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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Visualizing the inhibitory power of a novel protein against Citrobacter and Enterobacter biofilms.

Wanamaker, Salem, Walker, Bailey, Fox, Sean 05 April 2018 (has links)
Microorganisms, particularly bacteria, can associate together to form complex communities called biofilms. These communities are embedded in extracellular polymeric substances and can form on numerous surfaces such as implanted devices (catheters, central lines, joint replacement) in patients. These biofilms cause bloodstream and systemic infections that are difficult to treat and increase the chances of sepsis. Previously, our laboratory has identified a protein secreted by Klebsiella that has inhibitory effects on other members of the Enterobacteriacea bacterial family, namely Citrobacter and Enterobacter. Our current interest lies in the ability of the protein to potentially inhibit this bacterial family from establishing biofilms. In the present study, we wanted to explore: (1) if it is possible to form Citrobacter and Enterobacter biofilms in 6-well plates and on microscope coverslips; (2) if treating these biofilms with the secreted protein shows inhibition similar to previous planktonic cultures; (3) if these biofilms and inhibition could be visualized by a variety of staining techniques. To determine if it is possible to create Citrobacter and Enterobacter biofilms, bacteria were inoculated into 6-well plates, grown under static conditions in a 37°C incubator for 24 hours, and stained with crystal violet. Images showed that robust biofilms grew in the 6-well control plates while wells treated with the Klebsiella protein displayed reduced biofilms. To determine if it was possible to see Citrobacter and Enterobacter biofilms at a microscopic level, microscope slides were placed into 6-well plates, treated as above, and the slides were Gram stained. Images show thick biofilms consisting of Gram negative rods on control slides, while slides treated with the Klebsiella molecule become sparse and poorly grown. To determine if Citrobacter and Enterobacter biofilms could be fluorescently labeled for visualization, the same process was employed as above, but stained with a LIVE/DEAD cell viability kit where live cells fluoresce green and dead cells fluoresce red. Control slides showed bright thick green fluorescing biofilms while slides treated with the Klebsiella molecule had fewer green fluorescing cells and some red cells. From these observations, it is our conclusion that: (1) it is possible to grow Citrobacter and Enterobacter biofilms on both 6-well plates and microscope slides; (2) Citrobacter and Enterobacter biofilms can be visualized both by simple staining and fluorescent staining; (3) Citrobacter and Enterobacter biofilms are inhibited by Klebsiella secreted proteins. Currently, the identity of this protein is unknown. However, it is possible that this unknown protein could be of future use in the treatment of bacterial biofilms one identified.
272

Elektrochemische Abscheidung von Bruschitschichten auf Titan in Gegenwart von Kristallisationsinhibitoren zur Steuerung von Kristallitgröße und biologischer Reaktion / Brushite coatings on titanium by electrochemical deposition in the presence of crystallization inhibitors to control of crystallite size and biological reaction

Wettstein, Lars January 2020 (has links) (PDF)
Es erfolgte eine elektrochemische Abscheidung von Bruschitschichten auf Titan in Gegenwart von Kristallisationsinhibitoren. Dabei wurden die Kristallisationsinhibitoren Zitronensäure, treta-Natriumdiphosphat-Decahydrat und Phytinsäure verwendet und die entstandenen Schichten mit denen ohne Inhibitorzugabe verglichen. Um das Ausmaß der Inhibierung zu verifizieren, wurde die Masse aller Schichten gemessen, welche für die Inhibition mit Zitronensäure und Phytinsäure abnahm und für Natriumdiphosphat zunahm. Die kristallographische Zusammensetzung der mit und ohne Inhibierung abgeschiedenen Schichten wurde mit Hilfe der Röntgendiffraktometrie bestimmt und zeigte, dass sich reine Bruschitschichten mit unterschiedlichem amorphem Anteil abschieden. Die daraus entstandenen Werte lieferten zugleich die Informationen über die einzelnen Kristallitgrößen innerhalb der Schichten. Über den Einfluss der Inhibitoren auf die Schichtmorphologie gaben rasterelektronenmikroskopische Aufnahmen weiteren Aufschluss. Die Inhibition verursachte teils mit Rissen durchzogene Schichten, deren Kristallformationen sich von Standardelektrolyt unterschieden. Ausgewählte Proben wurden unter verschiedenen Bedingungen desinfiziert bzw. sterilisiert und nachfolgend erneut gewogen und mittels Röntgendiffraktogrammetrie und Rasterelektronenmikroskopie analysiert. Nach der Desinfektion entstanden reine Bruschitschichten, die an Masse verloren aber trotzdem die typischen Kristallformationen zeigten. Die Sterilisation führte zur Umwandlung von Bruschit in Monetit und Hydroxylapatit. Des Weiteren wurde die biologische Reaktion der Schichten auf humane fötale Osteoblasten-Zelllinien zur Überprüfung der Zellverträglichkeit ermittelt. Die entstandenen Ergebnisse waren nicht verwertbar und enthielt sehr hohe Standardabweichungen. / Brushite coatings were deposited on titanium by electrochemical deposition in the presence of various crystallization inhibitors such as citric acid, treta-sodium diphosphate decahydrate and phytic acid. The resulting layers were compared with those without inhibitor addition. To verify the extent of inhibition, the mass of all layers was measured, which decreased for inhibition with citric acid and phytic acid and increased for sodium diphosphate. The crystallographic composition of the layers deposited with and without inhibition was determined by X-ray diffraction and showed pure brushite caotings with different amorphous content. The resulting values also provided information about the individual crystallite sizes within the layers. Scanning electron microscope images provided further information about the influence of the inhibitors of the layer morphology. The inhibition caused layers partly interspersed with cracks, whose crystal formations differed from the standard electrolyte. Selected samples were disinfected or sterilized under various conditions and subsequently reweighed and analyzed by X-ray diffraction and scanning electron microscopy. After disinfection, pure brushite caotings were formed, which lost mass but still showed the typical crystal formations. Sterilization led to the transformation of brushite into monetite and hydroxyapatite. Furthermore, the biological response of the layers to human fetal osteoblast cell lines was determined to test cell compatibility. The results obtained were not usable and contained very high standard deviations.
273

Corrosion inhibition study of AZ31 Mg alloy by Vanadate, Selenite and Phosphate

Feng, Zhiyuan January 2019 (has links)
No description available.
274

Molecular Understanding and Design of (I) Amyloid Inhibition and Cross-seeding and (II) Functional, Tough Hydrogels

ZHANG, YANXIAN 28 April 2021 (has links)
No description available.
275

The Impact of Brief Mindfulness Interventions on Attentional Control in Anxious Undergraduates: A Randomized Controlled Study

Aiello, Megan 01 December 2016 (has links) (PDF)
Mindfulness practice is associated with reduced anxiety, enhanced tolerance of negative affect, lower stress reactivity, improved task concentration, increased cognitive flexibility, and enhanced neurological functioning. However, mindfulness-based treatments are highly varied in duration, type and extent or training provided, and treatment focus. Studies of mindfulness interventions also often fail to operationally define mindfulness, which poses a challenging for understanding the mechanism(s) of change involved in its anxiolytic effects. In the current study, attentional control was examined as a possible mechanism of change, as it is largely deficient in individuals with anxiety yet necessary for extinction learning in treatment. In theory, mindfulness interventions can facilitate increased attentional control during exposure tasks, thereby enhancing new learning and eventually improving treatment outcomes. Using a randomized controlled design, the current study aimed to investigate the effects of mindfulness on attentional control for anxious individuals, with a specific examination of two types of mindfulness exercises: mindful physiological awareness and mindful acceptance. 142 participants were recruited from undergraduate psychology classes at Southern Illinois University, of which 63 had moderate-high trait anxiety and 79 had low trait anxiety (per STAI-Trait score). All participants completed baseline self-report questionnaires, after which they completed a mixed saccade task followed by listening to a 15-minute audio-recorded intervention based on group assignment. Finally, they completed a post-test mixed saccade task and post-test self-report questionnaires. It was hypothesized that both mindfulness groups would demonstrate significantly improved inhibition and shifting processing efficiencies compared to a mind wandering control, and that the mindful acceptance group would demonstrate significantly greater gains than the mindful physiological awareness group. Minimal differences in performance effectiveness were expected among all groups. Contrary to hypotheses, results indicated no significant effects of group on inhibition and shifting processing efficiencies or performance effectiveness in the anxious subsample. However, in the non-anxious subsample, the mindful acceptance group had shorter reaction times than the other two groups and the mindful physiological awareness group had higher accuracy rates than the control group. Findings suggest anxious individuals may need more extensive mindfulness practice to improve attentional control, as they tend to display greater attention deficits than non-anxious individuals. However, the study was limited in sample size and further research and study replication is needed prior to making conclusions about whether attentional control is a true mechanism of change. Study limitations, strengths, and future directions for study are also discussed.
276

In Vitro Catalytic Activity and Inhibition Study of PrnB from Burkholderia Ambifaria

Ge, Qi 11 August 2012 (has links)
PrnB is a heme-containing enzyme, which catalyzes the ring rearrangement reaction of 7-chlorotryptophan to produce 3-(3-Chloro-2-nitrophenyl)pyrrole. This thesis describes the initial isolation and characterization of PrnB, the second enzyme associated with the pyrrolnitrin biosynthetic pathway in Burkholderia ambifaria. Additionally, alternative peroxidase reactivity was used to study how amino-acids bind to the substrate binding pocket of PrnB. The peroxidase activity of PrnB was measured using three different peroxidase activity assays at various pH values. The peroxidase data was compared to similar studies with the classic peroxidase, Horseradish peroxidase (HRP). Generally, PrnB showed weak peroxidase reactivity. However this weak reactivity was an experimental handhold, where tryptophan and other substrate binding events can be explored using classic inhibition steady-state kinetics. The rate of 2-aminophenol oxidation by PrnB was used as a model assay to monitor how molecules such as L-tryptophan, L-alanine, indole, L-phenylalanine, and L-tyrosine interact with the PrnB active site.
277

Inhibitory control in adults with ADHD

Gard, Zoey January 2023 (has links)
Inhibitory control refers to a person’s ability to control responses and impulses. Deficits in inhibitory control have been found in the neurodevelopmental disorder of Attention deficit hyperactivity disorder (ADHD), though this has mainly been studied in children. This thesis is a systematic review of how inhibition is impacted in adults with ADHD and which neural correlates that are associated with inhibitory control. Only peer-reviewed original articles that used adults above the age of 18 were included. All articles used a between subject design, meaning healthy participants were compared to participants with ADHD. To measure inhibitory control, articles which used either the Stroop Task or Go/No-go task were examined. Nine articles were included in this systematic review. Through functional magnetic resonance imaging (fMRI) altered neural activation was seen in several brain regions, such as the dorsolateral prefrontal cortex, fronto-basal ganglia networks, anterior cingulate cortex, posterior cingulate cortex, parietal lobe and inferior frontal gyrus. Many of these regions have previously been linked to inhibitory control, while others hint at possible compensatory pathways for inhibition in ADHD. In summary, subtle impairments in inhibition networks appear to underlie the disorder all the way into adulthood.
278

Surface and active site modification of proteins with organometallic markers and inhibitors / Modifikation von Proteinen an der Oberfläche und im aktiven Zentrum durch organometallische Marker und Inhibitoren

Graf, Dominic January 2022 (has links) (PDF)
After implementing a reliable mass spectrometry based kinetic study the indole conjugation with different organometallic indoles led to questions about the electronical and sterical influences on reactivity. The substitution pattern of the ferrocene functionalized indoles at the six-membered ring determines the electron density on the C3 atom, which reacts with the formed Schiff base. Since the experimental results showed the exact opposite trend, covalent docking studies were performed elucidating the importance of surface interactions. These studies were in harmony with the experimental results and determined lysine 33 as most preferable conjugation site as well as substitution in 6-position as most favourable pattern. The amine motif in compounds 6, 7 and 8 proofed to be easily fragmented by the ESI method used. The amide linker in 10 remains intact but shows a lower conversion. Those two inherent characteristics are however preferable for well-defined and site-specific bioconjugation. The synthesis and evaluation of piano stool complex derivatives with manganese and rhenium metal centre 15, 16, 18 and 22 gave additional guidance by the interpretation of applicable structural motifs. The electron-withdrawing carbonyl groups lead to the hindrance of fulvene formation and thus to no fragmentation as seen with the ferrocene group. The total conversion is low compared to 8, only 22 shows a good enough conversion to mainly monoconjugate of 45% and a possible radio-labelling application as 99mTc analogue. As consequence manganese complexes with a stable facial tricarbonyl unit and a tridentate chelator with 4-, 5- and 6-substituted aminomethylindole conjugated through an amide bond were synthesized and consecutively evaluated. The resulting organometallic indole derivatives 29, 30 and 31 all showed a total conversion around 40% similar to 16, but at the same time a rate constant in the range of 10-4 s-1 like the organic indole. Besides the similar conversion, the rate constants followed the trend of the 6-substituted derivative as fastest and then 5- and 4- substituted derivative with decreasing reactivity. For underlining the usage as technetium label for the best out of the series 31, a rhenium analogue was prepared. The resulting compound 32 was especially interesting, because the conversion was even higher than the 70% of 8 with a total of 88%. Additionally, the rate constant was a tenfold higher as well. This rendered compound 32 as best possible 99mTc analogue for further application as radio-label. After the success of 32 and realizing the sterical benefits resulting from the flexible tridentate ligand-system, substitution at the five-membered ring was explored. The complexes 33, 34 and 35 are based on indole-2-carboxylic acid and with the difference of the length of the alkyl spacer between amide and complex to probe for the influence and sterical hindrance, but all three derivatives showed no conjugation which excludes functionalization in 2-position. As the C3 is used for the actual bioconjugation, the last possible derivatization was realized on the indole-N1 by using 1-(3-bromopropyl)indole as building block during the synthesis of the ligand-system. The corresponding manganese 36 and rhenium 37 complexes both showed similar properties of a moderate conversion like 22 and a rate constant in the range of 10-5 s-1. In conclusion the rhenium complex 32 with the 6-substitution pattern at the tridentate indole-bearing ligand remains the most promising structure. The here developed liquid chromatography coupled mass spectrometry-based assay for the determination of inhibitory activity of drug candidates against the 3CLpro of the sever acute respiratory syndrome coronavirus type 2 was successfully implemented and especially designed to give, due to the available absorption spectra and corresponding mass traces, further insight in the otherwise through fluorescence resonance energy transfer-based assays neglected influences on the inhibition results. Starting with a literature-known quinolone containing covalent inhibitor 42 an N1-methylated derivative 43 and their analogues 44 and 45 in which the benzoic acid was exchanged for ferrocene carboxylic acid were synthesized. The inhibition of 3CLpro was evaluated by the concentration of initial 15mer peptide left after incubation and for that purpose the for 280 nm defined molar attenuation coefficient of (26.41±0.59) L*mol-1*cm-1 determined and used. The results showed a reaction of DL dithiothreitol with the less stable benzoic acid esters leading to a moderate inhibitory effect. The methylation in N1-position showed an increase in stability. The methylated and with ferrocene carboxylic acid functionalized derivative showed a complete inhibition during the timeframe of the assay. In search of a fluorescent and therefore traceable inhibitor, 4 hydroxycoumarin was used to synthesize the analogue with benzoic acid 49 and ferrocene carboxylic acid 50. Both derivatives were less stable than their analogues but exhibited the same trend of a more stable ferrocene-derived compound, which exerted a higher inhibition as well. After preparing and testing the model thioester 53 and showing an inactivation of the established inhibitor ebselen, it was concluded that the reaction with DL dithiothreitol reduces the concentration of active intact inhibitor and therefore decreases the inhibition rate during the assay. The next step was proofing the reducing agent as non-essential for the fast assay conducted in a timeframe of 5 min to circumvent the negative influence of DL dithiothreitol. By excluding every inhibition-altering part, the resulting method is the perfect tool for precise statements in relation of inhibitory activity. Then the inhibition assay was repeated for ebselen and the best out of the here introduced organometallic inhibitors 45. Both give equivalent results of a complete inhibition during the measurement. The implemented liquid chromatography coupled mass spectrometry-based assay has many advantages over the fluorescence resonance energy transfer-based assays in which all the information and insight accumulated by the evaluation of uv/vis traces and mass spectra are not available leading to wrong or deviating results regarding the inhibitory capacity of inhibitor candidates. / Nach der erfolgreichen Implementierung einer auf Massenspektrometrie basierenden Methode, um kinetische Studien über die Indolkonjugation durchzuführen, kamen Fragen über die elektronischen und sterischen Einflüsse auf die Reaktivität auf. Das Substitutionsmuster der Ferrocen-funktionalisierten Indole am sechsgliedrigen Ring bestimmt die Elektronendichte am C3-Atom, welches wiederum mit der zuvor entstandenen Schiffbase reagiert. Da die experimentellen Daten einen der Elektronendichte entgegengesetzten Trend aufwiesen, wurden Docking-Studien durchgeführt, um die Einflüsse der Wechselwirkungen mit der Proteinoberfläche näher zu beleuchten. Diese entsprachen den experimentellen Werten und zeigten, dass Lysin 33 die bevorzugte Konjugationsstelle ist und dass die Substitution in 6-Position die energetisch günstigste darstellt. Das sekundäre Amin der Verbindungen 6, 7 und 8 wurde unter den ESI-Bedingungen leicht fragmentiert. Die Amid-Bindung von 10 dagegen bleibt intakt und ein langsamerer Umsatz, welcher für einen wohl definierten Umsatz sorgt, wurde beobachtet. Die Synthese und Evaluation der Halbsandwich-Komplexe 15, 16, 18 und 22 gab zusätzlichen Aufschluss über die strukturellen Einflüsse. Die elektronenziehenden Carbonyle behindern die Bildung der Fulvene, welche für die Ferrocen-Derivate beobachtet worden war. Der Gesamtumsatz ist vergleichsweise gering und nur Substanz 22 zeigt eine annehmbare Konversion von 45% an Monokonjugat auf, welches sie wiederum für den Einsatz als 99mTc-Analog qualifiziert. Als direkte Konsequenz wurden Mangankomplexe mit einer stabilen facialen Tricarbonyl-Einheit und einem Indol beinhaltenden tridentaten Liganden synthetisiert. Dies wurde für die 4-, 5- und 6-Substitution durchgeführt um die Komplexe 29, 30 und 31 zu erhalten. Alle drei zeigten eine Konversion von ungefähr 40% und lagen mit einer Ratenkonstante von 10-4 s-1 in dem Bereich des organischen Indols. Die Ratenkonstanten folgten hingegen wiederum dem Trend der begünstigten 6-Position, gefolgt von der 5- und dann 4-Position. Um einen Verglich zu einer analogen Technetium-Verbindung zu ziehen wurde der beste Komplex 31 als Rhenium-Analog 32 hergestellt. Dies wies den bisher höchsten Gesamtumsatz von 88% auf, welches die Konversion von 70% der Verbindung 8 überschritt. Dadurch qualifizierte sich Verbindung 32 als beste Option für eine Umsetzung als Radiomarker. Nach den Erkenntnissen über die begünstigte Sterik der flexiblen tridendaten Liganden wurde versucht den Erfolg auf den Fünfring zu übertragen. Eine auf Indol-2-säure basierende Reihe an Komplexen (33,34,35) mit unterschiedlich langen Alkyl-Ketten zwischen Indol und Metallkomplex sollte Aufschluss über den sterischen Anspruch geben, allerdings war keine Konjugation für alle drei Derivate zu beobachten. Als Konsequenz wurde die 2-Position für weitere Funktionalisierung nicht weiter berücksichtigt. Die letzte verbliebene Stelle war das Indol-amin selbst, welche durch den Einsatz von 1-(3-bromopropyl)indol bei der Ligandensynthese erfolgreich alkyliert wurde. Der resultierende Mangan- 36 und Rhenium-Komplex 37 zeigten eine mit 22 vergleichbare moderate Konversion und um eine Größenordnung kleinere Ratenkonstante. Durch diese Erkenntnisse verblieb der Rhenium-Komplex 32 weiterhin der beste Kandidat für eine Umsetzung als radioaktiver Marker. Der hier beschriebene liquid chromatography coupled mass spectrometry basierte Assay für die Bestimmung der Inhibitions-Wirkung gegenüber der 3CLpro des sever acute respiratory syndrome coronavirus type 2 wurde erfolgreich etabliert. Durch die zusätzlichen Absorptions , sowie Massenspektren wurden weitere Informationen gewonnen, welche in den oft angewendeten Fluoreszenz-Resonanzenergietransfer Assays vernachlässigt werden und zu Verfälschungen der Inhibitionsergebnisse führen. Ausgehend von dem literaturbekannten kovalenten Inhibitor 42 wurde ein N1-methyliertes Derivat 43 hergestellt. Durch den Austausch von Benzoesäure durch Ferrocensäure wurden die Analoge 44 und 45 erhalten. Die Restkonzentration des 15mer Substrats nach der Inkubation wurde als Maß der Inhibition herangezogen. Hierfür wurde der molare Extinktionskoeffizient bei 280 nm mit (26.41±0.59) L*mol-1*cm-1 bestimmt. Die Methylierung führte zu einer erhöhten Stabilität. Der Wirkstoffkandidat 45 zeigte außerdem eine vollständige Inhibition im Rahmen des durchgeführten Assays. 4-Hydroxycoumarin wurde verwendet, um die fluoreszenten Analoga 49 und 50 herzustellen. Beide waren instabiler, wobei das Ferrocen-Derivat wie zuvor eine erhöhte Inhibition aufzeigte. Nach der Synthese und Auswertung des Assays für eine Thioester Modellverbindung 53 und einer nachgewiesenen Inaktivierung des etablierten Inhibitors Ebselen wurden die Nebenreaktionen mit DL-Dithiothreitol als Ursache für einen Konzentrationsabfall der aktiven und intakten Inhibitoren und infolgedessen verringerte Inhibition angenommen. Als nächstes wurde bewiesen, dass der Zusatz eines Reduktionsmittels wie keinen Einfluss auf die Enzymaktivität während des kurzen Assays hat. So wurden alle Einflüsse auf die Inhibitionswirkung ausgeschlossen und der nun makellose Assay für Ebselen und den hier vorgestellten neuartigen organometallischen Inhibitor 45 wiederholt, welche beide eine vollständige Inhibition aufwiesen.
279

An Investigation into the Structure of Self-Control

Dreves, Parker A, Blackhart, Ginette 12 April 2019 (has links)
Self-control has been measured using a variety of methods including self-report measures, cognitive inhibition tasks, delay discounting and delay of gratification tasks, and persistence and willpower tasks. Although these are all theoretically linked to processes involved in self-control, recent evidence has shown that these diverse measurement techniques relate only minimally to one another. Assuming that self-control is a reflective construct, this would indicate that many of these tasks are poor indicators of self-control. The present research challenges the common assumption that self-control is a reflective construct and instead proposes that self-control is a formative construct. Conceptualizing of self-control as a formative construct could reconcile some of the inconsistencies in the literature, in particular the fact that many indicators for self-control do not correlate highly. To examine the possibility of a formative model of self-control, this research examines 13 commonly used measures of self-control and investigates indicator intercorrelations, indicator relationships with the theoretical consequences of self-control, and performs a vanishing tetrad test (Bollen & Ting, 2000). Results show that in general, indicator intercorrelations are low and nonsignificant as well as indictor correlations with theorized construct consequences. The results of the vanishing tetrad test suggest a reflective interpretation of self-control, but concerns with uniformly low covariances between indicators limit the interpretation of this test. It is concluded that currently available measures of self-control contain large sources of error variance and that questions about the ontological nature of the construct will be unanswerable until more precise measures are developed.
280

Veränderung der Tumorimmunumgebung muriner Mamma-Karzinome durch Inhibierung der Kollagensynthese / Alteration of the tumor immune environment in murine mamma carcinomas by inhibition of collagen synthesis

Höhn, Marie January 2023 (has links) (PDF)
Das Mamma-Karzinom gehört zu den sogenannten desmoplastischen Tumorarten. Hierbei handelt es sich um Tumoren mit erhöhter Ansammlung von Bindegewebszellen und einer Akkumulation von Extrazellulärer Matrix (EZM). Diese verdichtete EZM wirkt sowohl auf mechanischer als auch auf Signalweg-vermittelter Ebene als eine Barriere, welche die therapeutische Wirksamkeit erheblich vermindert. Einer der Hauptbestandteile der EZM ist Kollagen. Durch Anwendung von Präparaten, welche die Kollagensynthese und -reifung inhibieren, kann die rigide Struktur aufgelockert werden. Daraus ergibt sich eine verbesserte Versorgung mit Nährstoffen und eine verbesserte Infiltrationsmöglichkeit für Immunzellen. Dies ist für die Effizienz der Immuntherapie, welche sich in den letzten Jahren als vielversprechende Alternative zu den Grundsäulen der Krebstherapie entwickelt hat, unabdinglich. In der vorliegenden Arbeit wurden murine Mamma-Karzinome der 4T1-Linie nach Behandlung mit EZM-destabilisierenden Kollageninhibitoren auf ihre Immunumgebung hin untersucht. Verwendet wurden drei Wirkstoffe, welche an unterschiedlichen Punkten in die Kollagensynthese und -reifung eingreifen: βAPN als LOX(L)-Inhibitor, 1,4-DPCA als P4HA-Inhibitor und Minoxidil als LH-Inhibitor. Die Behandlung führte zu einem deutlichen Anstieg aller untersuchten Immunzellen und deutet somit auf eine verbesserte Infiltrationsmöglichkeit hin. Zudem wurde die Expression maligner Signalwege, wie die der Angiogenese, Hypoxie, Metastasierungsneigung, Invasivität und Immunsuppression, verringert und tumorsuppressive Immunantworten verstärkt. Die Kollageninhibition hatte zusätzlich ein verringertes Tumorwachstum und eine Reduktion der Blutgefäßdichte zufolge. Als Fazit gilt es festzuhalten, dass die Verwendung von Kollageninhibitoren in der Immuntherapie eine vielversprechende Option zur Verbesserung der Effizienz dieser Therapeutika darstellt. Diese Erkenntnis gilt es im Rahmen künftiger wissenschaftlicher Untersuchungen weiterzuentwickeln. / The mamma carcinoma is a desmoplastic tumor which shows an accumulation of fibrotic tissue and of extracellular matrix (ECM). This highly dense ECM acts as a physical and signaling-mediated barrier reducing the efficacy of various therapeutic approaches. One of the main components of the ECM is collagen. The rigid structure can be loosened by drugs which inhibit collagen synthesis and maturation. This potentially leads to improved infiltration with nutrients and a better access for immune cells. These are absolutely necessary for the effectiveness of the immune therapy that has been established as a promising alternative approach in the last years in addition to the classical cancer therapy options. In this dissertation murine mamma carcinomas of the 4T1-tumor cell line were treated with collagen inhibitors, with the aim to destabilize the rigid ECM and analyze following changes of the immune environment. The drugs, that were used, inhibit at different stages collagen synthesis and maturation: βAPN as a LOX(L)-inhibitor, 1,4-DPCA as a P4HA-inhibitor and Minoxidil as a LH-inhibitor. The treatment led to an accumulation of different kinds of immune cells which shows the improved infiltration. Furthermore, malignant pathways concerning angiogenesis, hypoxia, invasiveness, metastasis, and immunosuppression are reduced. Tumor suppressive immune responses are enhanced. Moreover, we could ascertain a reduced tumor growth and microvessel density after treatment. All in all, the tumors show, because of the changed quantity and constellation of immune cells, a stronger immune stimulating function. This embodies the promising potential of the usage of collagen inhibitors as an additional treatment to immune therapy to facilitate its efficacy, which has to be examined by further studies.

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