33 research outputs found

    Imaging techniques for research and education of thermal and mechanical interactions of lasers with biological and model tissues

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    A setup based on color Schlieren techniques has been developed to study the interaction of energy sources, such as lasers, with biological tissues. This imaging technique enables real-time visualization of dynamic temperature gradients with high spatial and temporal resolution within a transparent tissue model. High-speed imaging techniques were combined in the setup to capture mechanical phenomena such as explosive vapor, cavitation bubbles, and shock waves. The imaging technique is especially used for qualitative studies because it is complex to obtain quantitative data by relating the colors in the images to temperatures. By positioning thermocouples in the field of view, temperature figures can be added in the image for correlation to colored areas induced by the temperature gradients. The color Schlieren setup was successfully used for various studies to obtain a better understanding of interaction of various laser, rf, and ultrasound devices used in medicine. The results contributed to the safety and the optimal settings of various medical treatments. Although the interaction of energy sources is simulated in model tissue, the video clips have proven to be of great value for educating researchers, surgeons, nurses, and students to obtain a better understanding of the mechanism of action during patient treatment

    Socially mediated induction and suppression of antibiosis during bacterial coexistence

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    Despite their importance for humans, there is little consensus on the function of antibiotics in nature for the bacteria that produce them. Classical explanations suggest that bacteria use antibiotics as weapons to kill or inhibit competitors, whereas a recent alternative hypothesis states that antibiotics are signals that coordinate cooperative social interactions between coexisting bacteria. Here we distinguish these hypotheses in the prolific antibiotic-producing genus Streptomyces and provide strong evidence that antibiotics are weapons whose expression is significantly influenced by social and competitive interactions between competing strains. We show that cells induce facultative responses to cues produced by competitors by (i) increasing their own antibiotic production, thereby decreasing costs associated with constitutive synthesis of these expensive products, and (ii) by suppressing antibiotic production in competitors, thereby reducing direct threats to themselves. These results thus show that although antibiotic production is profoundly social, it is emphatically not cooperative. Using computer simulations, we next show that these facultative strategies can facilitate the maintenance of biodiversity in a community context by converting lethal interactions between neighboring colonies to neutral interactions where neither strain excludes the other. Thus, just as bacteriocins can lead to increased diversity via rock–paper–scissors dynamics, so too can antibiotics via elicitation and suppression. Our results reveal that social interactions are crucial for understanding antibiosis and bacterial community dynamics, and highlight the potential of interbacterial interactions for novel drug discovery by eliciting pathways that mediate interference competition

    Pressure-standardised mammography does not affect visibility, contrast and sharpness of stable lesions

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    Introduction: A recent technological development allows pressure-standardised mammography by personalizing the compression force to the breast size and firmness. The technique has been shown to reduce pain and compression variability between consecutive exams, but also results in a slightly thicker compressed breast during exposure. This raises the question whether visibility, contrast and sharpness of lesions are affected? Methods: Four experienced radiologists compared 188 stable lesions and structures including (clusters of) calcifications, (oil) cysts and lymph nodes that were visible in mammograms obtained in 2009 with a pain-tolerance limited 18 daN target force compression protocol, and in 2014/2015 obtained with a 10 kPa (75 mmHg) pressure-standardised compression protocol. Observers were blinded for all DICOM metadata and rated which of the randomly ordered, side by side presented images had better lesion visibility, contrast and sharpness, or whether they saw no difference. They also indicated which overall image they preferred, if any, and whether the non-preferred image was still adequate. Statistical non inferiority is concluded when the lower limit of the 95% confidence interval of the 4-rater averaged new protocol better' proportions exceed the non-inferiority limit of 0.463. Results: In 2014/2015, the compressions were significantly milder, with on average 17% (mediolateral oblique) to 29% (craniocaudal) lower forces. Breasts remained on average 2.4% (1.4 mm) thicker. Dose was significantly lower (6.5%), which is explained by glandular atrophy. The 95% confidence interval lower limits are 0.479 for visibility, 0.473 for contrast, 0.488 for sharpness and 0.486 for preference, all exceeding the non-inferiority limit. Of the 60 non-preferred mammograms, multiple observers found only five to be inadequate: 4 obtained with the force protocol and 1 with the pressure protocol. Conclusion: Pain-reduced mammography with 10 kPa pressure-standardised compression has non inferior visibility, contrast and sharpness for stable lesions compared to pain-tolerance limited 18 daN target force compression. (C) 2016 Elsevier Ireland Ltd. All rights reserve

    Anti-MCP-1 gene therapy inhibits vascular smooth muscle cells proliferation and attenuates vein graft thickening both in vitro and in vivo

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    OBJECTIVE: Because late vein graft failure is caused by intimal hyperplasia (IH) and accelerated atherosclerosis, and these processes are thought to be inflammation driven, influx of monocytes is one of the first phenomena seen in IH, we would like to provide direct evidence for a role of the MCP-1 pathway in the development of vein graft disease. METHODS AND RESULTS: MCP-1 expression is demonstrated in various stages of vein graft disease in a murine model in which venous interpositions are placed in the carotid arteries of hypercholesterolemic ApoE3Leiden mice and in cultured human saphenous vein (HSV) segments in which IH occurs. The functional involvement of MCP-1 in vein graft remodeling is demonstrated by blocking the MCP-1 receptor CCR-2 using 7ND-MCP-1. 7ND-MCP1 gene transfer resulted in 51% reduction in IH in the mouse model, when compared with controls. In HSV cultures neointima formation was inhibited by 53%. In addition, we demonstrate a direct inhibitory effect of 7ND-MCP-1 on the proliferation of smooth muscle cell (SMC) in HSV cultures and in SMC cell cultures. CONCLUSIONS: These data, for the first time, prove that MCP-1 has a pivotal role in vein graft thickening due to intimal hyperplasia and accelerated atherosclerosi

    The efficacy of a blended intervention to improve physical activity and protein intake for optimal physical recovery after oncological gastrointestinal and lung cancer surgery, the Optimal Physical Recovery After Hospitalization (OPRAH) trial:study protocol for a randomized controlled multicenter trial

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    Background: Improving physical activity, especially in combination with optimizing protein intake, after surgery has a potential positive effect on recovery of physical functioning in patients after gastrointestinal and lung cancer surgery. The aim of this randomized controlled trial is to evaluate the efficacy of a blended intervention to improve physical activity and protein intake after hospital discharge on recovery of physical functioning in these patients. Methods: In this multicenter single-blinded randomized controlled trial, 161 adult patients scheduled for elective gastrointestinal or lung cancer surgery will be randomly assigned to the intervention or control group. The purpose of the Optimal Physical Recovery After Hospitalization (OPRAH) intervention is to encourage self-management of patients in their functional recovery, by using a smartphone application and corresponding accelerometer in combination with coaching by a physiotherapist and dietician during three months after hospital discharge. Study outcomes will be measured prior to surgery (baseline) and one, four, eight, and twelve weeks and six months after hospital discharge. The primary outcome is recovery in physical functioning six months after surgery, and the most important secondary outcome is physical activity. Other outcomes include lean body mass, muscle mass, protein intake, symptoms, physical performance, self-reported limitations in activities and participation, self-efficacy, hospital readmissions and adverse events. Discussion: The results of this study will demonstrate whether a blended intervention to support patients increasing their level of physical activity and protein intake after hospital discharge improves recovery in physical functioning in patients after gastrointestinal and lung cancer surgery. Trial registration: The trial has been registered at the International Clinical Trials Registry Platform at 14–10-2021 with registration number NL9793. Trial registration data are presented in Table 1

    UvA-DARE (Digital Academic Repository) Link to publication Citation for published version (APA): Calpainopathy-A Survey of Mutations and Polymorphisms

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    General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Download date: 29 Jun 2019 Am. J. Hum. Genet. 64:1524-1540, 1999 1524 Calpainopathy-A Survey of Mutations and Polymorphism
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