85 research outputs found

    Development of a Multimodal Apparatus to Generate Biomechanically Reproducible Spinal Cord Injuries in Large Animals

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    Rodents are widespread animal models in spinal cord injury (SCI) research. They have contributed to obtaining important information. However, some treatments only tested in rodents did not prove efficient in clinical trials. This is probably a result of significant differences in the physiology, anatomy, and complexity between humans and rodents. To bridge this gap in a better way, a few research groups use pig models for SCI. Here we report the development of an apparatus to perform biomechanically reproducible SCI in large animals, including pigs. We present the iterative process of engineering, starting with a weight-drop system to ultimately produce a spring-load impactor. This device allows a graded combination of a contusion and a compression injury. We further engineered a device to entrap the spinal cord and prevent it from escaping at the moment of the impact. In addition, it provides identical resistance around the cord, thereby, optimizing the inter-animal reproducibility. We also present other tools to straighten the vertebral column and to ease the surgery. Sensors mounted on the impactor provide information to assess the inter-animal reproducibility of the impacts. Further evaluation of the injury strength using neurophysiological recordings, MRI scans, and histology shows consistency between impacts. We conclude that this apparatus provides biomechanically reproducible spinal cord injuries in pigs

    Abnormal motor activity during anaesthesia in a dog: a case report

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    Seizures or convulsions that occur during anaesthesia in veterinary patients are infrequently reported in the literature. Consequently, the incidence of such events is unknown. Several drugs commonly used in clinical veterinary anaesthesia have been shown to induce epileptiform activity in both human clinical patients and experimental candidates. The present case report describes convulsions in a four-year old male Bernese mountain dog during maintenance of anaesthesia with isoflurane after premedication with acepromazine and methadone followed by co-induction with propofol and ketamine. The dog had no history of previous convulsions. The use of several sedative and anaesthetic drugs makes it difficult to find one single causative pharmaceutical

    Scaling behaviour for the water transport in nanoconfined geometries

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    The transport of water in nanoconfined geometries is different from bulk phase and has tremendous implications in nanotechnology and biotechnology. Here molecular dynamics is used to compute the self-diffusion coefficient D of water within nanopores, around nanoparticles, carbon nanotubes and proteins. For almost 60 different cases, D is found to scale linearly with the sole parameter theta as D(theta)=DB[1+(DC/DB-1)theta], with DB and DC the bulk and totally confined diffusion of water, respectively. The parameter theta is primarily influenced by geometry and represents the ratio between the confined and total water volumes. The D(theta) relationship is interpreted within the thermodynamics of supercooled water. As an example, such relationship is shown to accurately predict the relaxometric response of contrast agents for magnetic resonance imaging. The D(theta) relationship can help in interpreting the transport of water molecules under nanoconfined conditions and tailoring nanostructures with precise modulation of water mobility

    SupportPrim—a computerized clinical decision support system for stratified care for patients with musculoskeletal pain complaints in general practice: study protocol for a randomized controlled trial

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    BackgroundMusculoskeletal disorders represented 149 million years lived with disability world-wide in 2019 and are the main cause of years lived with disability worldwide. Current treatment recommendations are based on “one-size fits all” principle, which does not take into account the large degree of biopsychosocial heterogeneity in this group of patients. To compensate for this, we developed a stratified care computerized clinical decision support system for general practice based on patient biopsychosocial phenotypes; furthermore, we added personalized treatment recommendations based on specific patient factors to the system. In this study protocol, we describe the randomized controlled trial for evaluating the effectiveness of computerized clinical decision support system for stratified care for patients with common musculoskeletal pain complaints in general practice. The aim of this study is to test the effect of a computerized clinical decision support system for stratified care in general practice on subjective patient outcome variables compared to current care.MethodsWe will perform a cluster-randomized controlled trial with 44 general practitioners including 748 patients seeking their general practitioner due to pain in the neck, back, shoulder, hip, knee, or multisite. The intervention group will use the computerized clinical decision support system, while the control group will provide current care for their patients. The primary outcomes assessed at 3 months are global perceived effect and clinically important improvement in function measured by the Patient-Specific Function Scale (PSFS), while secondary outcomes include change in pain intensity measured by the Numeric Rating Scale (0–10), health-related quality of life (EQ-5D), general musculoskeletal health (MSK-HQ), number of treatments, use of painkillers, sick-leave grading and duration, referral to secondary care, and use of imaging.DiscussionThe use of biopsychosocial profile to stratify patients and implement it in a computerized clinical decision support system for general practitioners is a novel method of providing decision support for this patient group. The study aim to recruit patients from May 2022 to March 2023, and the first results from the study will be available late 2023.Trial registrationThe trial is registered in ISRCTN 11th of May 2022: 14,067,965

    Describing transport across complex biological interfaces

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    It has long been known that proteins are capable of transporting ions against a gradient in the chemical potential, using the energy available from a chemical reaction. This is called active transport. A well studied example is the Ca2+-transport by means of hydrolysis of adenosine triphoshpate (ATP) at the surface of the Ca2+-ATPase in sarcoplasmic reticulum. The cycle of events is known to be reversible, and has recently also been associated with a characteristic, and also reversible, heat production. We use the case of the Ca2+-ATPase to present and discuss various central theoretical approaches to describe active transport, with focus on two schools of development, namely the kinetic and the thermodynamic schools. Among the kinetic descriptions, Hill's diagram method gives the most sophisticated description, reducing to the common Post-Albers scheme with simple enzyme kinetic reactions. Among the thermodynamic approaches, we review the now classical approach of Katchalsky and Curran, and its extension to proper pathways by Caplan and Essig, before the most recent development based on mesoscopic theory is outlined. The mesoscopic approach gives a non-linear theory compatible with Hill's most general method when the active transport is isothermal. We show how the old question of scalar-vector coupling is resolved using rules for non-equilibrium thermodynamics for interfaces. Also thermal driving forces can then be accounted for. Essential physical concepts behind all methods are presented and advantages/deficiencies are pointed out. Emphasis is made on the connection to experiments
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