Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
LanguageLanguage
-
SubjectSubject
-
Item TypeItem Type
-
DisciplineDiscipline
-
YearFrom:-To:
-
More FiltersMore FiltersIs Peer Reviewed
Done
Filters
Reset
11
result(s) for
"Decker, Tanja"
Sort by:
The clinical-chemical screen in the Munich ENU Mouse Mutagenesis Project: screening for clinically relevant phenotypes
by
Fella, Christiane
,
Heffner, Stephan
,
Wolf, Eckhard
in
Animals
,
Biomarkers - blood
,
Biomarkers - urine
2000
The Munich ENU Mouse Mutagenesis Project within the German Human Genome Project is a phenotype-driven approach to produce, identify, and characterize new mouse mutants (Hrabe de Angelis and Balling 1998). The focus of the clinical-chemical screen is on laboratory diagnostic procedures (mainly bloodbased) suitable to detect hematological changes, defects of various organ systems, and changes in metabolic pathways and electrolyte homeostasis. The methods used are appropriate routine procedures, allowing the screening of large numbers of mice for a broad spectrum of clinical-chemical and hematological parameters. Since most inherited metabolic disorders in humans are known to lead directly or indirectly via altered organ function to changes in the parameters investigated (Fernandes et al. 1995; Saudubray and Charpentier 1995), this screen provides a comprehensive investigation of clinical phenotypes with known counterparts in humans.
Journal Article
Identification of immunological relevant phenotypes in ENU mutagenized mice
2000
The immunology screen focuses on the identification of novel gene products involved in the mammalian immune response and on the establishment of mouse models for immunological disorders. For this purpose, high throughput and semi-automated techniques were developed and optimized for low cost per sample and reproducibility. All assays are designed to be nonconsumptive and are based on peripheral blood or direct PCR amplification.
Journal Article
Multiplex secretome engineering enhances recombinant protein production and purity
2020
Host cell proteins (HCPs) are process-related impurities generated during biotherapeutic protein production. HCPs can be problematic if they pose a significant metabolic demand, degrade product quality, or contaminate the final product. Here, we present an effort to create a “clean” Chinese hamster ovary (CHO) cell by disrupting multiple genes to eliminate HCPs. Using a model of CHO cell protein secretion, we predict that the elimination of unnecessary HCPs could have a non-negligible impact on protein production. We analyze the HCP content of 6-protein, 11-protein, and 14-protein knockout clones. These cell lines exhibit a substantial reduction in total HCP content (40%-70%). We also observe higher productivity and improved growth characteristics in specific clones. The reduced HCP content facilitates purification of a monoclonal antibody. Thus, substantial improvements can be made in protein titer and purity through large-scale HCP deletion, providing an avenue to increased quality and affordability of high-value biopharmaceuticals.
Host cell proteins can contaminate biotherapeutics and compromise and degrade their quality. Here the authors use modelling and CRISPR to delete secreted host proteins in CHO cells, leading to improved monoclonal antibody production and purity.
Journal Article
Bacteria from the Amycolatopsis genus associated with a toxic bird secrete protective secondary metabolites
2024
Uropygial gland secretions of birds consist of host and bacteria derived compounds and play a major sanitary and feather-protective role. Here we report on our microbiome studies of the New Guinean toxic bird
Pachycephala schlegelii
and the isolation of a member of the
Amycolatopsis
genus from the uropygial gland secretions. Bioactivity studies in combination with co-cultures, MALDI imaging and HR-MS/MS-based network analyses unveil the basis of its activity against keratinolytic bacteria and fungal skin pathogens. We trace the protective antimicrobial activity of
Amycolatopsis
sp. PS_44_ISF1 to the production of rifamycin congeners, ciromicin A and of two yet unreported compound families. We perform NMR and HR-MS/MS studies to determine the relative structures of six members belonging to a yet unreported lipopeptide family of pachycephalamides and of one representative of the demiguisins, a new hexapeptide family. We then use a combination of phylogenomic, transcriptomic and knock-out studies to identify the underlying biosynthetic gene clusters responsible for the production of pachycephalamides and demiguisins. Our metabolomics data allow us to map molecular ion features of the identified metabolites in extracts of
P. schlegelii
feathers, verifying their presence in the ecological setting where they exert their presumed active role for hosts. Our study shows that members of the Actinomycetota may play a role in avian feather protection.
The microbiome in the uropygial gland and feathers of the bird
Pachycephala schlegii
has protective properties. Here, the authors report an
Amycolatopsis
species in this microbiome that produces antimicrobials including two novel compound families.
Journal Article
Phase II study of metronomic treatment with daily oral vinorelbine as first-line chemotherapy in patients with advanced/metastatic HR+/HER2− breast cancer resistant to endocrine therapy: VinoMetro—AGO-B-046
2021
PurposeMetronomic chemotherapy (MCT) is an increasingly used treatment option in hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2−) advanced/metastatic breast cancer (MBC) after failure of endocrine-based therapies.MethodsVinoMetro was a multicentre, open-label, single-arm, phase II study of metronomic oral vinorelbine (VRL; 30 mg/day) as a first-line chemotherapy (CT) in patients with HR+/HER2− MBC after endocrine failure. The primary endpoint was the clinical benefit rate (CBR) at 24 weeks.ResultsBetween January 2017 and April 2019, nine patients were enrolled. The CBR was 22.2% (90% confidence interval [CI] 4.1–55.0), p = 0.211. The median progression-free survival (PFS) was 12.0 weeks (95% CI 11.3–12.7). Grade 3–4 adverse events (AEs) occurred in 22.2% of patients. One patient died of febrile neutropenia.ConclusionVinoMetro (AGO-B-046) was closed early after nine patients and occurrence of one grade 5 toxicity in agreement with the lead institutional review board (IRB). Metronomic dosing of oral VRL in HR+/HER2− MBC as first-line CT after failure of endocrine therapies showed only limited benefit in this population.Trial registration number and date of registrationClinicalTrials.gov Identifier: NCT03007992; December 15, 2016.
Journal Article
A randomized phase II study of paclitaxel alone versus paclitaxel plus sorafenib in second- and third-line treatment of patients with HER2-negative metastatic breast cancer (PASO)
2017
Background
We conducted an open-label, randomized, two-arm multi-center study to assess the efficacy and safety of paclitaxel versus paclitaxel + sorafenib in patients with locally advanced or metastatic HER2-negative breast cancer.
Methods
Patients were randomly assigned to receive either paclitaxel monotherapy (80 mg/m
2
) weekly (3 weeks on, 1 week off) plus sorafenib 400 mg orally, twice a day taken continuously throughout 28 day cycles. Sorafenib dose was gradually escalated from a starting dose of 200 mg twice a day. The primary endpoint was progression free survival (PFS).
Results
A pre-planned efficacy interim analysis was performed on the data of 60 patients, 30 patients in each treatment arm. Median PFS was estimated at 6.6 months (95% CI: 5.1 to 9.0) in patients randomized to single-agent paclitaxel (Arm A) and 5.6 months (95% CI: 3.8 to 6.5) in patients randomized to paclitaxel-sorafenib combination (Arm B) therapy. Contrary to the hypothesis, the treatment effect was statistically significant in favor of paclitaxel monotherapy (hazard ratio 1.80, 95% CI: 1.02 to 3.20; log-rank test
P
= 0.0409). It was decided to stop the trial early for futility. Median OS was also in favor of Arm A (20.7 months (95% CI: 16.4 to 26.7) versus 12.1 months (95% CI: 5.8 to 20.4) in Arm B. Clinical control was achieved in 28 patients (93.3%) in Arm A and in 21 patients 70.0% in Arm B. Overall response rate was met in 43.3% of patients in Arm A and in 40.0% in Arm B. Toxicities were increased in Arm B with higher rates of diarrhea, nausea, neutropenia, hand-foot skin reaction (HFSR) and anorexia, Grad 3 and 4 toxicities were rare.
Conclusions
In this pre-planned interim analysis, paclitaxel-sorafenib combination therapy was not found to be superior to paclitaxel monotherapy with regard to the primary end point, progression-free survival. The trial was therefore discontinued early. There was no indication of more favorable outcomes for combination therapy in secondary efficacy end points. As expected, the safety and toxicity profile of the combination therapy was less favorable compared to monotherapy. Overall, this trial did not demonstrate that adding sorafenib to second- or third-line paclitaxel provides any clinical benefit to patients with HER2-negative advanced or metastatic breast cancer. Cautious dosing using a sorafenib ramp up schedule might have contributed to negative results.
Trial registration
The study was registered at EudraCT (No 2009–018025-73) and retrospectively registered at Clinical trials.gov on March 17, 2011 (
NCT01320111
).
Journal Article
Intracellular bacteria engage a STING–TBK1–MVB12b pathway to enable paracrine cGAS–STING signalling
2019
The innate immune system is crucial for eventual control of infections, but may also contribute to pathology.
Listeria monocytogenes
is an intracellular Gram-positive bacteria and a major cause of food-borne disease. However, important knowledge on the interactions between
L. monocytogenes
and the immune system is still missing. Here, we report that
Listeria
DNA is sorted into extracellular vesicles (EVs) in infected cells and delivered to bystander cells to stimulate the cyclic guanosine monophosphate–adenosine monophosphate synthase (cGAS)–stimulator of interferon genes (STING) pathway. This was also observed during infections with
Francisella tularensis
and
Legionella pneumophila
. We identify the multivesicular body protein MVB12b as a target for TANK-binding kinase 1 phosphorylation, which is essential for the sorting of DNA into EVs and stimulation of bystander cells. EVs from
Listeria
-infected cells inhibited T-cell proliferation, and primed T cells for apoptosis. Collectively, we describe a pathway for EV-mediated delivery of foreign DNA to bystander cells, and suggest that intracellular bacteria exploit this pathway to impair antibacterial defence.
Bacterial DNA from
Listeria monocytogenes
infection is packaged within extracellular vesicles and induces paracrine cGAS–STING signalling in bystander cells to subvert host responses.
Journal Article
Influence of Moisturizers on Skin Microcirculation: An Assessment Study Using Laser Speckle Contrast Imaging
2023
Non-invasive scar management typically involves pressure therapy, hydration with silicones or moisturizers, and UV protection. Moisture loss from scars can lead to hypertrophic scar formation. Pressure therapy reduces blood flow, fibroblast activity, and transforming growth factor beta 1 (TGF-β1) release. This study examined various moisturizers and liquid silicone gel’s impact on microcirculation. 40 volunteers participated in a study where superficial abrasions were created to induce trans epidermal water loss (TEWL). Five moisturizers (TEDRA®, TEDRA® NT1, TEDRA® NT3, Alhydran®, Lipikar®) and BAP Scar Care® silicone gel were tested. TEWL, hydration, and blood flow were measured up to 4 h post-application. Results showed that silicone had the least impact on occlusion and hydration. Alhydran® reduced blood flow the most, while Lipikar® increased it the most. TEDRA® NT1 had reduced flow compared to TEDRA® and TEDRA® NT3. All TEDRA® products exhibited high hydration, and all but silicone showed good occlusion. Moisturizers influenced skin microcirculation, with some causing decrease, while others increased flow. However, the clinical impact on scarring remains unclear compared to the evident effects of hydration and occlusion. More research is necessary to study moisturizers alone and with pressure therapy on scars, along with potential adverse effects of increased microcirculation on scars.
Journal Article
Regulation of the arachidonic acid mobilization in macrophages by combustion-derived particles
by
Paur, Hanns-Rudolf
,
Diabaté, Silvia
,
Mülhopt, Sonja
in
Air Pollutants - analysis
,
Air Pollutants - toxicity
,
Animals
2011
Background
Acute exposure to elevated levels of environmental particulate matter (PM) is associated with increasing morbidity and mortality rates. These adverse health effects, e.g. culminating in respiratory and cardiovascular diseases, have been demonstrated by a multitude of epidemiological studies. However, the underlying mechanisms relevant for toxicity are not completely understood. Especially the role of particle-induced reactive oxygen species (ROS), oxidative stress and inflammatory responses is of particular interest.
In this
in vitro
study we examined the influence of particle-generated ROS on signalling pathways leading to activation of the arachidonic acid (AA) cascade. Incinerator fly ash particles (MAF02) were used as a model for real-life combustion-derived particulate matter. As macrophages, besides epithelial cells, are the major targets of particle actions in the lung murine RAW264.7 macrophages and primary human macrophages were investigated.
Results
The interaction of fly ash particles with macrophages induced both the generation of ROS and as part of the cellular inflammatory responses a dose- and time-dependent increase of free AA, prostaglandin E
2
/thromboxane B
2
(PGE
2
/TXB
2
), and 8-isoprostane, a non-enzymatically formed oxidation product of AA. Additionally, increased phosphorylation of the mitogen-activated protein kinases (MAPK) JNK1/2, p38 and ERK1/2 was observed, the latter of which was shown to be involved in MAF02-generated AA mobilization and phosphorylation of the cytosolic phospolipase A
2
. Using specific inhibitors for the different phospolipase A
2
isoforms the MAF02-induced AA liberation was shown to be dependent on the cytosolic phospholipase A
2
, but not on the secretory and calcium-independent phospholipase A
2
. The initiation of the AA pathway due to MAF02 particle exposure was demonstrated to depend on the formation of ROS since the presence of the antioxidant N-acetyl-cysteine (NAC) prevented the MAF02-mediated enhancement of free AA, the subsequent conversion to PGE
2
/TXB
2
via the induction of COX-2 and the ERK1/2 and JNK1/2 phosphorylation. Finally we showed that the particle-induced formation of ROS, liberation of AA and PGE
2
/TXB
2
together with the phosphorylation of ERK1/2 and JNK1/2 proteins was decreased after pre-treatment of macrophages with the metal chelator deferoxamine mesylate (DFO).
Conclusions
These results indicate that one of the primary mechanism initiating inflammatory processes by incinerator fly ash particles seems to be the metal-mediated generation of ROS, which triggers via the MAPK cascade the activation of AA signalling pathway.
Journal Article