit dem Spearman Koeffizienten als -0,2 bestimmt. Der Wert deutete auf eine negative Beziehung der beiden Werte hin, war jedoch als sehr schwach einzustufen. Weitere Untersuchungen und ausgeglichenere Kohorten werden empfohlen, um diese Beziehung genauer zu analysieren.Diploma thesis - University of Veterinary Medicine Vienna - 2024In this study, the development of the pressure distribution of the footing areas of individual hooves of twelve foals within three month was analyzed based on a data set made available. The first measurement had taken place one to three days after birth, then weekly up to the fifth measurement and then at intervals of one month up to the sixth and seventh measurement, during each measurement, the foals were guided over pressure mats and filmed. The ASIs of the individual hoofprints were evaluated and the angles of the carpal, tarsal and fetlock joints were assessed both visually using the videos and measuring joint angles using still images selected from the videos. It was statistically checked by means of Pearson correlation whether there was a correlation between the joint angles and the hoof pressure distributions and how they developed over the study period. The pressure distribution of the forelimbs shifted from more dorsal to more palmar within the study period; there was no recognizable trend in the mediolateral direction. There was no discernible trend in either the dorsoplantar or mediolateral direction in the hindlimbs. The standard deviations of the pressure distributions and the joint angulations decreased within the study period. The average joint angles of the carpal and fetlock joints nearly approached 180° over the course of the study from being more carpus or fetlock valgus. The tarsal joint angles showed a slight tarsus valgus from the first to the last measurement. There was no clear significant correlation of joint angulations with hoof pressure distributions, so the system studied for assessing joint angulations in very young foals is not suitable for clinical use. It requires a high level of technical and personal effort and the data obtained do not allow any conclusions to be drawn about the joint angles
Genomes of historical specimens reveal multiple invasions of LTR retrotransposons in Drosophila melanogaster during the 19th century.
No full textTransposable element invasions have a profound impact on the evolution of genomes and phenotypes. It is thus an important open question how often such TE invasions occur. To address this question, we utilize the genomes of historical specimens, sampled about 200 y ago. We found that the LTR retrotransposons Blood, Opus, and 412 spread in Drosophila melanogaster in the 19th century. These invasions constitute second waves, as degraded fragments were found for all three TEs. The composition of Opus and 412, but not of Blood, shows a pronounced geographic heterogeneity, likely due to founder effects during the invasions. Finally, we identified species from the Drosophila simulans complex as the likely origin of the TEs. We show that in total, seven TE families invaded D. melanogaster during the last 200y, thereby increasing the genome size by up to 1.2Mbp. We suggest that this high rate of TE invasions was likely triggered by human activity. Based on the analysis of strains and specimens sampled at different times, we provide a detailed timeline of TE invasions, making D. melanogaster the first organism where the invasion history of TEs during the last two centuries could be inferred
Ichthyophthirius multifiliis, der Erreger der Ichthyophthiriose : ein Update (Literaturarbeit)
No full textDiplomarbeit - Veterinärmedizinische Universität Wien - 2024Die Krankheit ist ein großes Problem sowohl für gezüchtete als auch für wilde Süßwasserfische in allen Regionen der Welt. Die meisten Arten von Süßwasserfischen gelten als anfällig. Die klinischen Anzeichen einer I. multifiliis-Infektion sind durch bis zu 1 mm große weiße Flecken gekennzeichnet, die häufig auf der Haut und den Flossen infizierter Fische zu sehen sind. Der Parasit hat einen direkten Lebenszyklus und kann sich mit der von der Umgebungstemperatur abhängigen Entwicklungsgeschwindigkeit zu Hunderten von infektiösen Theronten vermehren. Innerhalb von ein bis zwei Wochen kann der Parasit ganze Fischherden bei ungünstigen Witterungsbedingungen oder Wasserbelastung töten. Früherkennungs- und Behandlungsstrategien sind entscheidend, um die Ausbreitung dieser Krankheit einzudämmen. Ichthyophthiriose führt zu schweren wirtschaftlichen Verlusten und hohe Mortalitätsrate. Der erste Ausbruch der Krankheit wurde im Jahr 1876 von dem französischen Parasitologie Fouquet beschrieben. Während des gesamten Lebenszyklus kann I. multifiliis in den Epithelien die Immunantwort seines Wirts aktivieren, während Theronts und Tomonts von einer Vielzahl von Faktoren in der aquatischen Umwelt beeinflusst werden. Zu den Hauptkrankheitsmerkmalen von mit Ciliaten infizierten Fischen gehört die schwarze Färbung; erhöhte Schleimproduktion; Schäden an Schuppen; hämorrhagische, entfärbte Stellen auf der Haut; und dermale nekrotische Läsionen, die letztendlich Gewebe schädigen, was zu hohen Mortalitätsraten führt. Verschiedene Behandlungen werden verwendet, um den Parasiten mit Behandlungsregimen zu bekämpfen. Gegenwärtige Behandlungen umfassen die Verabreichung von Formaldehyd, Natriumchlorid, Kupfersulfat und Kaliumpermanganat. Vermeintlich umweltfreundlichere Medikamente wie Huminsäure, Kaliumferrat (VI), Bronopol und die auf Peressigsäure basierenden Produkte wurden jedoch kürzlich getestet und stellen vielversprechende Alternativen dar. Weitere Untersuchungen sind erforderlich, um die Behandlungen zu optimieren und genaue Protokolle zu erstellen, um die Menge des verwendeten Arzneimittels zu minimieren und gleichzeitig die wirksamste Leistung sicherzustellen. Gleichzeitig muss den nicht-medikamentösen Aspekten der Managementstrategien größere Bedeutung beigemessen werden, einschließlich des Einsatzes nicht-chemischer Interventionen, die sich auf die Entfernung freischwimmender Stadien und Tomozysten von I. multifiliis aus landwirtschaftlichen Kultursystemen konzentrieren. Der Einsatz solcher Strategien lässt auf umweltfreundlichere Alternativen zur Bekämpfung von Ich Infektionen hoffen.Diploma thesis - University of Veterinary Medicine Vienna - 2024Ichthyophthirius multifiliis is a widely distributed ectoparasite of fish and has a significant impact on commercial aquaculture worldwide. It is a ciliate protozoan, which causes Ichthyophthiriasis or “white spot disease”. This parasite infects the skin, gills, fins, and eyes of fish and leads to severe economic losses in the aquaculture industry and high mortalities in ornamental-and food fish and epizootic in the population of wild fish. The closest living organism of Ich is Cryptocaryon irritans, but it affects marine fish. The life cycle consists of four main stages and all stages are ciliated and are affected by temperature and salinity of the water. Each stage of the parasite depends on a certain temperature. It is reported that the suitable temperature for the development of I. multifiliis is between 14 and 17.5°C, encystment between 13.1 and 25°C and the division of the cyst takes place in 24 hours at 16.2 to 25°C. There are several treatment trials to prevent and control the development of “Ich.” This can be drug or non-drug intervention. Malachite green was one of the most effective treatments of Ich because it is always available, its cost is low, it is easy to dissolve in water and it does not spoil or be affected by storage, but it has prevented in EU member states, the United States, and other countries from use in food fish because of its teratogenic effect. In this thesis, I will talk about the most important findings of researchers in terms of results and research on the ich parasite, what are the characteristics of this disease, how to control infection through some methods to prevent infection, and some treatments and immunizations necessary to control white spot disease
Computerisierte Messung der nukleären Pleomorphie mittels künstlicher Intelligenz als prognostisches Kriterium bei caninen Lungenkarzinomen
No full textDiplomarbeit - Veterinärmedizinische Universität Wien - 2024Nukleäre Pleomorphie (Variation der Zellkerngröße, u/o -form) ist ein prognostisches Malignitätskriterium im aktuellen Grading-System caniner Lungenkarzinome (cPC) und wird durch PathologInnen mittels eines dreistufigen Klassifizierungssystem eingeschätzt. Diese visuelle Graduierung ist anfällig für eine relevante Inter-observer Variabilität. Quantitativere Ansätze (manuelle Morphometrie) sind zeitaufwendig und somit impraktikabel. Wir haben einen Deep Learning-Algorithmus entwickelt, der die Zellkerne segmentiert und ihre morphometrischen Eigenschaften bewertet, um diese Limitationen zu überwinden. Die Bewertung der nukleären Pleomorphie wurde anschließend mit Schätzungen von PathologInnen und anderen etablierten prognostischen Tests verglichen und der prognostische Wert in cPC untersucht. Das Segmentierungsmodell wurde mittels eines Basisdatensatzes (27.138 annotierte Zellkerne in 43 cPC) entwickelt und validiert. Um die Genauigkeit des Modells und seine prognostische Fähigkeit zu beurteilen, wurde das Modell anschließend auf einen separaten Ergebnisdatensatz (46 cPC-Fälle mit verfügbarem Follow-Up) angewandt. Die Kernfläche (SD of area) zeigte eine gute Trennschärfe für das tumorspezifische Überleben, mit einer AUC von 0,80 und einer Hazard Ratio (HR) von 3,38 für die algorithmische Morphometrie. Zusätzlich zeigte die SD der Solidität, als Maß für die Unregelmäßigkeit der Kernform, ein vielversprechendes prognostisches Potenzial (AUC von 0,82). Die Schätzungen der PathologInnen ergaben HR-Werte zwischen 0,86 und 34,8, mit einer geringen Reproduzierbarkeit (k = 0,204) zwischen den BeobachterInnen. Andere prognostische Tests zeigten keine diskriminatorische Fähigkeit. Automatisierte Morphometrie verspricht eine zeiteffiziente und reproduzierbare Bewertung der nukleären Pleomorphie, die im Vergleich zu herkömmlichen Tests einen hohen prognostischen Wert hat. Eine Verfeinerung des Algorithmus, insbesondere im Hinblick auf die Untersegmentierung, und die Anwendung auf eine größere Studienpopulation sind in Zukunft gerechtfertigt.Diploma thesis - University of Veterinary Medicine Vienna - 2024Nuclear pleomorphism (variation in size, i.e., anisokaryosis, and/or shape) is a relevant malignancy criterion in canine pulmonary carcinoma (cPC) used in the current grading system. It is estimated by pathologists using a three-tier classification, presumably leading to relevant interobserver variability. A more quantitative approach (manual morphometry) is timeconsuming and therefore impractical. Measuring previously segmented nuclei provided by automated morphometry may overcome these limitations. We developed a deep learningbased algorithm and compared its assessment of nuclear pleomorphism to pathologists estimates and other prognostic tests, as well as the prognostic value of automated morphometry in cPC. A segmentation model was developed and tested using a ground truth dataset (27,138 annotated nuclei from 43 cPC). Subsequently, its performance was assessed on a separate outcome dataset consisting of 46 cPC cases with available follow-up information, evaluating the model’s accuracy and prognostic ability. Nuclear area (SD of area) showed good discriminative ability for tumor-specific survival, with an area under the curve (AUC) of 0.80 and hazard ratio (HR) of 3.38 for algorithmic morphometry. SD of solidity, reflecting shape irregularity, showed promising prognostic potential (AUC of 0.82). Pathologists\u27 estimates resulted in HR values from 0.86 to 34.8, with slight (k = 0.204) interobserver reproducibility. Other prognostic tests revealed no discriminatory ability. Automated morphometry promises a time efficient and reproducible assessment of nuclear pleomorphism that has a high prognostic value compared to conventional prognostic tests. Further refinement of the algorithm, particularly to address undersegmentation, and application to a larger study population are required in the future
Enterobacterales, Staphylococcus sp., Mammaliicoccus sp. and Enterococcus sp. isolated from ospreys (Pandion haliaetus) habituated in Mono Lake, California, USA, with special consideration of their antimicrobial resistance and virulence potential
No full textDiplomarbeit - Veterinärmedizinische Universität Wien - 2024
Aus rechtlichen Gründen sind nicht alle Teile dieser Arbeit frei zugänglich. Der Zugriff auf den elektronischen Volltext ist auf Angehörige der Veterinärmedizinischen Universität Wien beschränkt. Bitte einloggen!Die Übertragung von antibiotikaresistenten Bakterien und/oder Resistenzgenen zwischen Menschen, Tieren und der Umwelt stellt eine fortlaufende Herausforderung für die globale Gesundheit und ein sozioökonomisches Problem dar. Erworbene Antibiotikaresistenz wird häufig bei Bakterien der Ordnung Enterobacterales und der Gattungen Staphylococcus sp., Mammaliicoccus sp. und Enterococcus sp. beobachtet. Daten über das Vorkommen von Antibiotikaresistenzen in der Umwelt, einschließlich der Tierwelt, sind essentiell um die Übertragungswege und treibenden Faktoren zu verstehen. In dieser Studie wurden Kloakenproben von Fischadler Nestlingen (Pandion haliaetus) aus Mono Lake, Kalifornien, USA, untersucht und in einem mehrphasigen Ansatz mittels verschiedener Methoden charakterisiert, darunter Antibiotika- und Biozid-Empfindlichkeitstests, Genotypisierung und ausgewählte Isolate auch mittels Whole Genome Sequencing (WGS). Die am häufigsten entdeckten Spezies waren Escherichia (E.) coli, gefolgt von Mammaliicoccus sciuri, Staphylococcus delphini, Enterococcus faecalis, Enterococcus faecium, Hafnia alvei, Klebsiella pneumoniae und einzelne Isolate von Citrobacter braakii, Edwardsiella tarda, Edwardsiella albertii, Klebsiella aerogenes, Plesiomonas shigelloides und Staphylococcus pseudintermedius. Multiresistenz wurde in zwei E. coli Isolaten und einem Ent. faecium Isolat beobachtet. Ein multiresistentes blaCTX-M-55 positives E. coli Isolat gehörte zum pandemischen Klon Serotyp (ST) 58. Die Ergebnisse dieser Studie zeigen, dass Fischadler Nestlinge, wahrscheinlich durch die Aufnahme von kontaminiertem Fisch, multiresistenten Bakterien ausgesetzt sind. Dadurch stellen Fischadler möglicherweise gute Bioindikatoren für das Vorhandensein dieser Mikroorganismen und Antibiotikaresistenzen in der Umwelt dar.Diploma thesis - University of Veterinary Medicine Vienna - 2024
The full text is only available to university members. Please log in!No abstract available
Why do dogs wag their tails?
No full textTail wagging is a conspicuous behaviour in domestic dogs (Canis familiaris). Despite how much meaning humans attribute to this display, its quantitative description and evolutionary history are rarely studied. We summarize what is known about the mechanism, ontogeny, function and evolution of this behaviour. We suggest two hypotheses to explain its increased occurrence and frequency in dogs compared to other canids. During the domestication process, enhanced rhythmic tail wagging behaviour could have (i) arisen as a by-product of selection for other traits, such as docility and tameness, or (ii) been directly selected by humans, due to our proclivity for rhythmic stimuli. We invite testing of these hypotheses through neurobiological and ethological experiments, which will shed light on one of the most readily observed yet understudied animal behaviours. Targeted tail wagging research can be a window into both canine ethology and the evolutionary history of characteristic human traits, such as our ability to perceive and produce rhythmic behaviours
Cytotoxicity of Prymnesium parvum extracts and prymnesin analogs on epithelial fish gill cells RTgill-W1 and the human colon cell line HCEC-1CT
No full textHarmful algal blooms kill fish populations worldwide, as exemplified by the haptophyte microalga Prymnesium parvum. The suspected causative agents are prymnesins, categorized as A-, B-, and C-types based on backbone carbon atoms. Impacts of P. parvum extracts and purified prymnesins were tested on the epithelial rainbow trout fish gill cell line RTgill-W1 and on the human colon epithelial cells HCEC-1CT. Cytotoxic potencies ranked A > C > B-type with concentrations spanning from low (A- and C-type) to middle (B-type) nM ranges. Although RTgill-W1 cells were about twofold more sensitive than HCEC-1CT, the cytotoxicity of prymnesins is not limited to fish gills. Both cell lines responded rapidly to prymnesins; with EC50 values for B-types in RTgill-W1 cells of 110 ± 11 nM and 41.5 ± 0.6 nM after incubations times of 3 and 24 h. Results of fluorescence imaging and measured lytic effects suggest plasma membrane interactions. Postulating an osmotic imbalance as mechanisms of toxicity, incubations with prymnesins in media lacking either Cl-, Na+, or Ca2+ were performed. Cl- removal reduced morphometric rearrangements observed in RTgill-W1 and cytotoxicity in HCEC-1CT cells. Ca2+-free medium in RTgill-W1 cells exacerbated effects on the cell nuclei. Prymnesin composition of different P. parvum strains showed that analog composition within one type scarcely influenced the cytotoxic potential, while analog type potentially dictate potency. Overall, A-type prymnesins were the most potent ones in both cell lines followed by the C-types, and lastly B-types. Disturbance of Ca2+ and Cl- ionoregulation may be integral to prymnesin toxicity.A Correction to this article was published on 09 April 2024: https://doi.org/10.1007/s00204-024-03716-
A multinational survey of companion animal veterinary clinicians: How can antimicrobial stewardship guidelines be optimised for the target stakeholder?
No full textAntimicrobial stewardship initiatives are widely regarded as a cornerstone for ameliorating the global health impact of antimicrobial resistance. Within companion animal health, such efforts have largely focused on development and dissemination of antimicrobial stewardship guidelines (ASGs). However, there have been few attempts to understand veterinarian attitudes towards and knowledge of ASGs or to determine how awareness regarding ASGs might best be increased. An online survey regarding ASGs was formulated for veterinarians who treat companion animals. The survey was distributed across 46 European and associated countries between 12 January and 30 June, 2022. In total, 2271 surveys were completed, with 64.9% of respondents (n = 1474) reporting awareness and usage of at least one ASG. Respondents from countries with greater awareness of ASGs tended to report more appropriate use of antimicrobials (Spearman\u27s rank coefficient = 0.6084, P ≤ 0.001), with respondents from countries with country-specific ASGs tending to score highest across both awareness and appropriate use domains. Respondents prioritised guidance around antimicrobial choice (82.0%, n = 1863), duration of treatment (66.0%, n = 1499), and dosage (51.9%, n = 1179) for inclusion in future ASGs, with 78.0% (n = 1776) of respondents preferring ASGs to be integrated into their patient management system. Awareness of ASGs and their use in companion animal veterinary practice appears to be greater than previously reported, with respondents tending to report antimicrobial prescription decision making broadly in line with current clinical recommendations. However, further initiatives aimed at maximising accessibility to ASGs both within countries and individual veterinary practices are recommended