Publications by authors named "Peter Maas"

The activation of the growth hormone receptor (GHR) is a major determinant of body growth. Defective GHR signaling, as seen in human Laron dwarfism, resulted in low plasma IGF-1 concentrations and limited growth, but also marked absence in the development of breast cancer and type 2 diabetes. In vitro, we identified a small molecule (C#1) that inhibits the translation of GHR mRNA to receptor protein.

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In the search for new antitubercular compounds, we leveraged target-directed dynamic combinatorial chemistry (tdDCC) as an efficient hit-identification method. In tdDCC, the target selects its own binders from a dynamic library generated , reducing the number of compounds that require synthesis and evaluation. We combined a total of 12 hydrazides and six aldehydes to generate 72 structurally diverse -acylhydrazones.

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Tubulin tyrosine ligase 12 (TTLL12) is a promising target for therapeutic intervention since it has been implicated in tumour progression, the innate immune response to viral infection, ciliogenesis and abnormal cell division. It is the most mysterious of a fourteen-member TTL/TTLL family, since, although it is the topmost conserved in evolution, it does not have predicted enzymatic activities. TTLL12 seems to act as a pseudo-enzyme that modulates various processes indirectly.

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Pharmaceutical residues end up in surface waters, impacting drinking water sources and contaminating the aquatic ecosystem. Pharmacists can play a role in reducing pharmaceutical residues, yet this is often not addressed in pharmacy undergraduate education. Therefore, we developed the educational module "Reducing Pharmaceuticals in Water" for pharmacy students; this was integrated in our pharmacy simulation game for third year Master of Pharmacy students at the University of Groningen.

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Cancer cells make extensive use of the folate cycle to sustain increased anabolic metabolism. Multiple chemotherapeutic drugs interfere with the folate cycle, including methotrexate and 5-fluorouracil that are commonly applied for the treatment of leukemia and colorectal cancer (CRC), respectively. Despite high success rates, therapy-induced resistance causes relapse at later disease stages.

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Growth hormone (GH) and insulin-like growth factor-1 (IGF1) play an important role in mammalian development, cell proliferation and lifespan. Especially in cases of tumor growth there is an urgent need to control the GH/IGF1 axis. In this study we screened a 38,480-compound library, and in two consecutive rounds of analogues selection, we identified active lead compounds based on the following criteria: inhibition the GH receptor (GHR) activity and its downstream effectors Jak2 and STAT5, and inhibition of growth of breast and colon cancer cells.

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The quantification and identification of new plasmid-acquiring bacteria in representative mating conditions is critical to characterize the risk of horizontal gene transfer in the environment. This study aimed to quantify conjugation events resulting from manure application to soils and identify the transconjugants resulting from these events. Conjugation was quantified at multiple time points by plating and flow cytometry, and the transconjugants were recovered by fluorescence-activated cell sorting and identified by 16S rRNA sequencing.

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Plasmid-mediated dissemination of antibiotic resistance among fecal in natural ecosystems may contribute to the persistence of antibiotic resistance genes in anthropogenically impacted environments. Plasmid transfer frequencies measured under laboratory conditions might lead to overestimation of plasmid transfer potential in natural ecosystems. This study assessed differences in the conjugative transfer of an IncP-1 (pKJK5) plasmid to three natural strains carrying extended-spectrum beta-lactamases, by filter mating.

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Application of animal manure to soils results in the introduction of manure-derived bacteria and their antimicrobial resistance genes (ARGs) into soils. ResCap is a novel targeted-metagenomic approach that allows the detection of minority components of the resistome gene pool without the cost-prohibitive coverage depths and can provide a valuable tool to study the spread of antimicrobial resistance (AMR) in the environment. We used high-throughput sequencing and qPCR for 16S rRNA gene fragments as well as ResCap to explore the dynamics of bacteria, and ARGs introduced to soils and adjacent water ditches, both at community and individual scale, over a period of three weeks.

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Transformed epithelial cells can activate programs of epithelial plasticity and switch from a sessile, epithelial phenotype to a motile, mesenchymal phenotype. This process is linked to the acquisition of an invasive phenotype and the formation of distant metastases. The development of compounds that block the acquisition of an invasive phenotype or revert the invasive mesenchymal phenotype into a more differentiated epithelial phenotype represent a promising anticancer strategy.

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Manure application can spread antimicrobial resistance (AMR) from manure to soil and surface water. This study evaluated the role of the soil texture on the dynamics of antimicrobial resistance genes (ARGs) in soils and surrounding surface waters. Six dairy farms with distinct soil textures (clay, sand, and peat) were sampled at different time points after the application of manure, and three representative ARGs sul1, erm(B), and tet(W) were quantified with qPCR.

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In the last years, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) became an imaging technique which has the potential to characterize complex tumor tissue. The combination with other modalities and with standard histology techniques was achieved by the use of image registration methods and enhances analysis possibilities. We analyzed an oral squamous cell carcinoma with up to 162 consecutive sections with MALDI MSI, hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC) against CD31.

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Transcription factors have an important role in cancer but are difficult targets for the development of tumour therapies. These factors include the Ets family, and in this study Elk3 that is activated by Ras oncogene /Erk signalling, and is involved in angiogenesis, malignant progression and epithelial-mesenchymal type processes. We previously described the identification and in-vitro characterisation of an inhibitor of Ras / Erk activation of Elk3 that also affects microtubules, XRP44X.

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Predicting compound chemical stability is important because unstable compounds can lead to either false positive or to false negative conclusions in bioassays. Experimental data (COMDECOM) measured from DMSO/H2O solutions stored at 50 °C for 105 days were used to predicted stability by applying rule-embedded naïve Bayesian learning, based upon atom center fragment (ACF) features. To build the naïve Bayesian classifier, we derived ACF features from 9,746 compounds in the COMDECOM dataset.

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Background: The United States introduced human T-lymphotropic virus Type I (HTLV-I) screening of blood donors in 1988. The US military uses freshly collected blood products for life-threatening injuries when available stored blood components in theater have been exhausted or when these components are unsuccessful for resuscitation. These donors are screened after donation by the Department of Defense (DoD) retrospective testing program.

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Background: The Armed Services Blood Program (ASBP) provides the farthest-reaching blood supply in the world. This article provides statistics and a review of blood operations in support of combat casualty care during the last 10 years. It also outlines changes in blood doctrine in support of combat casualty care.

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The technological evolution of the 1990s in both combinatorial chemistry and high-throughput screening created the demand for rapid access to the compound deck to support the screening process. The common strategy within the pharmaceutical industry is to store the screening library in DMSO solution. Several studies have shown that a percentage of these compounds decompose in solution, varying from a few percent of the total to a substantial part of the library.

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BioDeNO(x), a novel technique to remove NO(x) from industrial flue gases, is based on absorption of gaseous nitric oxide into an aqueous Fe(II)EDTA(2-) solution, followed by the biological reduction of Fe(II)EDTA(2-) complexed NO to N(2). Besides NO reduction, high rate biological Fe(III)EDTA(-) reduction is a crucial factor for a succesful application of the BioDeNO(x) technology, as it determines the Fe(II)EDTA(2-) concentration in the scrubber liquor and thus the efficiency of NO removal from the gas phase. This paper investigates the mechanism and kinetics of biological Fe(III)EDTA(-) reduction by unadapted anaerobic methanogenic sludge and BioDeNO(x) reactor mixed liquor.

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Biological reduction of nitric oxide (NO) to di-nitrogen (N(2)) gas in aqueous Fe(II)EDTA(2-) solutions is a key reaction in BioDeNOx, a novel process for NOx removal from flue gases. The mechanism and kinetics of the first step of NO reduction, that is, the conversion of NO to N(2)O, was determined in batch experiments using various types of inocula. Experiments were performed in Fe(II)EDTA(2-) medium (5-25 mM) under BioDeNOx reactor conditions (55 degrees C, pH 7.

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The stimulating effect of copper addition on the reduction rate of nitrous oxide (N(2)O) to dinitrogen (N(2)) in the presence of sulfide was investigated in batch experiments (pH 7.0; 55 degrees C). N(2)O was dosed either directly as a gas to the headspace of the bottles or formed as intermediate during the denitrification of nitrite in Fe(II)EDTA(2-)-containing medium and nitrate in Fe(II)EDTA(2-)-free medium.

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BioDeNOx is a novel technique for NOx removal from industrial flue gases. In principle, BioDeNOx is based on NO absorption into an aqueous Fe(II)EDTA2- solution combined with biological regeneration of that scrubber liquor in a bioreactor. The technical and economical feasibility of the BioDeNOx concept is strongly determined by high rate biological regeneration of the aqueous Fe(II)EDTA2- scrubber liquor and by EDTA degradation.

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Biological reduction of nitric oxide (NO) in aqueous solutions of EDTA chelated Fe(II) is one of the main steps in the BioDeNOx process, a novel bioprocess for the removal of nitrogen oxides (NOx) from polluted gas streams. Since NOx contaminated gases usually also contain sulfurous pollutants, the possible interferences of these sulfur compounds with the BioDeNOx process need to be identified. Therefore, the effect of the sulfur compounds Na2SO4, Na2SO3, and H2S on the biological NO reduction in aqueous solutions of Fe(II)EDTA2- (25 mM, pH 7.

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Reduction of EDTA-chelated Fe(III) is one of the core processes in the BioDeNOx process, a chemically enhanced technique for biological NOx removal from industrial flue gases. The capacity of Escherichia coli, three mixed cultures from full scale methanogenic granular sludge reactors, one denitrifying sludge, and a BioDeNOx sludge to reduce Fe(III)EDTA- (25 mM) was determined at 37 and 55 degrees C using batch experiments. Addition of catalytic amounts of sulfide greatly accelerated Fe(III)EDTA- reduction, indicating that biological Fe(III)EDTA- reduction is not a direct, enzymatic conversion but an indirect reduction with involvement of an electron-mediating compound, presumably polysulfides.

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An integrated physicochemical and biological technique for NO(x) removal from flue gas, the so-called BioDeNO(x) process, combines the principles of wet absorption of NO in an aqueous Fe(II)EDTA(2-) solution with biological reduction of the sorbed NO in a bioreactor. The biological reduction of NO to di-nitrogen gas (N(2)) takes place under thermophilic conditions (55 degrees C). This study demonstrates the technical feasibility of this BioDeNO(x) concept in a bench-scale installation with a continuous flue gas flow of 650 l.

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The reduction of nitric oxide (NO) in aqueous solutions of Fe(II)EDTA is one of the core processes in BioDeNOx, an integrated physicochemical and biological technique for NO(x)() removal from industrial flue gases. NO reduction in aqueous solutions of Fe(II)EDTA (20-25 mM, pH 7.2 +/- 0.

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