Publications by authors named "Michael Visser"

Uveal melanoma (UM) is the most common primary intraocular malignancy in the adult eye. Despite the aggressive local management of primary UM, the development of metastases is common with no effective treatment options for metastatic disease. Genetic analysis of UM samples reveals the presence of mutually exclusive activating mutations in the Gq alpha subunits GNAQ and GNA11.

View Article and Find Full Text PDF
Article Synopsis
  • Malignant tumors can avoid the immune system's attacks by luring in regulatory T cells (Treg), and the IKZF2 (Helios) transcription factor is essential for Treg cell stability and function.
  • The study introduces NVP-DKY709, a new drug that specifically targets and degrades IKZF2 while leaving other related factors (IKZF1/3) intact, enhancing the immune response against tumors.
  • In tests, NVP-DKY709 not only improved the activity of T-effector cells and reduced tumor growth in mice but is also being explored for its potential as a cancer treatment in clinical trials.
View Article and Find Full Text PDF

The human gut microbiome plays a central role in health and disease. Environmental factors, such as lifestyle and diet, are known to shape the gut microbiome as well as the reservoir of resistance genes that these microbes harbour; the resistome. In this study we assessed whether long-term dietary habits within a single geographical region (the Netherlands) impact the human gut resistome.

View Article and Find Full Text PDF

Genome sequences provide information on the genetic elements present in an organism, and currently there are databases containing hundreds of thousands of bacterial genome sequences. These repositories allow for mining patterns concerning antibiotic resistance gene occurrence in both pathogenic and non-pathogenic bacteria in e.g.

View Article and Find Full Text PDF

A syngas-degrading enrichment culture, culture T-Syn, was dominated by a bacterium closely related to strain AB33 (98% 16S rRNA gene sequence identity). Culture T-Syn could convert high CO concentrations (from pCO ≈ 34 kPa to pCO ≈ 170 kPa), both in the absence and in the presence of sulfate as external electron acceptor. The products formed from CO conversion were H and acetate.

View Article and Find Full Text PDF
Article Synopsis
  • Tomato brown rugose fruit virus (ToBRFV) is a new virus affecting tomato and pepper crops, first identified in Israel and Jordan around 2014-2015.
  • The virus has spread globally, with significant outbreaks detected in the Netherlands, leading to an investigation of its presence across various companies.
  • The research utilized Nextstrain to analyze and visualize the genetic diversity of ToBRFV genomes, revealing three main genetic clusters without a clear link to specific sources or companies, while encouraging data sharing for better understanding of the virus's spread.
View Article and Find Full Text PDF

Background: ESBL and AmpC β-lactamases are an increasing concern for public health. Studies suggest that ESBL/pAmpC-producing Escherichia coli and their plasmids carrying antibiotic resistance genes can spread from broilers to humans working or living on broiler farms. These studies used traditional typing methods, which may not have provided sufficient resolution to reliably assess the relatedness of these isolates.

View Article and Find Full Text PDF

The use of DNA demethylating agents has been popular in epigenetic studies. Recently, Cook and colleagues, in a 2015 article, claimed an effect of 5-aza-2'-deoxycytidine (5-aza-dC) on the sex ratio of a parasitoid wasp without verifying its effect on DNA methylation. We repeated the 5-aza-dC feeding treatment to test its effectiveness.

View Article and Find Full Text PDF
Article Synopsis
  • SMARCA2 (BRM) is a key ATPase and member of the SWI/SNF chromatin-remodeling complex, which plays a crucial role in regulating gene expression alongside its relative, BRG1 (SMARCA4).
  • Current research highlights the lack of small molecules that can specifically inhibit the ATPase activity of SWI/SNF, despite the relevance in cancer, particularly in BRG1-deficient cases.
  • New allosteric dual inhibitors targeting both BRM and BRG1 have been developed, showing potential to reduce BRM-dependent gene expression and demonstrate anti-cancer effects in a BRG1-mutant lung tumor model, providing insights into SWI/SNF functions in various health contexts.
View Article and Find Full Text PDF

Methanol is generally metabolized through a pathway initiated by a cobalamine-containing methanol methyltransferase by anaerobic methylotrophs (such as methanogens and acetogens), or through oxidation to formaldehyde using a methanol dehydrogenase by aerobes. Methanol is an important substrate in deep-subsurface environments, where thermophilic sulfate-reducing bacteria of the genus Desulfotomaculum have key roles. Here, we study the methanol metabolism of Desulfotomaculum kuznetsovii strain 17, isolated from a 3000-m deep geothermal water reservoir.

View Article and Find Full Text PDF

When related species meet upon postglacial range expansion, hybrid zones are frequently formed. Theory predicts that such zones may move over the landscape until equilibrium conditions are reached. One hybrid zone observed to be moving in historical times (1950-1979) is that of the pond-breeding salamanders and in western France.

View Article and Find Full Text PDF

A genome and physiological comparison was made of the type strains of species belonging to subgroup 1a and of '' strain MI-1. Phenotypically, '' strain MI-1 can be distinguished from the other described species of subgroup 1a by its ability to grow with propionate and butyrate. In addition, the strain is able to use a variety of metals as electron acceptors.

View Article and Find Full Text PDF

The Sporomusa genus comprises anaerobic spore-forming acetogenic bacteria that stain Gram-negative. Sporomusa species typically grow with one-carbon substrates and N-methylated compounds. In the degradation of these compounds methyltransferases are involved.

View Article and Find Full Text PDF

Desulfotomaculum gibsoniae is a mesophilic member of the polyphyletic spore-forming genus Desulfotomaculum within the family Peptococcaceae. This bacterium was isolated from a freshwater ditch and is of interest because it can grow with a large variety of organic substrates, in particular several aromatic compounds, short-chain and medium-chain fatty acids, which are degraded completely to carbon dioxide coupled to the reduction of sulfate. It can grow autotrophically with H2 + CO2 and sulfate and slowly acetogenically with H2 + CO2, formate or methoxylated aromatic compounds in the absence of sulfate.

View Article and Find Full Text PDF

Desulfotomaculum nigrificans and D. carboxydivorans are moderately thermophilic members of the polyphyletic spore-forming genus Desulfotomaculum in the family Peptococcaceae. They are phylogenetically very closely related and belong to 'subgroup a' of the Desulfotomaculum cluster 1.

View Article and Find Full Text PDF

The genus Desulfotomaculum, belonging to the Firmicutes, comprises strictly anaerobic and endospore-forming bacteria capable of dissimilatory sulfate reduction. These microorganisms are metabolically versatile and are widely distributed in the environment. Spore formation allows them to survive prolonged environmental stress.

View Article and Find Full Text PDF

In sulfate-reducing and methanogenic environments complex biopolymers are hydrolyzed and degraded by fermentative micro-organisms that produce hydrogen, carbon dioxide and short chain fatty acids. Degradation of short chain fatty acids can be coupled to methanogenesis or to sulfate-reduction. Here we study from a genome perspective why some of these micro-organisms are able to grow in syntrophy with methanogens and others are not.

View Article and Find Full Text PDF

Desulfotomaculum kuznetsovii is a moderately thermophilic member of the polyphyletic spore-forming genus Desulfotomaculum in the family Peptococcaceae. This species is of interest because it originates from deep subsurface thermal mineral water at a depth of about 3,000 m. D.

View Article and Find Full Text PDF
Article Synopsis
  • Tankyrase 1 and 2 are important enzymes in the Wnt pathway, and targeting them has become a focus for developing new drugs.
  • Researchers optimized a compound called XAV939 by improving its stability and efficiency, leading to the creation of new tankyrase inhibitors that are very effective.
  • One of these inhibitors, NVP-TNKS656, has been shown to effectively block Wnt pathway activity in mouse models and has good properties for potential use in further studies.
View Article and Find Full Text PDF

Desulfotomaculum ruminis Campbell and Postgate 1965 is a member of the large genus Desulfotomaculum which contains 30 species and is contained in the family Peptococcaceae. This species is of interest because it represents one of the few sulfate-reducing bacteria that have been isolated from the rumen. Here we describe the features of D.

View Article and Find Full Text PDF

Overexpression of the antiapoptotic members of the Bcl-2 family of proteins is commonly associated with cancer cell survival and resistance to chemotherapeutics. Here, we describe the structure-based optimization of a series of N-heteroaryl sulfonamides that demonstrate potent mechanism-based cell death. The role of the acidic nature of the sulfonamide moiety as it relates to potency, solubility, and clearance is examined.

View Article and Find Full Text PDF

The discovery of new Bcl-2 protein-protein interaction antagonists is described. We replaced the northern fragment of ABT737 (π-π stacking interactions) with structurally simplified hydrophobic cage structures with much reduced conformational flexibility and rotational freedom. The binding mode of the compounds was elucidated by X-ray crystallography, and the compounds showed excellent oral bioavailability and clearance in rat PK studies.

View Article and Find Full Text PDF

The first highly potent and selective PDE8 inhibitors are disclosed. The initial tetrahydroisoquinoline hit was transformed into a nipecotic amide series in order to address a reactive metabolite issue. Reduction of lipophilicity to address metabolic liabilities uncovered an interesting diastereomer-dependent trend in turnover by human microsomes.

View Article and Find Full Text PDF

Novel hygromycin A derivatives bearing a variety of functionalized aminocyclitol moieties have been synthesized in an effort to increase the antibacterial activity and drug-like properties of this class of agents. A systematic study of the effect of alkylation and removal of the hydroxyls of the aminocyclitol directed us to a series of alkylated aminocyclitol derivatives with improved gram-positive activity.

View Article and Find Full Text PDF

Galectin-3 (Gal-3) is a beta-galactoside binding lectin displaying both intracellular and extracellular immune functions. In Schistosoma mansoni infection, Gal-3 has been associated with the induction of a T helper 2 response. Whereas dendritic cells (DCs) play a pivotal role in the regulation of T cell differentiation, little is known about the regulation of Gal-3 expression in DCs.

View Article and Find Full Text PDF