Nele Fritsch

Mrs. Nele Fritsch

Chemical and Product Safety, Federal Institute for Risk Assessment, Berlin, Germany
orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 March 2020 in Polymers
Verified
Journal Article
Open access
PDF file
HRHenrike Rebl
Henrike Rebl
JRJuergen Renner
Juergen Renner
WKWolfgang Kram
Wolfgang Kram
ASArmin Springer
Armin Springer
NFNele Fritsch
Nele Fritsch
J. Barbara NebeJ. Barbara Nebe
J. Barbara Nebe
Encrustations of ureteral stents are one of the biggest problems with urological implants. Crystalline biofilms can occur alone or in combination with bacterial biofilms. To identify which surface parameters provide guidance for the development of novel stent materials, we used an in vitro encrustation system. Synthetic urine with increasing pH to simulate an infection situation was pumped over the polymer samples with adjusted flow rates at 37 °C to mimic the native body urine flow. Chemical surface features (contact angle, surface charge), as well as encrustations were characterized. The encrustations on the materials were analyzed quantitatively (dry mass) and qualitatively using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The aim of this comparative study was to identify crucial surface parameters that might predict the quantity and type of mineral deposits in vitro and provide guidance for the development and screening of new polymer-based biomaterials for ureteral stent design. For the first time, we could identify that, within the range of our polymers, those materials with a slight hydrophilicity and a strong negative zeta potential (around −60 mV) were most favorable for use as ureteral stent materials, as the deposition of crystalline biofilms was minimized.

29 September 2022 in Cells
Verified
Journal Article
Open access
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Kerstin JurkKerstin Jurk
Kerstin Jurk
AAAnke Adenaeuer
Anke Adenaeuer
SSStefanie Sollfrank
Stefanie Sollfrank
KGKathrin Groß
Kathrin Groß
FHFriederike Häuser
Friederike Häuser
FBFrauke Bergmann
Frauke Bergmann
Germline defects in the transcription factor GATA1 are known to cause dyserythropoiesis with(out) anemia and variable abnormalities in platelet count and function. However, damaging variants closely located to the C-terminal zinc finger domain of GATA1 are nearly unknown. In this study, a 36-year-old male index patient and his 4-year-old daughter suffered from moderate mucocutaneous bleeding diathesis since birth. Whole exome sequencing detected a novel hemizygous GATA1 missense variant, c.886A>C p.T296P, located between the C-terminal zinc finger and the nuclear localization sequence with non-random X-chromosome inactivation in the heterozygous daughter. Blood smears from both patients demonstrated large platelet fractions and moderate thrombocytopenia in the index. Flow cytometry and electron microscopy analysis supported a combined α-/δ (AN-subtype)-storage pool deficiency as cause for impaired agonist-induced platelet aggregation (light transmission aggregometry) and granule exocytosis (flow cytometry). The absence of BCAM in the index (Lu(a-b-)) and its low expression in the daughter (Lu(a-b+)) confirmed a less obvious effect of defective GATA1 also on erythrocytes. Borderline anemia, elevated HbF levels, and differential transcription of GATA1-regulated genes indicated mild dyserythropoiesis in both patients. Furthermore, a mild SLC4A1 defect associated with a heterozygous SLC4A1 c.2210C>T p.A737V variant maternally transmitted in the daughter may modify the disease to mild spherocytosis and hemolysis.

1 November 2020 in Mendeleev Communications
Verified
Journal Article
Closed access
ENEvgenia V. Nurieva
Evgenia V. Nurieva
NZNikolay A. Zefirov
Nikolay A. Zefirov
NFNele Fritsch
Nele Fritsch
Elena R. MilaevaElena R. Milaeva
Elena R. Milaeva
SKSergei A. Kuznetsov
Sergei A. Kuznetsov
OZOlga N. Zefirova
Olga N. Zefirova
Two new heterobivalent molecules were designed by linking a DNA-alkylating agent chlorambucil with tubulin-targeting compound colchicine or its adamantyl containing C(7)-derivative. Target compounds were synthesized via acid coupling with N-deacetylcolchicine. According to preliminary biotests, both conjugates caused microtubule depolymerization and strong tubulin clustering, and colchicine–chlorambucil conjugate was found to be one order of magnitude more potent and to exhibit some selectivity to A549 carcinoma cells.

6 November 2024 in Toxics
Verified
Journal Article
Open access
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NFNele Fritsch
Nele Fritsch
MAMarina Aparicio-Soto
Marina Aparicio-Soto
CCCaterina Curato
Caterina Curato
FRFranziska Riedel
Franziska Riedel
HTHermann-Josef Thierse
Hermann-Josef Thierse
Katherina SiewertKatherina Siewert
Katherina Siewert
T cell activation is the final key event (KE4) in the adverse outcome pathway (AOP) of skin sensitization. However, validated new approach methodologies (NAMs) for evaluating this step are missing. Accordingly, chemicals that activate an unusually high frequency of T cells, as does the most prevalent metal allergen nickel, are not yet identified in a regulatory context. T cell reactivity to chemical sensitizers might be especially relevant in real-life scenarios, where skin injury, co-exposure to irritants in chemical mixtures, or infections may trigger the heterologous innate immune stimulation necessary to induce adaptive T cell responses. Additionally, cross-reactivity, which underlies cross-allergies, can only be assessed by T cell tests. To date, several experimental T cell tests are available that use primary naïve and memory CD4+ and CD8+ T cells from human blood. These include priming and lymphocyte proliferation tests and, most recently, activation-induced marker (AIM) assays. All approaches are challenged by chemical-mediated toxicity, inefficient or unknown generation of T cell epitopes, and a low throughput. Here, we summarize solutions and strategies to confirm in vitro T cell signals. Broader application and standardization are necessary to possibly define chemical applicability domains and to strengthen the role of T cell tests in regulatory risk assessment.

28 February 2025 in Toxicology
Verified
Journal Article
Open access
SSStefanie Seifert
Stefanie Seifert
Katherina SiewertKatherina Siewert
Katherina Siewert
CCCaterina Curato
Caterina Curato
ASAnna Sonnenburg
Anna Sonnenburg
NFNele Fritsch
Nele Fritsch
DBDenise Bloch
Denise Bloch
According to Regulation (EC) No 1272/2008, plant protection products (PPPs) can be classified for skin sensitisation by either considering the full formulation or the individual components. For a fraction of PPPs, an application of both assessment strategies results in discrepant classification results. We here aimed to resolve this discrepancy for PPP 1, an exemplary product, which was classified as sensitizing by a positive local lymph node assay but scored negative by the component-based method. We collected further data, as suggested by the regulation, based on a combination of new approach methodologies (NAMs) covering several key events (KEs) in the adverse outcome pathway model for skin sensitisation. Precisely, we employed quantitative structure activity relationship (QSAR) analysis (KE 1), the human cell line activation test (h-CLAT) complemented by Interleukin-8 release measurements (KE 3) and a novel short-term T cell test that is based on the induced expression of activation markers (KE 4). We tested the complete product, individual co-formulants (CFs) or single substances. PPP 1 tested positive in all in vitro assays. QSAR analysis revealed two CFs containing sensitizing chemicals. Only CF 1 was tested positive in the h-CLAT at a minimal induction threshold of 1.5 mg/mL, being less potent than PPP 1. In the T cell assay, both PPP 1 and CF 1 were tested positive at around 0.1 mg/mL. In conclusion, our results propose a novel integrated NAM-based strategy that should be explored further for skin sensitisation hazard identification of complex mixtures, such as PPPs.