Real-time intravital multiphoton microscopy to visualize focused ultrasound and microbubble treatments to increase blood-brain barrier permeability

The blood-brain barrier (BBB) is a key challenge for the successful delivery of drugs to the brain. Ultrasound exposure in the presence of microbubbles has emerged as an effective method to transiently and locally increase the permeability of the BBB, facilitating para- and transcellular transport of drugs across the BBB. Imaging the vasculature during ultrasound-microbubble treatment will provide valuable and novel insights on the mechanisms and dynamics of ultrasound-microbubble treatments in the brain. Here, we present an experimental procedure for intravital multiphoton microscopy using a cranial window aligned with a ring transducer and a 20x objective lens. This set-up enables high spatial and temporal resolution imaging of the brain during ultrasound-microbubble treatments. Optical access to the brain is obtained via an open-skull cranial window. Briefly, a 3-4 mm diameter piece of the skull is removed, and the exposed area of the brain is sealed with a glass coverslip. A 0.82 MHz ring transducer, which is attached to a second glass coverslip, is mounted on top. Agarose (1% w/v) is used between the coverslip of the transducer and the coverslip covering the cranial window to prevent air bubbles, which impede ultrasound propagation. When sterile surgery procedures and anti-inflammatory measures are taken, ultrasound-microbubble treatments and imaging sessions can be performed repeatedly over several weeks. Fluorescent dextran conjugates are injected intravenously to visualize the vasculature and quantify ultrasound-microbubble induced effects (e.g., leakage kinetics, vascular changes). This paper describes the cranial window placement, ring transducer placement, imaging procedure, common troubleshooting steps, as well as advantages and limitations of the method.publishedVersio

Digoxin-specific antibodies: a novel dosing strategy

Digoxin-specific antibodies (digoxin-Fabs) are of value in the treatment of a strongly suspected or a known, potentially life-threatening digoxin toxicity. These antibodies are not registered for use in Europe; therefore Dutch hospital pharmacies are not allowed to keep them in stock. In the Netherlands, digoxin-Fabs are stored in a national calamity stock of emergency medicines at the National Institute for Public Health and the Environment. In the case of a medical emergency, digoxin-Fabs are available after contact with the Dutch Poisons Information Centre. Recent studies have shown that the dose of digoxin-Fabs required to effectively treat digoxin toxicity is lower than previously thought. In this article, we present the adjusted digoxin-Fab dosing strategy currently recommended by the Dutch Poisons Information Centre ( www.vergiftigingen.info ). This new dose titration strategy is safe and effective and has a cost-saving side-effect

Evidence of a sudden increase in α-chloralose poisoning in dogs and cats in the Netherlands between 2018 and 2021

BACKGROUND: After changes in European Union biocide legislation, the Dutch Poisons Information Center observed a strong increase in information requests concerning dogs and cats exposed to α-chloralose. To investigate whether α-chloralose-based rodenticides are safe for non-professional use, additional information regarding poisoning scenarios and clinical course was collected. METHODS: Veterinarians reporting α-chloralose exposure over a 2.5-year period were contacted by mail for follow-up information concerning exposure scenario, product formulation, clinical course and treatment, and outcome. In total, information was collected for 96 dogs and 41 cats. RESULTS: Fifty-three of 96 dogs and 17 of 19 cats known to have been exposed to α-chloralose-based rodenticides developed signs of central nervous system (CNS) depression or sensory-induced CNS excitation. Mortality in dogs and cats following exposure was 1% and 18%, respectively. An additional 22 cats presented with clinical signs suggestive of α-chloralose poisoning, with a mortality of 5%. LIMITATIONS: Exposure to α-chloralose was not confirmed by biochemical analyses. CONCLUSION: Dogs and especially cats were at risk of poisoning from α-chloralose. If criteria such as acute toxicity and risk of (secondary) poisoning are applied during the approval of α-chloralose-based rodenticides, similar to anticoagulant-based rodenticides, it can be concluded that α-chloralose is also not safe for non-professional use

Malnutrition assessment methods in adult patients with tuberculosis:A systematic review

OBJECTIVES: Malnutrition is associated with a twofold higher risk of dying in patients with tuberculosis (TB) and considered an important potentially reversible risk factor for failure of TB treatment. The construct of malnutrition has three domains: intake or uptake of nutrition; body composition and physical and cognitive function. The objectives of this systematic review are to identify malnutrition assessment methods, and to quantify how malnutrition assessment methods capture the international consensus definition for malnutrition, in patients with TB. DESIGN: Different assessment methods were identified. We determined the extent of capturing of the three domains of malnutrition, that is, intake or uptake of nutrition, body composition and physical and cognitive function. RESULTS: Seventeen malnutrition assessment methods were identified in 69 included studies. In 53/69 (77%) of studies, body mass index was used as the only malnutrition assessment method. Three out of 69 studies (4%) used a method that captured all three domains of malnutrition. CONCLUSIONS: Our study focused on published articles. Implementation of new criteria takes time, which may take longer than the period covered by this review. Most patients with TB are assessed for only one aspect of the conceptual definition of malnutrition. The use of international consensus criteria is recommended to establish uniform diagnostics and treatment of malnutrition. PROSPERO REGISTRATION NUMBER: CRD42019122832

Individualized treatment of multidrug-resistant tuberculosis using therapeutic drug monitoring

AbstractObjective/BackgroundGlobally, approximately 50% of patients with multidrug-resistant tuberculosis (MDR-TB) experience treatment failure. MDR-TB treatment is hindered by adverse events, toxicity of the second-line anti-TB drugs, logistics and costs, especially in low-income countries, and problems with medication adherence. Pharmacokinetic variability is also attributed as one of the reasons contributing to treatment failure. In our reference Tuberculosis Center Beatrixoord (University Medical Center Groningen, Groningen, The Netherlands), we strive to individualize treatment of all MDR-TB patients based on drug-susceptibility testing using minimal inhibitory concentrations and pharmacokinetic parameters. The aim of this work is to give an overview of our efforts to individualize treatment of MDR-TB patients and to provide insights into practical tools that might be implemented in other clinical settings worldwide.MethodsWe critically looked at clinical practice guidelines implemented in our center to give an overview of practically applied tools to individualize treatment of MDR-TB patients. Furthermore, we selected studies carried out in our clinic on treatment individualization of MDR-TB patients and combined their results with recent studies in this area to suggest practical tools for implementation in other clinical settings.ResultsWe regularly perform therapeutic drug monitoring (TDM) of several second-line anti-TB drugs, such as amikacin, kanamycin, linezolid, and moxifloxacin. New analyses of Group D and experimental drugs, such as co-trimoxazole (sulfamethoxazole/trimethoprim), bedaquiline, delamanid, and clarithromycin, have been or are being developed. By implementing TDM methods, variability in pharmacokinetics is often detected and treatment is adjusted, possibly preventing toxicity in patients with very high drug exposure or treatment failure, or resistance in patients with very low drug exposure. Over the past 10years in the Netherlands, 86% of 104 patients had a successful outcome using a median of six active drugs. Many studies were performed using dried blood spot (DBS) analysis of second-line TB drugs. These studies may be used to implement TDM worldwide, even in low-income countries. Furthermore, several studies are performed to determine limited sampling strategies (LSSs). By limiting the number samples required for adequate sampling, TDM will become easier to implement. Other examples of LSSs included development of oral fluid sampling methods or development of semiquantitative thin-layer chromatography methods.ConclusionTDM is highly valuable to individualize and optimize treatment of complex MDR-TB patients. TDM is routinely applied in Tuberculosis Center Beatrixoord, and high success rates for treatment of MDR-TB patients have been achieved. DBS and LSS make implementation of TDM feasible, even in low- and middle-income countries

Dutch orthopedic thromboprophylaxis: a 5-year follow-up survey

Background and purpose Previous surveys in the Netherlands have revealed that guidelines regarding orthopedic thromboprophylaxis were not followed and that a wide variation in protocols exists. This survey was performed to assess the current use of thromboprophylactic modalities and to compare it with the results of a previous survey

Job Resources and Matching Active Coping Styles as Moderators of the Longitudinal Relation Between Job Demands and Job Strain

Background: Only in a few longitudinal studies it has been examined whether job resources should be matched to job demands to show stress-buffering effects of job resources (matching hypothesis), while there are no empirical studies in which the moderating effect of matching personal characteristics on the stress-buffering effect of job resources has been examined. Purpose: In this study, both the matching hypothesis and the moderating effect of matching active coping styles were examined with respect to the longitudinal relation between job demands, job resources, and job strain.Method: The study group consisted of 317 beginning teachers from Belgium. The two-wave survey data with a 1-year time lag were analyzed by means of structural equation modeling and multiple group analyses. Results: Data did not support the matching hypothesis. In addition, no support was found for the moderating effect of specific active coping styles, irrespective of the level of match. Conclusion: To show stress-buffering effects of job resources, it seems to make no difference whether or not specific types of job demands and job resources are matched, and whether or not individual differences in specific active coping styles are taken into account