Biology subjects

Buch, T.

Publications and source records attributed to Buch, T..

4 recordsLinked to original sources

bioRxiv2026

Standardisation Challenges in ELISA-Based Quantification of Equine Chorionic Gonadotropin (eCG/PMSG)

Equine chorionic gonadotropin (eCG/PMSG) is widely used for female-cycle synchronization and estrus induction in livestock and in biomedical research, where reliable quantitative assessment is increasingly important. However, its structural and glycosylation heterogeneity complicates antibody-based measurement and assay standardization. This Technical Note evaluated six commercially available quantitative PMSG ELISA kits representing three distinct analytical profile groups. Kit-provided calibration standards were characterized by Western blotting, Coomassie staining, and LC-MS/MS, while quantitative performance was assessed using serial dilutions of two commercial PMSG preparations. DRG, Creative Diagnostics, and Demeditec showed similar calibration-standard profiles and concentration-dependent responses, although measured concentrations were consistently below nominal values. Biomatik and MyBiosource displayed closely related analytical profiles but little meaningful concentration-dependent response, whereas Krishgen measurements remained within a narrow range despite changes in nominal PMSG input. The calibration standards differed substantially in protein composition, and no eCG-derived peptides were identified by LC-MS/MS under the conditions used. These findings demonstrate that quantitative results obtained with commercially available PMSG ELISAs are not necessarily comparable and may be strongly influenced by calibration-material composition, assay format, and matrix effects. The findings highlight the limitations of current quantitative PMSG assays and the need for a well-characterized, commutable reference material, together with assay-specific validation of dilution parallelism and analyte recovery, to improve the reliability and comparability of eCG/PMSG measurements.

biochemistry↗

bioRxiv2023

Refined Tamoxifen Administration in Mice by Encouraging Voluntary Consumption of Palatable Formulations.

Drug administration in preclinical rodent models is essential for research and development of novel therapies. Compassionate administration methods have been developed, but these are mostly incompatible with water-insoluble drugs such as tamoxifen or do not allow for precise timing or dosing of the drugs. For more than two decades, tamoxifen has been administered by oral gavage or injection to CreERT2/loxP gene-modified mouse models to spatiotemporally control gene expression, with the numbers of such models steadily increasing in recent years. Animal-friendly procedures for accurately administering tamoxifen or other water-insoluble drugs would therefore have an important impact on animal welfare. Based on a previously published micropipette feeding protocol, we developed palatable formulations to encourage voluntary consumption of tamoxifen. We evaluated the acceptance of the new formulations by mice during training and treatment and assessed the efficacy of tamoxifen-mediated induction of CreERT2/loxP dependent reporter genes. Both sweetened milk and syrup-based formulations encouraged mice to consume tamoxifen voluntarily, but only sweetened milk formulations were statistically non-inferior to oral gavage in inducing CreERT2-mediated gene expression. Serum concentrations of tamoxifen metabolites, quantified using an in-house developed cell assay, confirmed the lower efficacies of syrup- as compared to sweetened milk-based formulations. We found dosing with a micropipette to be more accurate, with the added advantage that the method requires little training for the experimenter. The new palatable solutions encourage voluntary consumption of tamoxifen without loss of efficacy compared to oral gavage and thus represent a refined administration method.

animal behavior and cognition↗

bioRxiv2021

Group size planning of breedings of gene-modified animals

Animal breeding is time-consuming, costly, and affected by stochastic events related to Mendelian genetics, fertility, and litter size. Careful planning is mandatory to ensure a successful outcome using the least number of animals, hence adhering to the 3Rs of animal welfare. We have developed an R package, accessible also through an interactive website, that optimizes breeding design and provides a comprehensive report suitable for any breeder of genetically defined traits.

bioinformatics↗

bioRxiv2021

TGF-β1 drives Th9 but not Treg cells upon allergen exposure

TGF-{beta}1 is known to have a pro-inflammatory impact by inducing Th9 cells, while it also induces anti-inflammatory Treg cells (Tregs). In the context of allergic airway inflammation (AAI) its dual role can be of critical importance in influencing the outcome of the disease. Here we demonstrate that TGF-{beta} acts in AAI by driving effector T cells into Th9 cells, while Tregs differentiate independently. Induction of experimental AAI and airway hyperreactivity in a mouse model with inducible genetic ablation of the TGF{beta}-receptor 2 (TGFBR2) on CD4+T cells significantly reduced the disease phenotype. Further, it blocked the induction of Th9 cell frequencies, but increased Treg cells. To translate these findings into a human clinically relevant context, Th9 and Treg cells were quantified both locally in induced sputum and systemically in blood of allergic rhinitis and asthma patients with or without allergen-specific immunotherapy (AIT). Natural allergen exposure induced local and systemic Th2, Th9 cell and reduced Tregs, while therapeutic allergen exposure by AIT suppressed Th2 and Th9 cell frequencies along with TGF-{beta} and IL-9 secretion. Altogether, these findings support that neutralization of TGF-{beta} represents a viable therapeutic option in allergy and asthma, not posing the risk of immune dysregulation by impacting Tregs.

immunology↗