Precision-cut bovine udder slices (PCBUS) as an in-vitro-model of an early phase of infection of bovine mastitis

Background The aim of this study was to establish precision-cut bovine udder slices (PCBUS) as an in-vitro-model to investigate pathophysiological processes in the early phase of mastitis in order to have the possibility to investigate new therapeutic approaches for the treatment of such udder inflammation in later studies. Furthermore, this model should contribute to substitute in-vivo-experiments. Bovine mastitis is one of the most common and costly infectious diseases in the dairy industry, which is largely associated with the use of antimicrobial agents. Given this problem of antimicrobial resistance, it is essential to step up research into bacterial infectious diseases. Thus, the transfer of the in-vitro-model of precision-cut tissue slices to the bovine udder enables broad research into new therapeutic approaches in this area and can also be used to address issues in basic research or the characterisation of complex pathophysiological processes. Results A stimulation with LPS, PGN or the combination of both substances (LPS:PGN) demonstrates the ability of the PCBUS to react with a significant secretion of IL-1ß, TNF-α and PGE2. Conclusion The slices represent an instrument for investigating pharmacological interactions with udder tissue, which can be useful for studies on pharmacological questions and the understanding of complex pathophysiological processes of infection and inflammation

Effect of an Oxygen-Based Mechanical Drug Delivery System on Percutaneous Permeation of Various Substances In Vitro

Transdermal drug administration is an elegant method to overcome various side effects of oral or parenteral drug administration. Nevertheless, due to an effective skin barrier, which is provided by the stratum corneum, transdermal drug delivery is sometimes very slow and ineffective. Thus, the effect of a medical device (DERMADROP TDA) for transdermal penetration of drugs in conjunction with a special vehicle emulsion on percutaneous permeation of several substances (with different physicochemical properties) was investigated in Franz-type diffusion cells with porcine skin over 28 h. This medical device disperses pharmaceutical agents via oxygen flow through an application system, which is used in conjunction with specially developed vehicle substances. Substance permeation of various substances with different physicochemical properties (diclofenac, enrofloxacin, flufenamic acid, indomethacin, and salicylic acid) was examined after application with a pipette and with the medical device. Therefore, acceptor media samples were collected up to 28 h after drug administration. Drug concentration in the acceptor medium was determined via high-performance liquid chromatography. Enhanced permeation was observed for diclofenac, enrofloxacin, flufenamic acid, indomethacin, and salicylic acid after oxygen-based administration. This correlates negatively with the molecular weight. Thus, drug administration can effectively be enhanced by a medical device using oxygen

Influence of PEG Chain Length of Functionalized Magnetic Nanoparticles on the Cytocompatibility and Immune Competence of Primary Murine Macrophages and Dendritic Cells

A major drawback of nanoparticles (NPs) for biomedical applications is their preferential phagocytosis in immune cells, which can be avoided by surface modifications like PEGylation. Nevertheless, examinations of different polyethylene glycol (PEG) chain lengths on the competence of immune cells as well as possible immunotoxic effects are still sparse. Therefore, primary murine macrophages and dendritic cells were generated and incubated with magnetic nanoporous silica nanoparticles (MNPSNPs) modified with different mPEG chains (2 kDa, 5 kDa, and 10 kDa). Cytotoxicity, cytokine release, and the formation of reactive oxygen species (ROS) were determined. Immune competence of both cell types was examined and uptake of MNPSNPs into macrophages was visualized. Concentrations up to 150 µg/mL MNPSNPs showed no effects on the metabolic activity or immune competence of both cell types. However, ROS significantly increased in macrophages incubated with larger PEG chains, while the concentration of cytokines (TNF-α and IL-6) did not indicate a proinflammatory process. Investigations on the uptake of MNPSNPs revealed no differences in the onset of internalization and the intensity of intracellular fluorescence. The study gives no indication for an immunotoxic effect of PEGylated MNPSNPs. Nevertheless, there is still a need for optimization regarding their internalization to ensure an efficient drug delivery

Investigation of the pathophysiology of bacterial mastitis using precision-cut bovine udder slices

Mastitis in cattle is a major health problem as well as incurring high costs for the dairy industry. To assess the suitability of precision-cut bovine udder slices (PCBUS) for bovine mastitis studies, we infected PCBUS with 2 different Staphylococcus aureus strains. Accordingly, we investigated both the tissue response to infection based on immune mediators at the mRNA and protein levels and the invasion of bacteria within the tissue. The studied proteins represent immune mediators of early inflammation [IL-1β, tumor necrosis factor-α (TNF-α), prostaglandin E2 (PGE2)] and showed a time-dependent increase in concentration. Infection of PCBUS with S. aureus resulted in increased expression of proinflammatory cytokines and chemokines such as TNF-α, C-C motif chemokine ligand 20 (CCL20), IL-1β, IL-6, and IL-10, but not C-X-C motif chemokine ligand 8 (CXCL8), lingual antimicrobial peptide (LAP), or S100 calcium binding protein A9 (S100A9) at the mRNA level. To compare the data acquired with this model, we carried out investigations on primary bovine mammary epithelial cells. Our results showed that the immune responses of both models - PCBUS and primary bovine mammary epithelial cells - were similar. In addition, investigations using PCBUS enabled us to demonstrate adherence of bacteria in the physiological cell network. These findings support the use of PCBUS in studies designed to further understand the complex pathophysiological processes of infection and inflammation in bovine mastitis and to investigate alternative therapies for mastitis

FeMn with Phases of a Degradable Ag Alloy for Residue-Free and Adapted Bioresorbability

The development of bioresorbable materials for temporary implantation enables progress in medical technology. Iron (Fe)-based degradable materials are biocompatible and exhibit good mechanical properties, but their degradation rate is low. Aside from alloying with Manganese (Mn), the creation of phases with high electrochemical potential such as silver (Ag) phases to cause the anodic dissolution of FeMn is promising. However, to enable residue-free dissolution, the Ag needs to be modified. This concern is addressed, as FeMn modified with a degradable Ag-Calcium-Lanthanum (AgCaLa) alloy is investigated. The electrochemical properties and the degradation behavior are determined via a static immersion test. The local differences in electrochemical potential increase the degradation rate (low pH values), and the formation of gaps around the Ag phases (neutral pH values) demonstrates the benefit of the strategy. Nevertheless, the formation of corrosion-inhibiting layers avoids an increased degradation rate under a neutral pH value. The complete bioresorption of the material is possible since the phases of the degradable AgCaLa alloy dissolve after the FeMn matrix. Cell viability tests reveal biocompatibility, and the antibacterial activity of the degradation supernatant is observed. Thus, FeMn modified with degradable AgCaLa phases is promising as a bioresorbable material if corrosion-inhibiting layers can be diminished

Preparation and PET/CT imaging of implant directed 68Ga-labeled magnetic nanoporous silica nanoparticles

Background: Implant infections caused by biofilm forming bacteria are a major threat in orthopedic surgery. Delivering antibiotics directly to an implant affected by a bacterial biofilm via superparamagnetic nanoporous silica nanoparticles could present a promising approach. Nevertheless, short blood circulation half-life because of rapid interactions of nanoparticles with the host’s immune system hinder them from being clinically used. The aim of this study was to determine the temporal in vivo resolution of magnetic nanoporous silica nanoparticle (MNPSNP) distribution and the effect of PEGylation and clodronate application using PET/CT imaging and gamma counting in an implant mouse model. Methods: PEGylated and non-PEGylated MNPSNPs were radiolabeled with gallium-68 (68Ga), implementing the chelator tris(hydroxypyridinone). 36 mice were included in the study, 24 mice received a magnetic implant subcutaneously on the left and a titanium implant on the right hind leg. MNPSNP pharmacokinetics and implant accumulation was analyzed in dependence on PEGylation and additional clodronate application. Subsequently gamma counting was performed for further final analysis. Results: The pharmacokinetics and biodistribution of all radiolabeled nanoparticles could clearly be visualized and followed by dynamic PET/CT imaging. Both variants of 68Ga-labeled MNPSNP accumulated mainly in liver and spleen. PEGylation of the nanoparticles already resulted in lower liver uptakes. Combination with macrophage depletion led to a highly significant effect whereas macrophage depletion alone could not reveal significant differences. Although MNPSNP accumulation around implants was low in comparison to the inner organs in PET/CT imaging, gamma counting displayed a significantly higher %I.D./g for the tissue surrounding the magnetic implants compared to the titanium control. Additional PEGylation and/or macrophage depletion revealed no significant differences regarding nanoparticle accumulation at the implantation site. Conclusion: Tracking of 68Ga-labeled nanoparticles in a mouse model in the first critical hours post-injection by PET/CT imaging provided a better understanding of MNPSNP distribution, elimination and accumulation. Although PEGylation increases circulation time, nanoparticle accumulation at the implantation site was still insufficient for infection treatment and additional efforts are needed to increase local accumulation

Analysis of dynamic influences on the human locomotor system and possibilities of transfer to human models for use in Blender

Das Ziel dieser Arbeit ist die Untersuchung der in Blender vorhandenen Tools zur Erstellung einer Fallsimulation mit einfachen Objekten und Menschmodellen. Nach einem kurzen Überblick über die Theorie werden verschiedene Kräfte in mehreren Testreihen untersucht und schlussendlich kombiniert. Diese Testreihen werden mit dem Programm Blender durchgeführt. Zusätzlich wurde eine Anleitung zur Erstellung einer Ragdoll in Blender 2.8 an-gefertigt

Cooperative protection of peatlands with Landcare Associations (LCA)

Bei der DGMT Jahrestagung 2017 wurden die Aktivitäten des Deutschen Verbands für Landschaftspflege e. V. (DVL) und der Landschaftspflegeverbände im Moor- und Klimaschutz vorgestellt. Der Dachverband von 170 Landschaftspflegeverbänden ist Partner der Nationalen Klimaschutzinitiative des Bundesministeriums für Umwelt, Naturschutz und nukleare Sicherheit. Im Projekt „Beratung und Coaching zum Thema Moorschutz“ unterstützt der DVL in Brandenburg, Mecklenburg-Vorpommern und Niedersachsen Landschaftspflegeverbände und regionale Initiativen, Moorschutz in Ihrer Region kooperativ umzusetzen. Lokale Akteurinnen und Akteure u. a. aus Naturschutz, Landwirtschaft und Politik werden beraten und untereinander sowie bundesweit mit Fachleuten vernetzt. Die langfristige Pflege von Schutzgebieten, Fördermöglichkeiten für landwirtschaftlichen Naturschutz sowie Regionalvermarktungskonzepte in Moorgebieten sind häufige Themen bei den Gesprächen. Die freiwillige Zusammenarbeit gleichberechtigter Partnerinnen und Partner aus Landwirtschaft, Naturschutz und Politik ist Grundsatz eines Landschaftspflegeverbands (LPV). Mehrere LPVs sind bereits im Moorschutz aktiv, wie seit fast 30 Jahren die ARGE Donaumoos. Aufgrund der intensiven Beteiligung aller Akteure vor Ort konnte hier in der stark genutzten Landschaft die erste flächige Wiedervernässung eines Niedermoores in Bayern einig mit Erfolg ausgeführt werden. Dabei war der kooperative Ansatz bei Problemlösungen ein entscheidender Schlüsselfaktor.At the yearly conference of the DGMT 2017 the activities of the German Association of Landcare (DVL) and the Landcare Associations (LCA) in peatland and climate protection were discussed. The umbrella association of 170 LCAs is partner of the National Climate Initiative of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU). With the project “Consulting and coaching for peatland protection” the DVL supports LCAs and other regional initiatives in Brandenburg/Berlin, Mecklenburg Western Pomerania and Lower Saxony that want to implement peatland protection in their region in a cooperative way. The DVL consults local stakeholders from agriculture, nature conservation and local communities and links them with each other as well with experts on the national level. Common topics in the regions are the long-term maintenance of conservation areas, financing of agri-environmental acitvities and regional marketing in peatland areas. The basis of the LCAs is the voluntary and close cooperation of local farmers, nature conservation groups and local communities that work together on equal terms. Some LCAs already practice peatland conservation. The Arbeitsgemeinschaft Schwäbisches Donaumoos (ARGE Donaumoos) for example was founded already almost 30 years ago. Due to the intensive participation of all local stakeholders in the area, the first large-area rewetting of a fen in Bavaria could be completed successfully. Here the cooperation of all stakeholders was an essential key factor to tackle challenges.DFG, SUB Göttingen, DGMTresearc

Influence of the H1 Antihistamine Mepyramine on the Antibacterial Effect of Florfenicol in Pigs

The effect of florfenicol against Escherichia coli (E. coli) was investigated in vivo to confirm results of an in vitro study of Bruer et al. (2019), which has shown positive effects of various antibacterial agents in combination with the antihistamine mepyramine (MEP). Therefore, pigs were treated in three different settings: An untreated control group, 10 mg/kg florfenicol (FFC) and 10 mg/kg FFC in combination with 20 mg/kg MEP. E. coli were isolated from faecal samples and analyzed in growth quantity and resistance to FFC. The FFC medication induced an increased number of resistant E. coli strains isolated from faecal samples. The number of colonies detected after cultivation of animal samples treated with 10 mg/kg FFC was higher than the number of colonies after treatment with 10 mg/kg FFC in combination with of FFC and MEP. Furthermore, the effect of both compounds was examined on bacterial susceptibility of Pasteurella multocida in vitro, where the combination of FFC with MEP resulted in a diminished minimum inhibitory concentration. We confirmed the development of bacterial resistance in the intestine as non-target tissue caused by the use of the antibacterial agent florfenicol. Moreover, the combination of FFC with an antihistamine like MEP offers a possibility to enhance the efficacy of an antibacterial treatment and modifies the effect on gut microbiota

Effect of an Oxygen-Based Mechanical Drug Delivery System on Percutaneous Permeation of Various Substances In Vitro

Transdermal drug administration is an elegant method to overcome various side effects of oral or parenteral drug administration. Nevertheless, due to an effective skin barrier, which is provided by the stratum corneum, transdermal drug delivery is sometimes very slow and ineffective. Thus, the effect of a medical device (DERMADROP TDA) for transdermal penetration of drugs in conjunction with a special vehicle emulsion on percutaneous permeation of several substances (with different physicochemical properties) was investigated in Franz-type diffusion cells with porcine skin over 28 h. This medical device disperses pharmaceutical agents via oxygen flow through an application system, which is used in conjunction with specially developed vehicle substances. Substance permeation of various substances with different physicochemical properties (diclofenac, enrofloxacin, flufenamic acid, indomethacin, and salicylic acid) was examined after application with a pipette and with the medical device. Therefore, acceptor media samples were collected up to 28 h after drug administration. Drug concentration in the acceptor medium was determined via high-performance liquid chromatography. Enhanced permeation was observed for diclofenac, enrofloxacin, flufenamic acid, indomethacin, and salicylic acid after oxygen-based administration. This correlates negatively with the molecular weight. Thus, drug administration can effectively be enhanced by a medical device using oxygen