Research

Project Details:
The gastrointestinal tract is constantly exposed to considerable challenges. As a consequence of bacterial and dietary antigens found in the lumen, the intestine displays a low-grade physiological inflammation. Under pathological conditions, such as the inflammatory bowel disease (IBD), the intestinal mucosa is infiltrated by inflammatory cells including neutrophils, macrophages, and lymphocytes. The inflammatory cells homing to the intestinal mucosa come in close proximity to the intestinal epithelial cell (IEC) layer, and may be involved in induction of the functional impairment of IECs. Three essential mechanisms may contribute to the induction of this state: (i) soluble mediators secreted by inflammatory cells, (ii) direct adhesion and signaling molecules expressed on the surface of immune cells and epithelial cells and (iii) cytoplasmic exchange of specific signals between the inflammatory cells and IECs via gap junction (GJ) channels. Gap junctions (GJ) are clusters of intercellular channels, which allow a direct exchange of ions and signalling metabolites of low molecular weight (less than 2 kDa) between adjacent cells. Gap junction channels span the plasma membranes of two adjacent cells and are composed of members of highly homologous family of proteins known collectively as connexins (Cx), which are named according to their theoretical molecular weight. Connexin 43 is the most abundant and widely spread connexin in human body which has been intensively studied for its role in inflammatory conditions. Our recent study (Cross-talk between intestinal epithelial cells and immune cells in inflammatory bowel disease. Al-Ghadban S, Kaissi S, Homaidan FR, Naim HY, El-Sabban ME. Sci Rep. 2016 Jul 15;6:29783. doi: 10.1038/srep29783.) and preliminary work have shown that IECs and immune cells (macrophages) are expressing Cx26 and Cx43 proteins and are able to create functional homo- and hetero-cellular GJs.
This project aims to study the expression and regulation of Cx43 in intestinal epithelial cells (IECs) under normal and inflammatory conditions. The IECs to be utilized in this proposal are Caco-2 cells, which is a colorectal adenocarcinoma cell line widely used as models of intestinal transport and in pathology including inflammation. Moreover, post-biosynthetic assembly into functional homo- or heterotypic connexons and their trafficking to the plasma membrane will be investigated. Here special interest would be on analysing the mode of interaction of Cxs with cellular membranes specifically caveolin-rich membrane domains. Additionally, since important aspect of this proposal is to study the involvement of gap junction dependent cell-to-cell communication in the pathobiology of IBD, we will analyse whether the inflammatory reactions related to the induction of IBD have an effect on gap junction coupling and all above-mentioned processes. These data would be essential for understanding the physiological role of Cxs in IECs in more details and would shed more light onto possible changes in their function that happen upon IBD development and contribute to the progression of the disease.

Cooperation Partners:

Prof. Dr. Marwan El-Sabban, Medical Faculty, American University of Beirut, Libanon

Funding: Bundesinstitut für Risikobewertung, Berlin

Project Details:
The project VetCAb (Veterinary Consumption of Antibiotics) is a research project that is carried out to describe the use of antibiotics in farm animals in Germany. In 2007 and 2008 the project was conducted as a feasibility study and subsequently in 2011 a pilot study in a cross-sectional approach. The pilot study not only documented the consumption of antibiotics based on of individual farm information, but also directly related it to the livestock, so that a risk assessment can be realized. This defined a status quo for Germany, which made it possible to determine measures to reduce the use of antibiotics in farm animals.

Building on this, the VetCAb-Sentinel project is continued from 2013 as a longitudinal study with ongoing participant recruitment and data collection. The aim of the study is to evaluate how often the animals are treated with antibiotics during a defined period of time based on the treatment frequency (TF), i.e. # treated animals x # treatment days / # animals per farm. In addition, the study will, among other things, investigate whether regions or farm sizes differ with regard to the use of antibiotics and which classes of active substances are used in German livestock farming. VetCAb-Sentinel thus forms the basis of a scientific risk assessment, which, according to the DART (Deutsche Antibiotika Resistenzstrategie), makes a significant contribution to the reduction of antibiotic resistance.

https://ibei.tiho-hannover.de/vetcab

Results:

https://ibei.tiho-hannover.de/vetcab/

https://ibei.tiho-hannover.de/vetcab/pages/41

Project Details:
Ein unspezifisches chronisches Krankheitsgeschehen wurde mit einer Toxikoinfektion mit Clostridium botulinum (sog. viszeraler/chronischer Botulismus) in Verbindung gebracht. Unter anderem wurde von typischen Lahmheitssymptomen berichtet. In einer Fall-Kontroll-Studie konnte ein Zusammenhang zwischen dem chronischen Krankheitsgeschehen und Clostridium botulinum nicht nachgewiesen werden. Chronisch kranke Tiere aus Kontroll- und Fallbetrieben waren aber vermehrt lahm, wobei die Lahmheit überwiegend durch Erkrankung an den Klauen zustande kam. In vorliegendem Projekt wird untersucht, ob sich lahme Kühe aus Kontroll- und Fallbetrieben hinsichtlich der Diagnosen an den Klauen unterscheiden. In einer Risikofaktorenanalyse wurden weiterhin verschiedene Faktoren aus Haltung, Fütterung und Management auf mögliche Beziehungen zur Anzahl der Klauendiagnosen pro Tier untersucht.

Cooperation Partners:

Vereinigte Informationssysteme Tierhaltung w.V.(vit)

Project Details:
Unsere Hypothese ist, dass die endoskopische Besamung im Vergleich zur üblichen manuell-transvaginalen Besamung in den Gebärmutterkörper eine graduell verstärkte reaktive Entzündungsreaktion verursacht. Hierzu soll die reaktive Entzündungsreaktion des Endometriums (mit und ohne Samenübertragung) durch versuchsbegleitende Probengewinnung (Endometriumabstriche für bakteriologische und zytologische Untersuchungen, Uterusbiopsie zur pathohistologischen Untersuchung des Endometriums) verglichen werden.

Results:

doi: 10.1016/j.jevs.2020.103023. PMID: 32534786

Cooperation Partners:

Niedersächsisches Landgestüt Celle

Institut für Veterinär-Pathologie, Universität Leipzig

Funding: 5.000 EUR

Project Details:
Die Tierärztliche Hochschule Hannover hat von der Landwirtschaftlich-Gärtnerischen Fakultät der Humboldt-Universität Berlin eine Miniaturschweinepopulation (Mini-LEWE) übernommen, die sich vom Göttinger Miniaturschwein unterscheidet. Die Sauen, Eber und deren Nachkommen sollen regelmäßig klinisch und labordiagnostisch hinsichtlich verschiedener Gesundheitsparameter untersucht werden.
Die Anpaarungen werden entsprechend der Abstammung und genetischen Diversität optmimiert.
Die Mini-Lewe Population ist eine sehr wichtige Ressource für biomedizinische Versuche und eine erhaltungswürdie Population.
Die genetische Charakterisierung dieser Population erfolgt über populationsgenetische Kennzahlen zur Verwandtschaft, Inzuchtzunahme, effektive Populationsgröße, Inzuchtgrad und erwartete Inzuchtzunahme. Tiefergehende Analysen beruhen auf genomweiten Markersystemen, Beadchip-Genotypisierungen und Komplettgenomanalysen. Diese Daten geben Einblick in die genomische Architektur, genomische Verwandtschaft, genomische Diversität, Selektionssignaturen und ROH-Inseln.
Für spezifische Versuche werden Haplotypen von Genclustern und Gengruppen charakterisiert, um Tiere für Versuche auswählen zu können.

Results:

Reimer et al. 2018. Analysis of porcine body size variation using re-sequencing data of miniature and large pigs. BMC Genomics. 2018 Sep 19;19(1):687. doi: 10.1186/s12864-018-5009-y.

 

Schachler et al. Schätzung der genetischen Diversität der Mini-Lewe Zuchtpopulation und Einfluss von Inzucht auf Wurfgrößenmerkmale

Züchtungskunde, 91, (3) S. 227-245, 2019, ISSN 0044-5401

https://elib.tiho-hannover.de/receive/etd_mods_00000392?q=Richel

Cooperation Partners:

Prof. Dr. Rainer Blasczyk, MHH

Prof. Dr. Sabine Hammer, Vetmed Uni Wien

Funding: Alexander von Humboldt Stiftung Mohammed Bin Zayed Species Conservation

Project Details:
The genus Eleutherodactylus, with over 194 known species and a distribution centered in the Caribbean West Indian islands, is the most speciose lineage of the Eleutherodactylidae family. These frogs represent over 80% of the Caribbean amphibian diversity with most of the species being single-island endemics. With the aid of multiple collaborators, this long term research project seeks to: 1) uncover cryptic diversity and define the species limits in the genus Eleutherodactylus by integrating genomic and phenotypic information; 2) elucidate the phylogenetic relationships among the species and related taxa; 3) compare the phenotypes, geographic distributions and evolutionary history across species to identify the factors responsible for the evolutionary diversification of amphibians in an insular scenario; and 4) generalize the results towards the long term conservation of these species.

Cooperation Partners:

Dr. Roberto Alonso Bosch, University of Havana, Cuba

MSc. Manuel Iturriaga Monsibay, Institute of Ecology and Systematics, Cuba

Prof. Dr. Miguel Vences, Technische Universität Braunschweig, Germany

Dr. Carles Vilà, Estación Biológica de Doñana, CSIC, Spain

Dr. Alejandro Gonzalez Voyer, Instituto de Ecología, UNAM, Mexico

Álvaro Dugo Cota, Estación Biológica de Doñana, CSIC, Spain

Funding: Private Personen und Kliniken Zuchtverbände, 30.000 EUR

Project Details:
Chromosomenmutationen können die Ursache von Fruchtbarkeitsstörungen, Intersexualität oder Missbildungen bei unseren Haussäugetieren sein. In diesen Fällen kann eine Chromosomendarstellung, zum Beispiel aus den Blutlymphozyten oder aus einer Gewebekultur, zur Klärung der Ursache beitragen.
Neben den klassischen Methoden der Zytogenetik zur Detektion von Chromosomenmutationen bei Einzeltieren werden zudem Gene mittels einer Fluoreszenz in situ Hybridisierung physikalisch am Genom der verschiedenen Spezies kartiert.

Results:

Iannuzzi A, Braun M, Genualdo V, Perucatti A, Reinartz S, Proios I, Heppelmann M, Rehage J, Hülskötter K, Beineke A, Metzger J, Distl O., Clinical, cytogenetic and molecular genetic characterization of a tandem fusion translocation in a male Holstein cattle with congenital hypospadias and a ventricular septal defect. PLoS One. 2020 Jan 10;15(1):e0227117. doi: 10.1371/journal.pone.0227117. eCollection 2020.

Funding: Bundesamt für Gewässerkunde, Koblenz, 16.588 EUR

Project Details:
In this project dead otters from Lower Saxony will be autopsied and examined. In this context, the parameters age, sex, nutritional status and primary cause of death will be determined, as far as the conservation status allows. In addition to a macroscopic examination, histological sections of the livers in particular will be prepared and examined in order to determine any changes. Furthermore, homogenized sample material from the removed liver tissue will be provided by the BFG for chemical analyses and fat determination. Furthermore, the BFG will be provided with already processed otter liver samples from the otter mortality monitoring Schleswig-Holstein, for chemical analyses and fat determination.
A summary of the diagnostic findings and the discovery data, i.e. location and date of discovery, conservation status, and, if applicable, information on the cause of death, will be provided in report form.

Results:

Report on the commission "Provision of tissue samples from otters from Lower Saxony for chemical residue analyses""."

https://www.tiho-hannover.de/fileadmin/57_79_terr_aqua_Wildtierforschung/79_Buesum/downloads/Berichte/Fischotterbericht_Rodentizide_Dez_2020_Gewebeproben_BfG.pdf

Funding: Verein der Förderer der Wildtierforschung an der Stiftung Tierärztliche Hochschule Hannover e. V., 2.100 EUR

Project Details:
Aufgrund der ersten vielversprechenden Ergebnisse der Pilotstudie wird angestrebt, die erhobenen Daten zur Raumnutzung von Katzen zu verifizieren. Dazu sollen weitere Katzen mit GPS Halsbändern ausgestattet werden. Insgesamt wird eine Individuenzahl von mindestsens 20 weiteren Katzen angestrebt, um eine ausreichend große Datengrundlage zu schaffen und die Raumnutzung der Hauskatze umfassender beurteilen zu können.
Die gewonnenen Daten werden mit verschiedenen statistischen Methoden analysiert und modelliert

Funding: Bundesamt für Naturschutz, 46.404 EUR

Project Details:
The aim of the project was to check whether there are indications that harbor porpoises were harmed and affected by the blasting of ground mines from the 2nd World War, which took place in the area of the nature reserve "Fehmarnbelt"". For this purpose, harbor porpoises and their body parts, which were collected in Schleswig-Holstein, Mecklenburg-Vorpommern and Denmark and were still available, were examined for health damage in relation to effects of blasting. The aim was to check not only for immediate lethal damage, but also for sublethal changes. These can result in porpoises being less able to find food and orient themselves. This in turn increases the risk of becoming ill, as well as being exposed to collision trauma or bycatch. Here, the exclusion procedure was used to evaluate whether the findings that were collected were caused by other causes. With the agreement of MELUND, data collected during the annual harbor porpoise mortality monitoring were included in an assessment of this particular issue. "

Results:

Siebert, U., Stürznickel, J., Schaffeld., T., Oheim, R., Rolvien, T., Prenger-Berninghoff, E., Wohlsein, P., Lakemeyer, J., Rohner, S., Schick, L.A., Gross, S., Nachtsheim, D., Ewers, C., Becher, P., Amling, M., Morell, M. 2022. Blast injury on harbour porpoises (Phocoena phocoena) from the Baltic Sea after explosions of deposits of World War II ammunition. Environment International 159, 107014. https://doi.org/10.1016/j.envint.2021.107014

https://doi.org/10.1016/j.envint.2021.107014