Publications by authors named "Geertsma R"

Background And Purpose:  Safety notices for medical devices such as total knee arthroplasty (TKA) implants may indicate problems in their design or performance that require corrective action to prevent patient harm. Safety notices are often published on national Ministries of Health or regulatory agencies websites. It is unknown whether problems triggering safety notices identify the same implants as those identified by registries as "outlier.

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Plants are frequently exposed to environmental challenges. Responses to sub-lethal abiotic stress combinations are complex and often distinct from responses to individual stresses and remain poorly understood. Investigating traits and molecular factors mediating acclimation to stress combinations is essential for the development of climate change-resilient field crops.

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Induction motor driven pumps are a staple in many sectors of industry, and crucial equipment in naval ships. Such machines can suffer from a wide variety of issues, which may cause it to not perform its function. This can either be due to degradation of components over time, or due to incorrect installation or usage.

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Usage of injectable dermal fillers applied for aesthetic purposes has extensively increased over the years. As such, the number of related adverse reactions has increased, including patients showing severe complications such as product migration, topical swelling and inflammatory reactions of the skin. In order to understand the underlying molecular events of these adverse reactions we performed a genome-wide gene expression study on the multi-cell type human Phenion® Full-Thickness Skin Model exposed to five experimental hyaluronic acid (HA) preparations with increasing cross-linking degree, four commercial fillers from Perfectha®, and non-resorbable filler Bio-Alcamid®.

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River water is an important source of Dutch drinking water. For this reason, continuous monitoring of river water quality is needed. However, comprehensive chemical analyses with high-resolution gas chromatography [GC]-mass spectrometry [MS]/liquid chromatography [LC]-MS are quite tedious and time consuming; this makes them poorly fit for routine water quality monitoring and, therefore, many pollution events are missed.

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Nanotechnologies enable great opportunities for the development and use of innovative (nano)medicines. As is common for scientific and technical developments, recognized safety evaluation methods for regulatory purposes are lagging behind. The specific properties responsible for the desired functioning also hamper the safety evaluation of such products.

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Resorbable tissue fillers for aesthetic purposes can induce severe complications including product migration, late swelling, and inflammatory reactions. The relation between product characteristics and adverse effects is not well understood. We hypothesized that the degree of cross-linking hyaluronic acid (HA) fillers was associated with the occurrence of adverse effects.

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The identification of regulatory challenges for nanotechnology-enabled health products, followed by discussions with the involved stakeholders, is the first step towards a strategic planning of how such challenges can be successfully addressed in the future. In order to better understand whether the identified regulatory needs are sector-specific for health products or might also hinder the progress in other domains, the REFINE consortium reached out to communities representing other sectors that also exploit the potential of nanotechnology, i.e.

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The application of nanomaterials in medicine has led to novel pharmaceuticals and medical devices that have demonstrated a strong potential for increasing the efficacy/performance and safety of therapeutic and diagnostic procedures to address a wide range of diseases. However, the successful translation of these technologies from their inception (proof-of-concept) to clinical practice has been challenged by substantial gaps in the scientific and technical capacity of R&D companies, especially SMEs, to keep up with the ever-evolving regulatory expectations in the emerging area of nanomedicine. To address these challenges, the EU Horizon 2020 project REFINE has developed a Decision Support System (DSS) to support developers of nanotechnology-enabled health products in bringing their products to the clinic.

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Various nanomedicinal products (NMPs) have been reported to induce an adverse immune response, which may be related to their tendency to accumulate in or target cells of the immune system. Therefore, before their market authorization, NMPs should be thoroughly evaluated for their immunotoxic potential. Nonclinical regulatory immunotoxicity testing of nonbiological medicinal products, including NMPs, is currently performed by following the guideline S8 "Immunotoxicity Studies for Human Pharmaceuticals" of the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH).

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: Patients with severe aortic stenosis and regurgitation who are inoperable or at high-risk for surgery can be treated with transcatheter aortic valve replacement (TAVR). The aim of this study was to provide a comprehensive overview of the literature of TAVR and reported clinical and performance outcomes. : A total of 16 devices, described in 204 articles describing clinical and performance outcomes, were included.

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Nanomaterials and nanomedicinal products tend to interfere with various commonly used assays, including regulatory required endotoxin detection methods for medicines. We developed a method to quantify endotoxin levels that is compatible with nanomaterials and nanomedicinal products. The method is based on measuring endotoxin indirectly via 3-hydroxylated fatty acids of lipid-A, using Ultra High Performance Liquid Chromatography coupled with mass spectrometry.

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Due to their specific properties and pharmacokinetics, nanomedicinal products (NMPs) may present different toxicity and side effects compared to non-nanoformulated, conventional medicines. To facilitate the safety assessment of NMPs, we aimed to gain insight into toxic effects specific for NMPs by systematically analyzing the available toxicity data on approved NMPs in the European Union. In addition, by comparing five sets of products with the same active pharmaceutical ingredient (API) in a conventional formulation versus a nanoformulation, we aimed to identify any side effects specific for the nano aspect of NMPs.

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Nanomaterials (NMs) are attractive for biomedical and pharmaceutical applications because of their unique physicochemical and biological properties. A major application area of NMs is drug delivery. Many nanomedicinal products (NMPs) currently on the market or in clinical trials are most often based on liposomal products or polymer conjugates.

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Symbiotic relationships are common in nature, and are important for individual fitness and sustaining species populations. Global change is rapidly altering environmental conditions, but, with the exception of coral-microalgae interactions, we know little of how this will affect symbiotic relationships. We here test how the effects of ocean acidification, from rising anthropogenic CO2 emissions, may alter symbiotic interactions between juvenile fish and their jellyfish hosts.

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Aim: A horizon scan of nanomedicinal product on the market or undergoing clinical investigation by analyzing the current nanomedicinal landscape.

Materials & Methods: The horizon scan includes a search of literature, clinical trial registries and the internet.

Results: This horizon scan yielded 175 nanomedicinal products.

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Background: Point-of-care (POC) tests are devices or test strips that can be used near or at the site where care is delivered to patients, enabling a relatively fast diagnosis. Although many general practitioners (GPs) in the Netherlands are using POC tests in their practice, little is known on how they manage the corresponding patient safety aspects.

Methods: To obtain information on this aspect, an invitation to participate in a web-based questionnaire was sent to a random sample of 750 GP practices.

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Treatment with injectable tissue fillers for aesthetic purposes is increasingly popular. In parallel with this success, questions related to the safety of these treatments and the products involved are being raised more prominently. To gain insight in the safety aspects of injectable tissue fillers, we performed a literature review to collect studies reporting clinical data of injectable tissue fillers.

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Objectives: This study aimed to investigate the technical documentation of manufacturers on issues of safe use of their device in a home setting.

Methods: Three categories of equipment were selected: infusion pumps, ventilators, and dialysis systems. Risk analyses, instructions for use, labels, and post market surveillance procedures were requested from manufacturers.

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In recent years, an increasing number of applications and products containing or using nanomaterials have become available. This has raised concerns that some of these materials may introduce new risks for humans or the environment. A clear definition to discriminate nanomaterials from other materials is prerequisite to include provisions for nanomaterials in legislation.

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Humans and the environment can come into contact with nanomaterials through a wide range of applications during all stages of the life cycle of nanoproducts. The aim of this commentary is to present an assessment of the potential for exposure and thus identify possible environmental, health and safety (EHS) issues for nanomaterials used in 10 technology sectors. We analysed all life cycle stages with regard to potential for exposure of workers, consumers/patients, and the environment.

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Gold nanoparticles of 10 nm and 250 nm were intravenously injected in rats. At 24 h after administration, tissues were collected and prepared for transmission electron microscopy (TEM). In the liver and spleen of animals treated with 10 nm gold nanoparticles, groups of nanoparticles were observed that could be positively identified by Energy Dispersive X-ray (EDX) analysis to contain gold, while nanoparticles could not be detected in the heart, kidney and brain.

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Blood kinetics and tissue distribution of 20, 80 and 110 nm silver nanoparticles were investigated in rats up to 16 days after intravenous administration once daily for 5 consecutive days. Following both single and repeated injection, silver nanoparticles disappeared rapidly from the blood and distributed to all organs evaluated (liver, lungs, spleen, brain, heart, kidneys and testes) regardless of size. The 20 nm particles distributed mainly to liver, followed by kidneys and spleen, whereas the larger particles distributed mainly to spleen followed by liver and lung.

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Polymer-water partition coefficients (Kpw) of hexachlorobenzene, 41 polychlorinated biphenyls (PCBs), and 26 polyaromatic hydrocarbons (PAHs) were determined for low-density polyethylene (LDPE) and five different silicone rubbers. Partition coefficients were determined in ultra pure water and in a range of methanol-water mixtures. Different cosolvent models for the effect of methanol concentration on the polymer-mixture partition coefficient (Kpm) were used to validate the Kpw in pure water.

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A kinetic study was performed to determine the influence of particle size on the in vivo tissue distribution of spherical-shaped gold nanoparticles in the rat. Gold nanoparticles were chosen as model substances as they are used in several medical applications. In addition, the detection of the presence of gold is feasible with no background levels in the body in the normal situation.

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